cfa92b6d52
1092 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
John Stultz
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cfa92b6d52 |
locking/ww_mutex/test: Make sure we bail out instead of livelock
I've seen what appears to be livelocks in the stress_inorder_work() function, and looking at the code it is clear we can have a case where we continually retry acquiring the locks and never check to see if we have passed the specified timeout. This patch reworks that function so we always check the timeout before iterating through the loop again. I believe others may have hit this previously here: https://lore.kernel.org/lkml/895ef450-4fb3-5d29-a6ad-790657106a5a@intel.com/ Reported-by: Li Zhijian <zhijianx.li@intel.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230922043616.19282-4-jstultz@google.com |
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John Stultz
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bccdd80890 |
locking/ww_mutex/test: Fix potential workqueue corruption
In some cases running with the test-ww_mutex code, I was seeing odd behavior where sometimes it seemed flush_workqueue was returning before all the work threads were finished. Often this would cause strange crashes as the mutexes would be freed while they were being used. Looking at the code, there is a lifetime problem as the controlling thread that spawns the work allocates the "struct stress" structures that are passed to the workqueue threads. Then when the workqueue threads are finished, they free the stress struct that was passed to them. Unfortunately the workqueue work_struct node is in the stress struct. Which means the work_struct is freed before the work thread returns and while flush_workqueue is waiting. It seems like a better idea to have the controlling thread both allocate and free the stress structures, so that we can be sure we don't corrupt the workqueue by freeing the structure prematurely. So this patch reworks the test to do so, and with this change I no longer see the early flush_workqueue returns. Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230922043616.19282-3-jstultz@google.com |
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John Stultz
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4812c54dc0 |
locking/ww_mutex/test: Use prng instead of rng to avoid hangs at bootup
Booting w/ qemu without kvm, and with 64 cpus, I noticed we'd sometimes hung task watchdog splats in get_random_u32_below() when using the test-ww_mutex stress test. While entropy exhaustion is no longer an issue, the RNG may be slower early in boot. The test-ww_mutex code will spawn off 128 threads (2x cpus) and each thread will call get_random_u32_below() a number of times to generate a random order of the 16 locks. This intense use takes time and without kvm, qemu can be slow enough that we trip the hung task watchdogs. For this test, we don't need true randomness, just mixed up orders for testing ww_mutex lock acquisitions, so it changes the logic to use the prng instead, which takes less time and avoids the watchdgos. Feedback would be appreciated! Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230922043616.19282-2-jstultz@google.com |
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Thomas Gleixner
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45f67f30a2 |
locking/rtmutex: Add a lockdep assert to catch potential nested blocking
There used to be a BUG_ON(current->pi_blocked_on) in the lock acquisition functions, but that vanished in one of the rtmutex overhauls. Bring it back in form of a lockdep assert to catch code paths which take rtmutex based locks with current::pi_blocked_on != NULL. Reported-by: Crystal Wood <swood@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: "Peter Zijlstra (Intel)" <peterz@infradead.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230908162254.999499-7-bigeasy@linutronix.de |
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Sebastian Andrzej Siewior
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d14f9e930b |
locking/rtmutex: Use rt_mutex specific scheduler helpers
Have rt_mutex use the rt_mutex specific scheduler helpers to avoid recursion vs rtlock on the PI state. [[ peterz: adapted to new names ]] Reported-by: Crystal Wood <swood@redhat.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230908162254.999499-6-bigeasy@linutronix.de |
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Sebastian Andrzej Siewior
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af9f006393 |
locking/rtmutex: Avoid unconditional slowpath for DEBUG_RT_MUTEXES
With DEBUG_RT_MUTEXES enabled the fast-path rt_mutex_cmpxchg_acquire() always fails and all lock operations take the slow path. Provide a new helper inline rt_mutex_try_acquire() which maps to rt_mutex_cmpxchg_acquire() in the non-debug case. For the debug case it invokes rt_mutex_slowtrylock() which can acquire a non-contended rtmutex under full debug coverage. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230908162254.999499-3-bigeasy@linutronix.de |
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Linus Torvalds
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d68b4b6f30 |
- An extensive rework of kexec and crash Kconfig from Eric DeVolder
("refactor Kconfig to consolidate KEXEC and CRASH options").
- kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
couple of macros to args.h").
- gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
commands").
- vsprintf inclusion rationalization from Andy Shevchenko
("lib/vsprintf: Rework header inclusions").
- Switch the handling of kdump from a udev scheme to in-kernel handling,
by Eric DeVolder ("crash: Kernel handling of CPU and memory hot
un/plug").
- Many singleton patches to various parts of the tree
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Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- An extensive rework of kexec and crash Kconfig from Eric DeVolder
("refactor Kconfig to consolidate KEXEC and CRASH options")
- kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
couple of macros to args.h")
- gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
commands")
- vsprintf inclusion rationalization from Andy Shevchenko
("lib/vsprintf: Rework header inclusions")
- Switch the handling of kdump from a udev scheme to in-kernel
handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
hot un/plug")
- Many singleton patches to various parts of the tree
* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
document while_each_thread(), change first_tid() to use for_each_thread()
drivers/char/mem.c: shrink character device's devlist[] array
x86/crash: optimize CPU changes
crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
crash: hotplug support for kexec_load()
x86/crash: add x86 crash hotplug support
crash: memory and CPU hotplug sysfs attributes
kexec: exclude elfcorehdr from the segment digest
crash: add generic infrastructure for crash hotplug support
crash: move a few code bits to setup support of crash hotplug
kstrtox: consistently use _tolower()
kill do_each_thread()
nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
scripts/bloat-o-meter: count weak symbol sizes
treewide: drop CONFIG_EMBEDDED
lockdep: fix static memory detection even more
lib/vsprintf: declare no_hash_pointers in sprintf.h
lib/vsprintf: split out sprintf() and friends
kernel/fork: stop playing lockless games for exe_file replacement
adfs: delete unused "union adfs_dirtail" definition
...
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Linus Torvalds
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97efd28334 |
Misc x86 cleanups.
