Commit Graph

516 Commits

Author SHA1 Message Date
Jakub Kicinski
b54a0d4094 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
bpf-next 2022-11-02

We've added 70 non-merge commits during the last 14 day(s) which contain
a total of 96 files changed, 3203 insertions(+), 640 deletions(-).

The main changes are:

1) Make cgroup local storage available to non-cgroup attached BPF programs
   such as tc BPF ones, from Yonghong Song.

2) Avoid unnecessary deadlock detection and failures wrt BPF task storage
   helpers, from Martin KaFai Lau.

3) Add LLVM disassembler as default library for dumping JITed code
   in bpftool, from Quentin Monnet.

4) Various kprobe_multi_link fixes related to kernel modules,
   from Jiri Olsa.

5) Optimize x86-64 JIT with emitting BMI2-based shift instructions,
   from Jie Meng.

6) Improve BPF verifier's memory type compatibility for map key/value
   arguments, from Dave Marchevsky.

7) Only create mmap-able data section maps in libbpf when data is exposed
   via skeletons, from Andrii Nakryiko.

8) Add an autoattach option for bpftool to load all object assets,
   from Wang Yufen.

9) Various memory handling fixes for libbpf and BPF selftests,
   from Xu Kuohai.

10) Initial support for BPF selftest's vmtest.sh on arm64,
    from Manu Bretelle.

11) Improve libbpf's BTF handling to dedup identical structs,
    from Alan Maguire.

12) Add BPF CI and denylist documentation for BPF selftests,
    from Daniel Müller.

13) Check BPF cpumap max_entries before doing allocation work,
    from Florian Lehner.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (70 commits)
  samples/bpf: Fix typo in README
  bpf: Remove the obsolte u64_stats_fetch_*_irq() users.
  bpf: check max_entries before allocating memory
  bpf: Fix a typo in comment for DFS algorithm
  bpftool: Fix spelling mistake "disasembler" -> "disassembler"
  selftests/bpf: Fix bpftool synctypes checking failure
  selftests/bpf: Panic on hard/soft lockup
  docs/bpf: Add documentation for new cgroup local storage
  selftests/bpf: Add test cgrp_local_storage to DENYLIST.s390x
  selftests/bpf: Add selftests for new cgroup local storage
  selftests/bpf: Fix test test_libbpf_str/bpf_map_type_str
  bpftool: Support new cgroup local storage
  libbpf: Support new cgroup local storage
  bpf: Implement cgroup storage available to non-cgroup-attached bpf progs
  bpf: Refactor some inode/task/sk storage functions for reuse
  bpf: Make struct cgroup btf id global
  selftests/bpf: Tracing prog can still do lookup under busy lock
  selftests/bpf: Ensure no task storage failure for bpf_lsm.s prog due to deadlock detection
  bpf: Add new bpf_task_storage_delete proto with no deadlock detection
  bpf: bpf_task_storage_delete_recur does lookup first before the deadlock check
  ...
====================

Link: https://lore.kernel.org/r/20221102062120.5724-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-02 08:18:27 -07:00
Yonghong Song
c4bcfb38a9 bpf: Implement cgroup storage available to non-cgroup-attached bpf progs
Similar to sk/inode/task storage, implement similar cgroup local storage.

There already exists a local storage implementation for cgroup-attached
bpf programs.  See map type BPF_MAP_TYPE_CGROUP_STORAGE and helper
bpf_get_local_storage(). But there are use cases such that non-cgroup
attached bpf progs wants to access cgroup local storage data. For example,
tc egress prog has access to sk and cgroup. It is possible to use
sk local storage to emulate cgroup local storage by storing data in socket.
But this is a waste as it could be lots of sockets belonging to a particular
cgroup. Alternatively, a separate map can be created with cgroup id as the key.
But this will introduce additional overhead to manipulate the new map.
A cgroup local storage, similar to existing sk/inode/task storage,
should help for this use case.

The life-cycle of storage is managed with the life-cycle of the
cgroup struct.  i.e. the storage is destroyed along with the owning cgroup
with a call to bpf_cgrp_storage_free() when cgroup itself
is deleted.

The userspace map operations can be done by using a cgroup fd as a key
passed to the lookup, update and delete operations.

Typically, the following code is used to get the current cgroup:
    struct task_struct *task = bpf_get_current_task_btf();
    ... task->cgroups->dfl_cgrp ...
and in structure task_struct definition:
    struct task_struct {
        ....
        struct css_set __rcu            *cgroups;
        ....
    }
With sleepable program, accessing task->cgroups is not protected by rcu_read_lock.
So the current implementation only supports non-sleepable program and supporting
sleepable program will be the next step together with adding rcu_read_lock
protection for rcu tagged structures.

Since map name BPF_MAP_TYPE_CGROUP_STORAGE has been used for old cgroup local
storage support, the new map name BPF_MAP_TYPE_CGRP_STORAGE is used
for cgroup storage available to non-cgroup-attached bpf programs. The old
cgroup storage supports bpf_get_local_storage() helper to get the cgroup data.
The new cgroup storage helper bpf_cgrp_storage_get() can provide similar
functionality. While old cgroup storage pre-allocates storage memory, the new
mechanism can also pre-allocate with a user space bpf_map_update_elem() call
to avoid potential run-time memory allocation failure.
Therefore, the new cgroup storage can provide all functionality w.r.t.
the old one. So in uapi bpf.h, the old BPF_MAP_TYPE_CGROUP_STORAGE is alias to
BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED to indicate the old cgroup storage can
be deprecated since the new one can provide the same functionality.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221026042850.673791-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-25 23:19:19 -07:00
Linus Torvalds
bb1a114646 cgroup fixes for v6.1-rc1
* Fix a recent regression where a sleeping kernfs function is called with
   css_set_lock (spinlock) held.
 