The following commit deserves special mention:
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Linus Torvalds
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68cadad11f |
RCU pull request for v6.6
doc.2023.07.14b: Documentation updates. fixes.2023.08.16a: Miscellaneous fixes, perhaps most notably simplifying SRCU_NOTIFIER_INIT() as suggested. rcu-tasks.2023.07.24a: RCU Tasks updates, most notably treating Tasks RCU callbacks as lazy while still treating synchronous grace periods as urgent. Also fixes one bug that restores the ability to apply debug-objects to RCU Tasks and another that fixes a race condition that could result in false-positive failures of the boot-time self-test code. rcuscale.2023.07.14b: RCU-scalability performance-test updates, most notably adding the ability to measure the RCU-Tasks's grace-period kthread's CPU consumption. This proved quite useful for the rcu-tasks.2023.07.24a work. refscale.2023.07.14b: Reference-acquisition/release performance-test updates, including a fix for an uninitialized wait_queue_head_t. torture.2023.08.14a: Miscellaneous torture-test updates. torturescripts.2023.07.20a: Torture-test scripting updates, including removal of the non-longer-functional formal-verification scripts, test builds of individual RCU Tasks flavors, better diagnostics for loss of connectivity for distributed rcutorture tests, disabling of reboot loops in qemu/KVM-based rcutorture testing, and passing of init parameters to rcutorture's init program. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEbK7UrM+RBIrCoViJnr8S83LZ+4wFAmTjkssTHHBhdWxtY2tA a2VybmVsLm9yZwAKCRCevxLzctn7jITND/9zEqYNbeFrcBs/YaHdoAjsNgOt1IYN csfF/KArVgdvmrwlV/nEaQMLaJcw9X7DVU5+7E2JbbDaB/2FSacseNyKk6mfgSVK /0rnTOXpqI9/T1HiJObWZvDQFuKL12bfteXWGJg1sMt2JUGZ4nAWhdZ3xRjp2XkO 89qB5r0fF8gyGwvQ3M29ss8T9Oy0uUNJmDY/QyVxHM6dhkpSAezFffKzD7C4zkSV WucRTpYJ7bs6otBGtVmwz3x60UAuLwcVfQyB+CTbnGLsps9yAYU+1DDVdm7olcr3 ARXMeboeodMvy9jWXhtbWRVAAob4lVUDXQN27kb4sBgroRQBfQXMuByRAU6s0VtX frOl6rlbORuAetsC8wFL0IFVn4yTpvXKbYw7h1MXTs7gVVbl33O9FieGvWu0r79/ VR4Xw+JbmYWtyvFV8Zaq4iIEcOe+PeNH6u0bPx+htsHYd1+DUG2UY0MVmJQ3a4sb ygejA6mguCk7KBzWab8wdDpgAfhNwg0T9a+LQYcaskuD5SSWjYqqg6i1ulqqqyiE bOfRKDX4mWmAobWKHLssqUrjiLbxfygIaHjCrt7rWJKPIs1bK/WfWa4JbrE0NRwK 9IDd1lWc9C+zoUpjyZWSG3ahK5lWo2u4sPNoRtMQjowjobIz1cBhaEwmFe72bG7C FCKb7Da2oUaLOw== =EujZ -----END PGP SIGNATURE----- Merge tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Documentation updates - Miscellaneous fixes, perhaps most notably simplifying SRCU_NOTIFIER_INIT() as suggested - RCU Tasks updates, most notably treating Tasks RCU callbacks as lazy while still treating synchronous grace periods as urgent. Also fixes one bug that restores the ability to apply debug-objects to RCU Tasks and another that fixes a race condition that could result in false-positive failures of the boot-time self-test code - RCU-scalability performance-test updates, most notably adding the ability to measure the RCU-Tasks's grace-period kthread's CPU consumption. This proved quite useful for the RCU Tasks work - Reference-acquisition/release performance-test updates, including a fix for an uninitialized wait_queue_head_t - Miscellaneous torture-test updates - Torture-test scripting updates, including removal of the non-longer-functional formal-verification scripts, test builds of individual RCU Tasks flavors, better diagnostics for loss of connectivity for distributed rcutorture tests, disabling of reboot loops in qemu/KVM-based rcutorture testing, and passing of init parameters to rcutorture's init program * tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (64 commits) rcu: Use WRITE_ONCE() for assignments to ->next for rculist_nulls rcu: Make the rcu_nocb_poll boot parameter usable via boot config rcu: Mark __rcu_irq_enter_check_tick() ->rcu_urgent_qs load srcu,notifier: Remove #ifdefs in favor of SRCU Tiny srcu_usage rcutorture: Stop right-shifting torture_random() return values torture: Stop right-shifting torture_random() return values torture: Move stutter_wait() timeouts to hrtimers torture: Move torture_shuffle() timeouts to hrtimers torture: Move torture_onoff() timeouts to hrtimers torture: Make torture_hrtimeout_*() use TASK_IDLE torture: Add lock_torture writer_fifo module parameter torture: Add a kthread-creation callback to _torture_create_kthread() rcu-tasks: Fix boot-time RCU tasks debug-only deadlock rcu-tasks: Permit use of debug-objects with RCU Tasks flavors checkpatch: Complain about unexpected uses of RCU Tasks Trace torture: Cause mkinitrd.sh to indicate failure on compile errors torture: Make init program dump command-line arguments torture: Switch qemu from -nographic to -display none torture: Add init-program support for loongarch torture: Avoid torture-test reboot loops ... |
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Helge Deller
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0a6b58c5cd |
lockdep: fix static memory detection even more
On the parisc architecture, lockdep reports for all static objects which are in the __initdata section (e.g. "setup_done" in devtmpfs, "kthreadd_done" in init/main.c) this warning: INFO: trying to register non-static key. The warning itself is wrong, because those objects are in the __initdata section, but the section itself is on parisc outside of range from _stext to _end, which is why the static_obj() functions returns a wrong answer. While fixing this issue, I noticed that the whole existing check can be simplified a lot. Instead of checking against the _stext and _end symbols (which include code areas too) just check for the .data and .bss segments (since we check a data object). This can be done with the existing is_kernel_core_data() macro. In addition objects in the __initdata section can be checked with init_section_contains(), and is_kernel_rodata() allows keys to be in the _ro_after_init section. This partly reverts and simplifies commit |
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Dietmar Eggemann
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5d248bb39f |
torture: Add lock_torture writer_fifo module parameter
This commit adds a module parameter that causes the locktorture writer to run at real-time priority. To use it: insmod /lib/modules/torture.ko random_shuffle=1 insmod /lib/modules/locktorture.ko torture_type=mutex_lock rt_boost=1 rt_boost_factor=50 nested_locks=3 writer_fifo=1 ^^^^^^^^^^^^^ A predecessor to this patch has been helpful to uncover issues with the proxy-execution series. [ paulmck: Remove locktorture-specific code from kernel/torture.c. ] Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: kernel-team@android.com Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> [jstultz: Include header change to build, reword commit message] Signed-off-by: John Stultz <jstultz@google.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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Arnd Bergmann
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8874a414f8 |
x86/qspinlock-paravirt: Fix missing-prototype warning
__pv_queued_spin_unlock_slowpath() is defined in a header file as
a global function, and designed to be called from inline asm, but
there is no prototype visible in the definition:
kernel/locking/qspinlock_paravirt.h:493:1: error: no previous \
prototype for '__pv_queued_spin_unlock_slowpath' [-Werror=missing-prototypes]
Add this to the x86 header that contains the inline asm calling it,
and ensure this gets included before the definition, rather than
after it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230803082619.1369127-8-arnd@kernel.org
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Peter Zijlstra
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f7853c3424 |
locking/rtmutex: Fix task->pi_waiters integrity
Henry reported that rt_mutex_adjust_prio_check() has an ordering
problem and puts the lie to the comment in [7]. Sharing the sort key
between lock->waiters and owner->pi_waiters *does* create problems,
since unlike what the comment claims, holding [L] is insufficient.
Notably, consider:
A
/ \
M1 M2
| |
B C
That is, task A owns both M1 and M2, B and C block on them. In this
case a concurrent chain walk (B & C) will modify their resp. sort keys
in [7] while holding M1->wait_lock and M2->wait_lock. So holding [L]
is meaningless, they're different Ls.
This then gives rise to a race condition between [7] and [11], where
the requeue of pi_waiters will observe an inconsistent tree order.
B C
(holds M1->wait_lock, (holds M2->wait_lock,
holds B->pi_lock) holds A->pi_lock)
[7]
waiter_update_prio();
...
[8]
raw_spin_unlock(B->pi_lock);
...
[10]
raw_spin_lock(A->pi_lock);
[11]
rt_mutex_enqueue_pi();
// observes inconsistent A->pi_waiters
// tree order
Fixing this means either extending the range of the owner lock from
[10-13] to [6-13], with the immediate problem that this means [6-8]
hold both blocked and owner locks, or duplicating the sort key.
Since the locking in chain walk is horrible enough without having to
consider pi_lock nesting rules, duplicate the sort key instead.
By giving each tree their own sort key, the above race becomes
harmless, if C sees B at the old location, then B will correct things
(if they need correcting) when it walks up the chain and reaches A.
Fixes:
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Linus Torvalds
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77b1a7f7a0 |
- Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in
top-level directories. - Douglas Anderson has added a new "buddy" mode to the hardlockup detector. It permits the detector to work on architectures which cannot provide the required interrupts, by having CPUs periodically perform checks on other CPUs. - Zhen Lei has enhanced kexec's ability to support two crash regions. - Petr Mladek has done a lot of cleanup on the hard lockup detector's Kconfig entries. - And the usual bunch of singleton patches in various places. -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZJelTAAKCRDdBJ7gKXxA juDkAP0VXWynzkXoojdS/8e/hhi+htedmQ3v2dLZD+vBrctLhAEA7rcH58zAVoWa 2ejqO6wDrRGUC7JQcO9VEjT0nv73UwU= =F293 -----END PGP SIGNATURE----- Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-mm updates from Andrew Morton: - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level directories - Douglas Anderson has added a new "buddy" mode to the hardlockup detector. It permits the detector to work on architectures which cannot provide the required interrupts, by having CPUs periodically perform checks on other CPUs - Zhen Lei has enhanced kexec's ability to support two crash regions - Petr Mladek has done a lot of cleanup on the hard lockup detector's Kconfig entries - And the usual bunch of singleton patches in various places * tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits) kernel/time/posix-stubs.c: remove duplicated include ocfs2: remove redundant assignment to variable bit_off watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h devres: show which resource was invalid in __devm_ioremap_resource() watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64 watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h watchdog/hardlockup: make the config checks more straightforward watchdog/hardlockup: sort hardlockup detector related config values a logical way watchdog/hardlockup: move SMP barriers from common code to buddy code watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY watchdog/buddy: don't copy the cpumask in watchdog_next_cpu() watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog() watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy() watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick() watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe() watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails ... |
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Linus Torvalds
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bc6cb4d5bc |
Locking changes for v6.5:
- Introduce cmpxchg128() -- aka. the demise of cmpxchg_double().
The cmpxchg128() family of functions is basically & functionally
the same as cmpxchg_double(), but with a saner interface: instead
of a 6-parameter horror that forced u128 - u64/u64-halves layout
details on the interface and exposed users to complexity,
fragility & bugs, use a natural 3-parameter interface with u128 types.
- Restructure the generated atomic headers, and add
kerneldoc comments for all of the generic atomic{,64,_long}_t
operations. Generated definitions are much cleaner now,
and come with documentation.
- Implement lock_set_cmp_fn() on lockdep, for defining an ordering
when taking multiple locks of the same type. This gets rid of
one use of lockdep_set_novalidate_class() in the bcache code.
- Fix raw_cpu_generic_try_cmpxchg() bug due to an unintended
variable shadowing generating garbage code on Clang on certain
ARM builds.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Introduce cmpxchg128() -- aka. the demise of cmpxchg_double()
The cmpxchg128() family of functions is basically & functionally the
same as cmpxchg_double(), but with a saner interface.
Instead of a 6-parameter horror that forced u128 - u64/u64-halves
layout details on the interface and exposed users to complexity,
fragility & bugs, use a natural 3-parameter interface with u128
types.
- Restructure the generated atomic headers, and add kerneldoc comments
for all of the generic atomic{,64,_long}_t operations.
The generated definitions are much cleaner now, and come with
documentation.
- Implement lock_set_cmp_fn() on lockdep, for defining an ordering when
taking multiple locks of the same type.
This gets rid of one use of lockdep_set_novalidate_class() in the
bcache code.
- Fix raw_cpu_generic_try_cmpxchg() bug due to an unintended variable
shadowing generating garbage code on Clang on certain ARM builds.
* tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
locking/atomic: scripts: fix ${atomic}_dec_if_positive() kerneldoc
percpu: Fix self-assignment of __old in raw_cpu_generic_try_cmpxchg()
locking/atomic: treewide: delete arch_atomic_*() kerneldoc
locking/atomic: docs: Add atomic operations to the driver basic API documentation
locking/atomic: scripts: generate kerneldoc comments
docs: scripts: kernel-doc: accept bitwise negation like ~@var
locking/atomic: scripts: simplify raw_atomic*() definitions
locking/atomic: scripts: simplify raw_atomic_long*() definitions
locking/atomic: scripts: split pfx/name/sfx/order
locking/atomic: scripts: restructure fallback ifdeffery
locking/atomic: scripts: build raw_atomic_long*() directly
locking/atomic: treewide: use raw_atomic*_<op>()
locking/atomic: scripts: add trivial raw_atomic*_<op>()
locking/atomic: scripts: factor out order template generation
locking/atomic: scripts: remove leftover "${mult}"
locking/atomic: scripts: remove bogus order parameter
locking/atomic: xtensa: add preprocessor symbols
locking/atomic: x86: add preprocessor symbols
locking/atomic: sparc: add preprocessor symbols
locking/atomic: sh: add preprocessor symbols
...
|
||
|
Linus Torvalds
|
af96134dc8 |
RCU pull request for v6.5
This pull contains the following branches:
doc.2023.05.10a: Documentation updates
fixes.2023.05.11a: Miscellaneous fixes, perhaps most notably:
o Remove RCU_NONIDLE(). The new visibility of most of the idle
loop to RCU has obsoleted this API.
o Make the RCU_SOFTIRQ callback-invocation time limit also apply
to the rcuc kthreads that invoke callbacks for CONFIG_PREEMPT_RT.
o Add a jiffies-based callback-invocation time limit to handle
long-running callbacks. (The local_clock() function is only
invoked once per 32 callbacks due to its high overhead.)
o Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs,
which fixes a bug that can occur on systems with non-contiguous
CPU numbering.
kvfree.2023.05.10a: kvfree_rcu updates
o Eliminate the single-argument variant of k[v]free_rcu() now
that all uses have been converted to k[v]free_rcu_mightsleep().
o Add WARN_ON_ONCE() checks for k[v]free_rcu*() freeing callbacks
too soon. Yes, this is closing the barn door after the horse
has escaped, but Murphy says that there will be more horses.
nocb.2023.05.11a: Callback-offloading updates
o Fix a number of bugs involving the shrinker and lazy callbacks.
rcu-tasks.2023.05.10a: Tasks RCU updates
torture.2023.05.15a: Torture-test updates
rcu-urgent.2023.06.06a: Urgent SRCU fix (already pulled)
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Merge tag 'rcu.2023.06.22a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney:
"Documentation updates
Miscellaneous fixes, perhaps most notably:
- Remove RCU_NONIDLE(). The new visibility of most of the idle loop
to RCU has obsoleted this API.
- Make the RCU_SOFTIRQ callback-invocation time limit also apply to
the rcuc kthreads that invoke callbacks for CONFIG_PREEMPT_RT.
- Add a jiffies-based callback-invocation time limit to handle
long-running callbacks. (The local_clock() function is only invoked
once per 32 callbacks due to its high overhead.)
- Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs, which
fixes a bug that can occur on systems with non-contiguous CPU
numbering.
kvfree_rcu updates:
- Eliminate the single-argument variant of k[v]free_rcu() now that
all uses have been converted to k[v]free_rcu_mightsleep().
- Add WARN_ON_ONCE() checks for k[v]free_rcu*() freeing callbacks too
soon. Yes, this is closing the barn door after the horse has
escaped, but Murphy says that there will be more horses.
Callback-offloading updates:
- Fix a number of bugs involving the shrinker and lazy callbacks.
Tasks RCU updates
Torture-test updates"
* tag 'rcu.2023.06.22a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (32 commits)
torture: Remove duplicated argument -enable-kvm for ppc64
doc/rcutorture: Add description of rcutorture.stall_cpu_block
rcu/rcuscale: Stop kfree_scale_thread thread(s) after unloading rcuscale
rcu/rcuscale: Move rcu_scale_*() after kfree_scale_cleanup()
rcutorture: Correct name of use_softirq module parameter
locktorture: Add long_hold to adjust lock-hold delays
rcu/nocb: Make shrinker iterate only over NOCB CPUs
rcu-tasks: Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs
rcu: Make rcu_cpu_starting() rely on interrupts being disabled
rcu: Mark rcu_cpu_kthread() accesses to ->rcu_cpu_has_work
rcu: Mark additional concurrent load from ->cpu_no_qs.b.exp
rcu: Employ jiffies-based backstop to callback time limit
rcu: Check callback-invocation time limit for rcuc kthreads
rcu: Remove RCU_NONIDLE()
rcu: Add more RCU files to kernel-api.rst
rcu-tasks: Clarify the cblist_init_generic() function's pr_info() output
rcu-tasks: Avoid pr_info() with spin lock in cblist_init_generic()
rcu/nocb: Recheck lazy callbacks under the ->nocb_lock from shrinker
rcu/nocb: Fix shrinker race against callback enqueuer
rcu/nocb: Protect lazy shrinker against concurrent (de-)offloading
...
|
||
|
Arnd Bergmann
|
ff7138813a |
locking: add lockevent_read() prototype
lockevent_read() has a __weak definition and the only caller in kernel/locking/lock_events.c, plus a strong definition in qspinlock_stat.h that overrides it, but no other declaration. This causes a W=1 warning: kernel/locking/lock_events.c:61:16: error: no previous prototype for 'lockevent_read' [-Werror=missing-prototypes] Add shared prototype to avoid the warnings. Link: https://lkml.kernel.org/r/20230517131102.934196-7-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Eric Paris <eparis@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Linus Torvalds
|
d8f14b84fe |
Two fixes for debugobjects:
- Prevent that the allocation path wakes up kswapd. That's a long
standing issue due to the GFP_ATOMIC allocation flag. As debug objects
can be invoked from pretty much any context waking kswapd can end up
in arbitrary lock chains versus the waitqueue lock.
- Correct the explicit lockdep wait-type violation in
debug_object_fill_pool().
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Merge tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull debugobjects fixes from Thomas Gleixner:
"Two fixes for debugobjects:
- Prevent the allocation path from waking up kswapd.
That's a long standing issue due to the GFP_ATOMIC allocation flag.
As debug objects can be invoked from pretty much any context waking
kswapd can end up in arbitrary lock chains versus the waitqueue
lock
- Correct the explicit lockdep wait-type violation in
debug_object_fill_pool()"
* tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debugobjects: Don't wake up kswapd from fill_pool()
debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
|
||
Kent Overstreet
|
eb1cfd09f7 |
lockdep: Add lock_set_cmp_fn() annotation
This implements a new interface to lockdep, lock_set_cmp_fn(), for defining a custom ordering when taking multiple locks of the same class. This is an alternative to subclasses, but can not fully replace them since subclasses allow lock hierarchies with other clasees inter-twined, while this relies on pure class nesting. Specifically, if A is our nesting class then: A/0 <- B <- A/1 Would be a valid lock order with subclasses (each subclass really is a full class from the validation PoV) but not with this annotation, which requires all nesting to be consecutive. Example output: | ============================================ | WARNING: possible recursive locking detected | 6.2.0-rc8-00003-g7d81e591ca6a-dirty #15 Not tainted | -------------------------------------------- | kworker/14:3/938 is trying to acquire lock: | ffff8880143218c8 (&b->lock l=0 0:2803368){++++}-{3:3}, at: bch_btree_node_get.part.0+0x81/0x2b0 | | but task is already holding lock: | ffff8880143de8c8 (&b->lock l=1 1048575:9223372036854775807){++++}-{3:3}, at: __bch_btree_map_nodes+0xea/0x1e0 | and the lock comparison function returns 1: | | other info that might help us debug this: | Possible unsafe locking scenario: | | CPU0 | ---- | lock(&b->lock l=1 1048575:9223372036854775807); | lock(&b->lock l=0 0:2803368); | | *** DEADLOCK *** | | May be due to missing lock nesting notation | | 3 locks held by kworker/14:3/938: | #0: ffff888005ea9d38 ((wq_completion)bcache){+.+.}-{0:0}, at: process_one_work+0x1ec/0x530 | #1: ffff8880098c3e70 ((work_completion)(&cl->work)#3){+.+.}-{0:0}, at: process_one_work+0x1ec/0x530 | #2: ffff8880143de8c8 (&b->lock l=1 1048575:9223372036854775807){++++}-{3:3}, at: __bch_btree_map_nodes+0xea/0x1e0 [peterz: extended changelog] Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230509195847.1745548-1-kent.overstreet@linux.dev |
||
Paul E. McKenney
|
f8619c300f |
locktorture: Add long_hold to adjust lock-hold delays
This commit adds a long_hold module parameter to allow testing diagnostics for excessive lock-hold times. Also adjust torture_param() invocations for longer line length while in the area. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> |
||
|
John Stultz
|
92cc5d00a4 |
locking/rwsem: Add __always_inline annotation to __down_read_common() and inlined callers
Apparently despite it being marked inline, the compiler
may not inline __down_read_common() which makes it difficult
to identify the cause of lock contention, as the blocked
function in traceevents will always be listed as
__down_read_common().
So this patch adds __always_inline annotation to the common
function (as well as the inlined helper callers) to force it to
be inlined so the blocking function will be listed (via Wchan)
in traceevents.
Fixes:
|
||
|
Linus Torvalds
|
b115d85a95 |
Locking changes in v6.4:
- Introduce local{,64}_try_cmpxchg() - a slightly more optimal
primitive, which will be used in perf events ring-buffer code.
- Simplify/modify rwsems on PREEMPT_RT, to address writer starvation.
- Misc cleanups/fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Introduce local{,64}_try_cmpxchg() - a slightly more optimal
primitive, which will be used in perf events ring-buffer code
- Simplify/modify rwsems on PREEMPT_RT, to address writer starvation
- Misc cleanups/fixes
* tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/atomic: Correct (cmp)xchg() instrumentation
locking/x86: Define arch_try_cmpxchg_local()
locking/arch: Wire up local_try_cmpxchg()
locking/generic: Wire up local{,64}_try_cmpxchg()
locking/atomic: Add generic try_cmpxchg{,64}_local() support
locking/rwbase: Mitigate indefinite writer starvation
locking/arch: Rename all internal __xchg() names to __arch_xchg()
|
||
|
Peter Zijlstra
|
0cce06ba85 |
debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
There is an explicit wait-type violation in debug_object_fill_pool() for PREEMPT_RT=n kernels which allows them to more easily fill the object pool and reduce the chance of allocation failures. Lockdep's wait-type checks are designed to check the PREEMPT_RT locking rules even for PREEMPT_RT=n kernels and object to this, so create a lockdep annotation to allow this to stand. Specifically, create a 'lock' type that overrides the inner wait-type while it is held -- allowing one to temporarily raise it, such that the violation is hidden. Reported-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Qi Zheng <zhengqi.arch@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Qi Zheng <zhengqi.arch@bytedance.com> Link: https://lkml.kernel.org/r/20230429100614.GA1489784@hirez.programming.kicks-ass.net |
||
|
Sebastian Andrzej Siewior
|
286deb7ec0 |
locking/rwbase: Mitigate indefinite writer starvation
On PREEMPT_RT, rw_semaphore and rwlock_t locks are unfair to writers. Readers can indefinitely acquire the lock unless the writer fully acquired the lock, which might never happen if there is always a reader in the critical section owning the lock. Mel Gorman reported that since LTP-20220121 the dio_truncate test case went from having 1 reader to having 16 readers and that number of readers is sufficient to prevent the down_write ever succeeding while readers exist. Eventually the test is killed after 30 minutes as a failure. Mel proposed a timeout to limit how long a writer can be blocked until the reader is forced into the slowpath. Thomas argued that there is no added value by providing this timeout. From a PREEMPT_RT point of view, there are no critical rw_semaphore or rwlock_t locks left where the reader must be preferred. Mitigate indefinite writer starvation by forcing the READER into the slowpath once the WRITER attempts to acquire the lock. Reported-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lore.kernel.org/877cwbq4cq.ffs@tglx Link: https://lore.kernel.org/r/20230321161140.HMcQEhHb@linutronix.de Cc: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
5dfb75e842 |
RCU Changes for 6.4:
o MAINTAINERS files additions and changes.
o Fix hotplug warning in nohz code.
o Tick dependency changes by Zqiang.
o Lazy-RCU shrinker fixes by Zqiang.
o rcu-tasks stall reporting improvements by Neeraj.
o Initial changes for renaming of k[v]free_rcu() to its new k[v]free_rcu_mightsleep()
name for robustness.
o Documentation Updates:
o Significant changes to srcu_struct size.
o Deadlock detection for srcu_read_lock() vs synchronize_srcu() from Boqun.
o rcutorture and rcu-related tool, which are targeted for v6.4 from Boqun's tree.
o Other misc changes.
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Merge tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux
Pull RCU updates from Joel Fernandes:
- Updates and additions to MAINTAINERS files, with Boqun being added to
the RCU entry and Zqiang being added as an RCU reviewer.
I have also transitioned from reviewer to maintainer; however, Paul
will be taking over sending RCU pull-requests for the next merge
window.
- Resolution of hotplug warning in nohz code, achieved by fixing
cpu_is_hotpluggable() through interaction with the nohz subsystem.
Tick dependency modifications by Zqiang, focusing on fixing usage of
the TICK_DEP_BIT_RCU_EXP bitmask.
- Avoid needless calls to the rcu-lazy shrinker for CONFIG_RCU_LAZY=n
kernels, fixed by Zqiang.
- Improvements to rcu-tasks stall reporting by Neeraj.
- Initial renaming of k[v]free_rcu() to k[v]free_rcu_mightsleep() for
increased robustness, affecting several components like mac802154,
drbd, vmw_vmci, tracing, and more.
A report by Eric Dumazet showed that the API could be unknowingly
used in an atomic context, so we'd rather make sure they know what
they're asking for by being explicit:
https://lore.kernel.org/all/20221202052847.2623997-1-edumazet@google.com/
- Documentation updates, including corrections to spelling,
clarifications in comments, and improvements to the srcu_size_state
comments.
- Better srcu_struct cache locality for readers, by adjusting the size
of srcu_struct in support of SRCU usage by Christoph Hellwig.
- Teach lockdep to detect deadlocks between srcu_read_lock() vs
synchronize_srcu() contributed by Boqun.
Previously lockdep could not detect such deadlocks, now it can.
- Integration of rcutorture and rcu-related tools, targeted for v6.4
from Boqun's tree, featuring new SRCU deadlock scenarios, test_nmis
module parameter, and more
- Miscellaneous changes, various code cleanups and comment improvements
* tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux: (71 commits)
checkpatch: Error out if deprecated RCU API used
mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()
rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep()
ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/mlx5: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
lib/test_vmalloc.c: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
tracing: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
misc: vmw_vmci: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
drbd: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
rcu-tasks: Report stalls during synchronize_srcu() in rcu_tasks_postscan()
rcu: Permit start_poll_synchronize_rcu_expedited() to be invoked early
rcu: Remove never-set needwake assignment from rcu_report_qs_rdp()
rcu: Register rcu-lazy shrinker only for CONFIG_RCU_LAZY=y kernels
rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
rcu: Fix set/clear TICK_DEP_BIT_RCU_EXP bitmask race
rcu/trace: use strscpy() to instead of strncpy()
tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
...
|
||
Boqun Feng
|
0471db447c |
locking/lockdep: Improve the deadlock scenario print for sync and read lock
Lock scenario print is always a weak spot of lockdep splats. Improvement can be made if we rework the dependency search and the error printing. However without touching the graph search, we can improve a little for the circular deadlock case, since we have the to-be-added lock dependency, and know whether these two locks are read/write/sync. In order to know whether a held_lock is sync or not, a bit was "stolen" from ->references, which reduce our limit for the same lock class nesting from 2^12 to 2^11, and it should still be good enough. Besides, since we now have bit in held_lock for sync, we don't need the "hardirqoffs being 1" trick, and also we can avoid the __lock_release() if we jump out of __lock_acquire() before the held_lock stored. With these changes, a deadlock case evolved with read lock and sync gets a better print-out from: [...] Possible unsafe locking scenario: [...] [...] CPU0 CPU1 [...] ---- ---- [...] lock(srcuA); [...] lock(srcuB); [...] lock(srcuA); [...] lock(srcuB); to [...] Possible unsafe locking scenario: [...] [...] CPU0 CPU1 [...] ---- ---- [...] rlock(srcuA); [...] lock(srcuB); [...] lock(srcuA); [...] sync(srcuB); Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> |
||
|
Boqun Feng
|
60a1a64ec0 |
locking: Reduce the number of locks in ww_mutex stress tests
The stress test in test_ww_mutex_init() uses 4095 locks since lockdep::reference has 12 bits, and since we are going to reduce it to 11 bits to support lock_sync(), and 2047 is still a reasonable number of the max nesting level for locks, so adjust the test. Reported-by: kernel test robot <oliver.sang@intel.com> Link: https://lore.kernel.org/oe-lkp/202302011445.9d99dae2-oliver.sang@intel.com Tested-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> |
||
|
Boqun Feng
|
2f1f043e7b |
locking/lockdep: Introduce lock_sync()
Currently, functions like synchronize_srcu() do not have lockdep
annotations resembling those of other write-side locking primitives.
Such annotations might look as follows:
lock_acquire();
lock_release();
Such annotations would tell lockdep that synchronize_srcu() acts like
an empty critical section that waits for other (read-side) critical
sections to finish. This would definitely catch some deadlock, but
as pointed out by Paul Mckenney [1], this could also introduce false
positives because of irq-safe/unsafe detection. Of course, there are
tricks could help with this:
might_sleep(); // Existing statement in __synchronize_srcu().
if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
local_irq_disable();
lock_acquire();
lock_release();
local_irq_enable();
}
But it would be better for lockdep to provide a separate annonation for
functions like synchronize_srcu(), so that people won't need to repeat
the ugly tricks above.
Therefore introduce lock_sync(), which is simply an lock+unlock
pair with no irq safe/unsafe deadlock check. This works because the
to-be-annontated functions do not create real critical sections, and
there is therefore no way that irq can create extra dependencies.
[1]: https://lore.kernel.org/lkml/20180412021233.ewncg5jjuzjw3x62@tardis/
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ boqun: Fix typos reported by Davidlohr Bueso and Paul E. Mckenney ]
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
|
||
Zqiang
|
5d65cf6ae6 |
locktorture: Add raw_spinlock* torture tests for PREEMPT_RT kernels
In PREEMPT_RT kernels, both spin_lock() and spin_lock_irq() are converted to sleepable rt_spin_lock(). This means that the interrupt related suffixes for spin_lock/unlock(_irq, irqsave/irqrestore) do not affect the CPU's interrupt state. This commit therefore adds raw spin-lock torture tests. This in turn permits pure spin locks to be tested in PREEMPT_RT kernels. Suggested-by: Paul E. McKenney <paulmck@kernel.org> Suggested-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Zqiang <qiang1.zhang@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
John Stultz
|
45bcf0bd8c |
locktorture: With nested locks, occasionally skip main lock
If we're using nested locking to stress things, occasionally skip taking the main lock, so that we can get some different contention patterns between the writers (to hopefully get two disjoint blocked trees) Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: kernel-team@android.com Co-developed-by: Connor O'Brien <connoro@google.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
John Stultz
|
ae4823e427 |
locktorture: Add nested locking to rtmutex torture tests
This patch adds randomized nested locking to the rtmutex torture tests. Additionally it adds LOCK09 config files for testing rtmutexes with nested locking. Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: kernel-team@android.com Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Co-developed-by: Connor O'Brien <connoro@google.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
John Stultz
|
3e5aeaf534 |
locktorture: Add nested locking to mutex torture tests
This patch adds randomized nested locking to the mutex torture tests, as well as new LOCK08 config files for testing mutexes with nested locking Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: kernel-team@android.com Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Co-developed-by: Connor O'Brien <connoro@google.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
John Stultz
|
b63343207d |
locktorture: Add nested_[un]lock() hooks and nlocks parameter
In order to extend locktorture to support lock nesting, add nested_lock() and nested_unlock() hooks to the torture ops. These take a 32bit lockset mask which is generated at random, so some number of locks will be taken before the main lock is taken and released afterwards. Additionally, add nested_locks module parameter to allow specifying the number of nested locks to be used. This has been helpful to uncover issues in the proxy-exec series development. This was inspired by locktorture extensions originally implemented by Connor O'Brien, for stress testing the proxy-execution series: https://lore.kernel.org/lkml/20221003214501.2050087-12-connoro@google.com/ Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: kernel-team@android.com Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Co-developed-by: Connor O'Brien <connoro@google.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
Linus Torvalds
|
8cc01d43f8 |
RCU pull request for v6.3
This pull request contains the following branches:
doc.2023.01.05a: Documentation updates.
fixes.2023.01.23a: Miscellaneous fixes, perhaps most notably:
o Throttling callback invocation based on the number of callbacks
that are now ready to invoke instead of on the total number
of callbacks.
o Several patches that suppress false-positive boot-time
diagnostics, for example, due to lockdep not yet being
initialized.
o Make expedited RCU CPU stall warnings dump stacks of any tasks
that are blocking the stalled grace period. (Normal RCU CPU
stall warnings have doen this for mnay years.)
o Lazy-callback fixes to avoid delays during boot, suspend, and
resume. (Note that lazy callbacks must be explicitly enabled,
so this should not (yet) affect production use cases.)
kvfree.2023.01.03a: Cause kfree_rcu() and friends to take advantage of
polled grace periods, thus reducing memory footprint by almost
two orders of magnitude, admittedly on a microbenchmark.
This series also begins the transition from kfree_rcu(p) to
kfree_rcu_mightsleep(p). This transition was motivated by bugs
where kfree_rcu(p), which can block, was typed instead of the
intended kfree_rcu(p, rh).
srcu.2023.01.03a: SRCU updates, perhaps most notably fixing a bug that
causes SRCU to fail when booted on a system with a non-zero boot
CPU. This surprising situation actually happens for kdump kernels
on the powerpc architecture. It also adds an srcu_down_read()
and srcu_up_read(), which act like srcu_read_lock() and
srcu_read_unlock(), but allow an SRCU read-side critical section
to be handed off from one task to another.
srcu-always.2023.02.02a: Cleans up the now-useless SRCU Kconfig option.
There are a few more commits that are not yet acked or pulled
into maintainer trees, and these will be in a pull request for
a later merge window.
tasks.2023.01.03a: RCU-tasks updates, perhaps most notably these fixes:
o A strange interaction between PID-namespace unshare and the
RCU-tasks grace period that results in a low-probability but
very real hang.
o A race between an RCU tasks rude grace period on a single-CPU
system and CPU-hotplug addition of the second CPU that can result
in a too-short grace period.
o A race between shrinking RCU tasks down to a single callback list
and queuing a new callback to some other CPU, but where that
queuing is delayed for more than an RCU grace period. This can
result in that callback being stranded on the non-boot CPU.
torture.2023.01.05a: Torture-test updates and fixes.
torturescript.2023.01.03a: Torture-test scripting updates and fixes.
stall.2023.01.09a: Provide additional RCU CPU stall-warning information
in kernels built with CONFIG_RCU_CPU_STALL_CPUTIME=y, and
restore the full five-minute timeout limit for expedited RCU
CPU stall warnings.
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Merge tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney:
- Documentation updates
- Miscellaneous fixes, perhaps most notably:
- Throttling callback invocation based on the number of callbacks
that are now ready to invoke instead of on the total number of
callbacks
- Several patches that suppress false-positive boot-time
diagnostics, for example, due to lockdep not yet being
initialized
- Make expedited RCU CPU stall warnings dump stacks of any tasks
that are blocking the stalled grace period. (Normal RCU CPU
stall warnings have done this for many years)
- Lazy-callback fixes to avoid delays during boot, suspend, and
resume. (Note that lazy callbacks must be explicitly enabled, so
this should not (yet) affect production use cases)
- Make kfree_rcu() and friends take advantage of polled grace periods,
thus reducing memory footprint by almost two orders of magnitude,
admittedly on a microbenchmark
This also begins the transition from kfree_rcu(p) to
kfree_rcu_mightsleep(p). This transition was motivated by bugs where
kfree_rcu(p), which can block, was typed instead of the intended
kfree_rcu(p, rh)
- SRCU updates, perhaps most notably fixing a bug that causes SRCU to
fail when booted on a system with a non-zero boot CPU. This
surprising situation actually happens for kdump kernels on the
powerpc architecture
This also adds an srcu_down_read() and srcu_up_read(), which act like
srcu_read_lock() and srcu_read_unlock(), but allow an SRCU read-side
critical section to be handed off from one task to another
- Clean up the now-useless SRCU Kconfig option
There are a few more commits that are not yet acked or pulled into
maintainer trees, and these will be in a pull request for a later
merge window
- RCU-tasks updates, perhaps most notably these fixes:
- A strange interaction between PID-namespace unshare and the
RCU-tasks grace period that results in a low-probability but
very real hang
- A race between an RCU tasks rude grace period on a single-CPU
system and CPU-hotplug addition of the second CPU that can
result in a too-short grace period
- A race between shrinking RCU tasks down to a single callback
list and queuing a new callback to some other CPU, but where
that queuing is delayed for more than an RCU grace period. This
can result in that callback being stranded on the non-boot CPU
- Torture-test updates and fixes
- Torture-test scripting updates and fixes
- Provide additional RCU CPU stall-warning information in kernels built
with CONFIG_RCU_CPU_STALL_CPUTIME=y, and restore the full five-minute
timeout limit for expedited RCU CPU stall warnings
* tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (80 commits)
rcu/kvfree: Add kvfree_rcu_mightsleep() and kfree_rcu_mightsleep()
kernel/notifier: Remove CONFIG_SRCU
init: Remove "select SRCU"
fs/quota: Remove "select SRCU"
fs/notify: Remove "select SRCU"
fs/btrfs: Remove "select SRCU"
fs: Remove CONFIG_SRCU
drivers/pci/controller: Remove "select SRCU"
drivers/net: Remove "select SRCU"
drivers/md: Remove "select SRCU"
drivers/hwtracing/stm: Remove "select SRCU"
drivers/dax: Remove "select SRCU"
drivers/base: Remove CONFIG_SRCU
rcu: Disable laziness if lazy-tracking says so
rcu: Track laziness during boot and suspend
rcu: Remove redundant call to rcu_boost_kthread_setaffinity()
rcu: Allow up to five minutes expedited RCU CPU stall-warning timeouts
rcu: Align the output of RCU CPU stall warning messages
rcu: Add RCU stall diagnosis information
sched: Add helper nr_context_switches_cpu()
...
|
||
|
Linus Torvalds
|
1f2d9ffc7a |
Scheduler updates in this cycle are:
- Improve the scalability of the CFS bandwidth unthrottling logic
with large number of CPUs.
- Fix & rework various cpuidle routines, simplify interaction with
the generic scheduler code. Add __cpuidle methods as noinstr to
objtool's noinstr detection and fix boatloads of cpuidle bugs & quirks.
- Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS,
to query previously issued registrations.
- Limit scheduler slice duration to the sysctl_sched_latency period,
to improve scheduling granularity with a large number of SCHED_IDLE
tasks.
- Debuggability enhancement on sys_exit(): warn about disabled IRQs,
but also enable them to prevent a cascade of followup problems and
repeat warnings.
- Fix the rescheduling logic in prio_changed_dl().
- Micro-optimize cpufreq and sched-util methods.
- Micro-optimize ttwu_runnable()
- Micro-optimize the idle-scanning in update_numa_stats(),
select_idle_capacity() and steal_cookie_task().
- Update the RSEQ code & self-tests
- Constify various scheduler methods
- Remove unused methods
- Refine __init tags
- Documentation updates
- ... Misc other cleanups, fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Improve the scalability of the CFS bandwidth unthrottling logic with
large number of CPUs.
- Fix & rework various cpuidle routines, simplify interaction with the
generic scheduler code. Add __cpuidle methods as noinstr to objtool's
noinstr detection and fix boatloads of cpuidle bugs & quirks.
- Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS, to query
previously issued registrations.
- Limit scheduler slice duration to the sysctl_sched_latency period, to
improve scheduling granularity with a large number of SCHED_IDLE
tasks.
- Debuggability enhancement on sys_exit(): warn about disabled IRQs,
but also enable them to prevent a cascade of followup problems and
repeat warnings.
- Fix the rescheduling logic in prio_changed_dl().
- Micro-optimize cpufreq and sched-util methods.
- Micro-optimize ttwu_runnable()
- Micro-optimize the idle-scanning in update_numa_stats(),
select_idle_capacity() and steal_cookie_task().
- Update the RSEQ code & self-tests
- Constify various scheduler methods
- Remove unused methods
- Refine __init tags
- Documentation updates
- Misc other cleanups, fixes
* tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits)
sched/rt: pick_next_rt_entity(): check list_entry
sched/deadline: Add more reschedule cases to prio_changed_dl()
sched/fair: sanitize vruntime of entity being placed
sched/fair: Remove capacity inversion detection
sched/fair: unlink misfit task from cpu overutilized
objtool: mem*() are not uaccess safe
cpuidle: Fix poll_idle() noinstr annotation
sched/clock: Make local_clock() noinstr
sched/clock/x86: Mark sched_clock() noinstr
x86/pvclock: Improve atomic update of last_value in pvclock_clocksource_read()
x86/atomics: Always inline arch_atomic64*()
cpuidle: tracing, preempt: Squash _rcuidle tracing
cpuidle: tracing: Warn about !rcu_is_watching()
cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
cpuidle: drivers: firmware: psci: Dont instrument suspend code
KVM: selftests: Fix build of rseq test
exit: Detect and fix irq disabled state in oops
cpuidle, arm64: Fix the ARM64 cpuidle logic
cpuidle: mvebu: Fix duplicate flags assignment
sched/fair: Limit sched slice duration
...
|
||
|
Linus Torvalds
|
6e649d0856 |
Updates for this cycle were:
- rwsem micro-optimizations
- spinlock micro-optimizations
- cleanups, simplifications
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- rwsem micro-optimizations
- spinlock micro-optimizations
- cleanups, simplifications
* tag 'locking-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
vduse: Remove include of rwlock.h
locking/lockdep: Remove lockdep_init_map_crosslock.
x86/ACPI/boot: Use try_cmpxchg() in __acpi_{acquire,release}_global_lock()
x86/PAT: Use try_cmpxchg() in set_page_memtype()
locking/rwsem: Disable preemption in all down_write*() and up_write() code paths
locking/rwsem: Disable preemption in all down_read*() and up_read() code paths
locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath
locking/qspinlock: Micro-optimize pending state waiting for unlock
|
||
Wander Lairson Costa
|
db370a8b9f |
rtmutex: Ensure that the top waiter is always woken up
Let L1 and L2 be two spinlocks.
Let T1 be a task holding L1 and blocked on L2. T1, currently, is the top
waiter of L2.
Let T2 be the task holding L2.
Let T3 be a task trying to acquire L1.
The following events will lead to a state in which the wait queue of L2
isn't empty, but no task actually holds the lock.
T1 T2 T3
== == ==
spin_lock(L1)
| raw_spin_lock(L1->wait_lock)
| rtlock_slowlock_locked(L1)
| | task_blocks_on_rt_mutex(L1, T3)
| | | orig_waiter->lock = L1
| | | orig_waiter->task = T3
| | | raw_spin_unlock(L1->wait_lock)
| | | rt_mutex_adjust_prio_chain(T1, L1, L2, orig_waiter, T3)
spin_unlock(L2) | | | |
| rt_mutex_slowunlock(L2) | | | |
| | raw_spin_lock(L2->wait_lock) | | | |
| | wakeup(T1) | | | |
| | raw_spin_unlock(L2->wait_lock) | | | |
| | | | waiter = T1->pi_blocked_on
| | | | waiter == rt_mutex_top_waiter(L2)
| | | | waiter->task == T1
| | | | raw_spin_lock(L2->wait_lock)
| | | | dequeue(L2, waiter)
| | | | update_prio(waiter, T1)
| | | | enqueue(L2, waiter)
| | | | waiter != rt_mutex_top_waiter(L2)
| | | | L2->owner == NULL
| | | | wakeup(T1)
| | | | raw_spin_unlock(L2->wait_lock)
T1 wakes up
T1 != top_waiter(L2)
schedule_rtlock()
If the deadline of T1 is updated before the call to update_prio(), and the
new deadline is greater than the deadline of the second top waiter, then
after the requeue, T1 is no longer the top waiter, and the wrong task is
woken up which will then go back to sleep because it is not the top waiter.
This can be reproduced in PREEMPT_RT with stress-ng:
while true; do
stress-ng --sched deadline --sched-period 1000000000 \
--sched-runtime 800000000 --sched-deadline \
1000000000 --mmapfork 23 -t 20
done
A similar issue was pointed out by Thomas versus the cases where the top
waiter drops out early due to a signal or timeout, which is a general issue
for all regular rtmutex use cases, e.g. futex.
The problematic code is in rt_mutex_adjust_prio_chain():
// Save the top waiter before dequeue/enqueue
prerequeue_top_waiter = rt_mutex_top_waiter(lock);
rt_mutex_dequeue(lock, waiter);
waiter_update_prio(waiter, task);
rt_mutex_enqueue(lock, waiter);
// Lock has no owner?
if (!rt_mutex_owner(lock)) {
// Top waiter changed
----> if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
----> wake_up_state(waiter->task, waiter->wake_state);
This only takes the case into account where @waiter is the new top waiter
due to the requeue operation.
But it fails to handle the case where @waiter is not longer the top
waiter due to the requeue operation.
Ensure that the new top waiter is woken up so in all cases so it can take
over the ownerless lock.
[ tglx: Amend changelog, add Fixes tag ]
Fixes:
|
||
|
Peter Zijlstra
|
5a5d7e9bad |
cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
In order to avoid WARN/BUG from generating nested or even recursive warnings, force rcu_is_watching() true during WARN/lockdep_rcu_suspicious(). Notably things like unwinding the stack can trigger rcu_dereference() warnings, which then triggers more unwinding which then triggers more warnings etc.. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230126151323.408156109@infradead.org |
||
Waiman Long
|
1d61659ced |
locking/rwsem: Disable preemption in all down_write*() and up_write() code paths
The previous patch has disabled preemption in all the down_read() and
up_read() code paths. For symmetry, this patch extends commit:
|
||
|
Waiman Long
|
3f5245538a |
locking/rwsem: Disable preemption in all down_read*() and up_read() code paths
Commit: |
||
|
Waiman Long
|
b613c7f314 |
locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath
A non-first waiter can potentially spin in the for loop of
rwsem_down_write_slowpath() without sleeping but fail to acquire the
lock even if the rwsem is free if the following sequence happens:
Non-first RT waiter First waiter Lock holder
------------------- ------------ -----------
Acquire wait_lock
rwsem_try_write_lock():
Set handoff bit if RT or
wait too long
Set waiter->handoff_set
Release wait_lock
Acquire wait_lock
Inherit waiter->handoff_set
Release wait_lock
Clear owner
Release lock
if (waiter.handoff_set) {
rwsem_spin_on_owner(();
if (OWNER_NULL)
goto trylock_again;
}
trylock_again:
Acquire wait_lock
rwsem_try_write_lock():
if (first->handoff_set && (waiter != first))
return false;
Release wait_lock
A non-first waiter cannot really acquire the rwsem even if it mistakenly
believes that it can spin on OWNER_NULL value. If that waiter happens
to be an RT task running on the same CPU as the first waiter, it can
block the first waiter from acquiring the rwsem leading to live lock.
Fix this problem by making sure that a non-first waiter cannot spin in
the slowpath loop without sleeping.
Fixes:
|
||
Joel Fernandes (Google)
|
c24501b240 |
locktorture: Make the rt_boost factor a tunable
The rt boosting in locktorture has a factor variable s currently large enough that boosting only happens once every minute or so. Add a tunable to reduce the factor so that boosting happens more often, to test paths and arrive at failure modes earlier. With this change, I can set the factor to like 50 and have the boosting happens every 10 seconds or so. Tested with boot parameters: locktorture.torture_type=mutex_lock locktorture.onoff_interval=1 locktorture.nwriters_stress=8 locktorture.stutter=0 locktorture.rt_boost=1 locktorture.rt_boost_factor=50 locktorture.nlocks=3 Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
Joel Fernandes (Google)
|
e01f3a1a58 |
locktorture: Allow non-rtmutex lock types to be boosted
Currently RT boosting is only done for rtmutex_lock, however with proxy execution, we also have the mutex_lock participating in priorities. To exercise the testing better, add RT boosting to other lock testing types as well, using a new knob (rt_boost). Tested with boot parameters: locktorture.torture_type=mutex_lock locktorture.onoff_interval=1 locktorture.nwriters_stress=8 locktorture.stutter=0 locktorture.rt_boost=1 locktorture.rt_boost_factor=1 locktorture.nlocks=3 Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
Guo Ren
|
4282494a20 |
locking/qspinlock: Micro-optimize pending state waiting for unlock
When we're pending, we only care about lock value. The xchg_tail wouldn't affect the pending state. That means the hardware thread could stay in a sleep state and leaves the rest execution units' resources of pipeline to other hardware threads. This situation is the SMT scenarios in the same core. Not an entering low-power state situation. Of course, the granularity between cores is "cacheline", but the granularity between SMT hw threads of the same core could be "byte" which internal LSU handles. For example, when a hw-thread yields the resources of the core to other hw-threads, this patch could help the hw-thread stay in the sleep state and prevent it from being woken up by other hw-threads xchg_tail. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/20230105021952.3090070-1-guoren@kernel.org Cc: Peter Zijlstra <peterz@infradead.org> |
||
|
Linus Torvalds
|
95d248d16f |
- Prevent the leaking of a debug timer in futex_waitv()
- A preempt-RT mutex locking fix, adding the proper acquire semantics -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmOxn1cACgkQEsHwGGHe VUp+AQ/9GilVlaWqloC+sDK/7qTLfmQjR/XwQPii2pMBUO1oRFT7mG+dG7lKNpRL WCLTVIrzG528ORJytvMGuqx+CqenuTGPFI9rtizxdtRlNZyiS33hvlaGBPY7XYY7 G2qugGKuZ7WVKZpq6szPwnrMuWjdsd+XOO+NE3h/5kI2T7ZukmlXl9/EtVii7+y3 LGVjMhN+R0XCMCPSSPtFx5eUGalemPnGSBcX/Qb4zG1MphSPURFKHEQmWHZzgrkg 6fmqx773u2mquxTYeEy0FDLjOYFEHlzDFgRtIDBaziHIxjzO/5r09m8RDF2mXetW W/pf/Iduh2TZWwJDngmUi0JxqOzz0l8T/6vSCuArYWkjb+0zDOPHuCYwif2iHAQo pMn+O5nAtLMZhdk+yjTs4abQ11q9owLh0nGps4A2SKgJIH0mL2BICwRotzuV1sxf CGnoOxIxZuZGq8xMoHp6sJ8e4RnJHBAt7PKrCsLTkPAjKjgmBpqshVav//kyCFeY 2R4rgRY/a42Z86uNSysVnxxkop4vRgTZ3l7TijzyeIbycI7v9WMADk0TKTDgsMbL nEnlZPWXJGYNXH71ZPV5TPgidHfiO68sVKerXWRrWRLyGHhY2TC67Lz29vTAlbMK NdOM6pO0DkaKSLxEJ6qso819ePnRA/2O5B7xU/Ll7vONjCpHlFw= =9LHF -----END PGP SIGNATURE----- Merge tag 'locking_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Borislav Petkov: - Prevent the leaking of a debug timer in futex_waitv() - A preempt-RT mutex locking fix, adding the proper acquire semantics * tag 'locking_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Fix futex_waitv() hrtimer debug object leak on kcalloc error rtmutex: Add acquire semantics for rtmutex lock acquisition slow path |
||
|
Linus Torvalds
|
e2ca6ba6ba |
MM patches for 6.2-rc1.
- More userfaultfs work from Peter Xu. - Several convert-to-folios series from Sidhartha Kumar and Huang Ying. - Some filemap cleanups from Vishal Moola. - David Hildenbrand added the ability to selftest anon memory COW handling. - Some cpuset simplifications from Liu Shixin. - Addition of vmalloc tracing support by Uladzislau Rezki. - Some pagecache folioifications and simplifications from Matthew Wilcox. - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it. - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series shold have been in the non-MM tree, my bad. - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages. - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages. - Peter Xu utilized the PTE marker code for handling swapin errors. - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient. - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand. - zram support for multiple compression streams from Sergey Senozhatsky. - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway. - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations. - Vishal Moola removed the try_to_release_page() wrapper. - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache. - David Hildenbrand did some cleanup and repair work on KSM COW breaking. - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend. - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range(). - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen. - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect. - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages(). - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting. - David Hildenbrand has fixed some of our MM selftests for 32-bit machines. - Many singleton patches, as usual. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY5j6ZwAKCRDdBJ7gKXxA jkDYAP9qNeVqp9iuHjZNTqzMXkfmJPsw2kmy2P+VdzYVuQRcJgEAgoV9d7oMq4ml CodAgiA51qwzId3GRytIo/tfWZSezgA= =d19R -----END PGP SIGNATURE----- Merge tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - More userfaultfs work from Peter Xu - Several convert-to-folios series from Sidhartha Kumar and Huang Ying - Some filemap cleanups from Vishal Moola - David Hildenbrand added the ability to selftest anon memory COW handling - Some cpuset simplifications from Liu Shixin - Addition of vmalloc tracing support by Uladzislau Rezki - Some pagecache folioifications and simplifications from Matthew Wilcox - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series should have been in the non-MM tree, my bad - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages - Peter Xu utilized the PTE marker code for handling swapin errors - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand - zram support for multiple compression streams from Sergey Senozhatsky - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations - Vishal Moola removed the try_to_release_page() wrapper - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache - David Hildenbrand did some cleanup and repair work on KSM COW breaking - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range() - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages() - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting - David Hildenbrand has fixed some of our MM selftests for 32-bit machines - Many singleton patches, as usual * tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits) mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio mm: mmu_gather: allow more than one batch of delayed rmaps mm: fix typo in struct pglist_data code comment kmsan: fix memcpy tests mm: add cond_resched() in swapin_walk_pmd_entry() mm: do not show fs mm pc for VM_LOCKONFAULT pages selftests/vm: ksm_functional_tests: fixes for 32bit selftests/vm: cow: fix compile warning on 32bit selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem mm,thp,rmap: fix races between updates of subpages_mapcount mm: memcg: fix swapcached stat accounting mm: add nodes= arg to memory.reclaim mm: disable top-tier fallback to reclaim on proactive reclaim selftests: cgroup: make sure reclaim target memcg is unprotected selftests: cgroup: refactor proactive reclaim code to reclaim_until() mm: memcg: fix stale protection of reclaim target memcg mm/mmap: properly unaccount memory on mas_preallocate() failure omfs: remove ->writepage jfs: remove ->writepage ... |
||
Mel Gorman
|
1c0908d8e4 |
rtmutex: Add acquire semantics for rtmutex lock acquisition slow path
Jan Kara reported the following bug triggering on 6.0.5-rt14 running dbench on XFS on arm64. kernel BUG at fs/inode.c:625! Internal error: Oops - BUG: 0 [#1] PREEMPT_RT SMP CPU: 11 PID: 6611 Comm: dbench Tainted: G E 6.0.0-rt14-rt+ #1 pc : clear_inode+0xa0/0xc0 lr : clear_inode+0x38/0xc0 Call trace: clear_inode+0xa0/0xc0 evict+0x160/0x180 iput+0x154/0x240 do_unlinkat+0x184/0x300 __arm64_sys_unlinkat+0x48/0xc0 el0_svc_common.constprop.4+0xe4/0x2c0 do_el0_svc+0xac/0x100 el0_svc+0x78/0x200 el0t_64_sync_handler+0x9c/0xc0 el0t_64_sync+0x19c/0x1a0 It also affects 6.1-rc7-rt5 and affects a preempt-rt fork of 5.14 so this is likely a bug that existed forever and only became visible when ARM support was added to preempt-rt. The same problem does not occur on x86-64 and he also reported that converting sb->s_inode_wblist_lock to raw_spinlock_t makes the problem disappear indicating that the RT spinlock variant is the problem. Which in turn means that RT mutexes on ARM64 and any other weakly ordered architecture are affected by this independent of RT. Will Deacon observed: "I'd be more inclined to be suspicious of the slowpath tbh, as we need to make sure that we have acquire semantics on all paths where the lock can be taken. Looking at the rtmutex code, this really isn't obvious to me -- for example, try_to_take_rt_mutex() appears to be able to return via the 'takeit' label without acquire semantics and it looks like we might be relying on the caller's subsequent _unlock_ of the wait_lock for ordering, but that will give us release semantics which aren't correct." Sebastian Andrzej Siewior prototyped a fix that does work based on that comment but it was a little bit overkill and added some fences that should not be necessary. The lock owner is updated with an IRQ-safe raw spinlock held, but the spin_unlock does not provide acquire semantics which are needed when acquiring a mutex. Adds the necessary acquire semantics for lock owner updates in the slow path acquisition and the waiter bit logic. It successfully completed 10 iterations of the dbench workload while the vanilla kernel fails on the first iteration. [ bigeasy@linutronix.de: Initial prototype fix ] Fixes: |
||
Alexander Potapenko
|
1e8e4a7cc2 |
lockdep: allow instrumenting lockdep.c with KMSAN
Lockdep and KMSAN used to play badly together, causing deadlocks when KMSAN instrumentation of lockdep.c called lockdep functions recursively. Looks like this is no more the case, and a kernel can run (yet slower) with both KMSAN and lockdep enabled. This patch should fix false positives on wq_head->lock->dep_map, which KMSAN used to consider uninitialized because of lockdep.c not being instrumented. Link: https://lore.kernel.org/lkml/Y3b9AAEKp2Vr3e6O@sol.localdomain/ Link: https://lkml.kernel.org/r/20221128094541.2645890-1-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: Eric Biggers <ebiggers@kernel.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Marco Elver <elver@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Jason A. Donenfeld
|
8032bf1233 |
treewide: use get_random_u32_below() instead of deprecated function
This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Reviewed-by: SeongJae Park <sj@kernel.org> # for damon Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
||
|
Jason A. Donenfeld
|
81895a65ec |
treewide: use prandom_u32_max() when possible, part 1
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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