 * Revert the commit to enable cgroup1 support for cgroup_get_from_fd/file().
   Multiple users assume that the lookup only works for cgroup2 and breaks
   when fed a cgroup1 file. Instead, introduce a separate set of functions to
   lookup both v1 and v2 and use them where the user explicitly wants to
   support both versions.
 
 * Compat update for tools/perf/util/bpf_skel/bperf_cgroup.bpf.c.
 
 * Add Josef Bacik as a blkcg maintainer.
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Merge tag 'cgroup-for-6.1-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:

 - Fix a recent regression where a sleeping kernfs function is called
   with css_set_lock (spinlock) held

 - Revert the commit to enable cgroup1 support for cgroup_get_from_fd/file()

   Multiple users assume that the lookup only works for cgroup2 and
   breaks when fed a cgroup1 file. Instead, introduce a separate set of
   functions to lookup both v1 and v2 and use them where the user
   explicitly wants to support both versions.

 - Compat update for tools/perf/util/bpf_skel/bperf_cgroup.bpf.c.

 - Add Josef Bacik as a blkcg maintainer.

* tag 'cgroup-for-6.1-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  blkcg: Update MAINTAINERS entry
  mm: cgroup: fix comments for get from fd/file helpers
  perf stat: Support old kernels for bperf cgroup counting
  bpf: cgroup_iter: support cgroup1 using cgroup fd
  cgroup: add cgroup_v1v2_get_from_[fd/file]()
  Revert "cgroup: enable cgroup_get_from_file() on cgroup1"
  cgroup: Reorganize css_set_lock and kernfs path processing
2022-10-17 18:52:43 -07:00
Linus Torvalds
bd9a3dba18 PSI updates for v6.1:
- Various performance optimizations, resulting in a 4%-9% speedup
    in the mmtests/config-scheduler-perfpipe micro-benchmark.
 
  - New interface to turn PSI on/off on a per cgroup level.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-psi-2022-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull PSI updates from Ingo Molnar:

 - Various performance optimizations, resulting in a 4%-9% speedup in
   the mmtests/config-scheduler-perfpipe micro-benchmark.

 - New interface to turn PSI on/off on a per cgroup level.

* tag 'sched-psi-2022-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/psi: Per-cgroup PSI accounting disable/re-enable interface
  sched/psi: Cache parent psi_group to speed up group iteration
  sched/psi: Consolidate cgroup_psi()
  sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure
  sched/psi: Remove NR_ONCPU task accounting
  sched/psi: Optimize task switch inside shared cgroups again
  sched/psi: Move private helpers to sched/stats.h
  sched/psi: Save percpu memory when !psi_cgroups_enabled
  sched/psi: Don't create cgroup PSI files when psi_disabled
  sched/psi: Fix periodic aggregation shut off
2022-10-14 13:03:00 -07:00
Yosry Ahmed
b675d4bdfe mm: cgroup: fix comments for get from fd/file helpers
Fix the documentation comments for cgroup_[v1v2_]get_from_[fd/file]().

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-10-11 22:04:38 -10:00
Yosry Ahmed
a6d1ce5951 cgroup: add cgroup_v1v2_get_from_[fd/file]()
Add cgroup_v1v2_get_from_fd() and cgroup_v1v2_get_from_file() that
support both cgroup1 and cgroup2.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-10-11 06:50:03 -10:00
Linus Torvalds
27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Tejun Heo
03db771615 Revert "cgroup: enable cgroup_get_from_file() on cgroup1"
This reverts commit f3a2aebdd6.

The commit enabled looking up v1 cgroups via cgroup_get_from_file().
However, there are multiple users, including CLONE_INTO_CGROUP, which have
been assuming that it would only look up v2 cgroups. Returning v1 cgroups
breaks them.

Let's revert the commit and retry later with a separate lookup interface
which allows both v1 and v2.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/000000000000385cbf05ea3f1862@google.com
Cc: Yosry Ahmed <yosryahmed@google.com>
2022-10-10 11:08:17 -10:00
Michal Koutný
46307fd6e2 cgroup: Reorganize css_set_lock and kernfs path processing
The commit 74e4b956eb incorrectly wrapped kernfs_walk_and_get
(might_sleep) under css_set_lock (spinlock). css_set_lock is needed by
__cset_cgroup_from_root to ensure stable cset->cgrp_links but not for
kernfs_walk_and_get.

We only need to make sure that the returned root_cgrp won't be freed
under us. This is given in the case of global root because it is static
(cgrp_dfl_root.cgrp). When the root_cgrp is lower in the hierarchy, it
is pinned by cgroup_ns->root_cset (and `current` task cannot switch
namespace asynchronously so ns_proxy pins cgroup_ns).

Note this reasoning won't hold for root cgroups in v1 hierarchies,
therefore create a special-cased helper function just for the default
hierarchy.

Fixes: 74e4b956eb ("cgroup: Honor caller's cgroup NS when resolving path")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-10-10 10:23:18 -10:00
Linus Torvalds
adf4bfc4a9 cgroup changes for v6.1-rc1.
* cpuset now support isolated cpus.partition type, which will enable dynamic
   CPU isolation.
 * pids.peak added to remember the max number of pids used.
 * Holes in cgroup namespace plugged.
 * Internal cleanups.
 
 Note that for-6.1-fixes was pulled into for-6.1 twice. Both were for
 follow-up cleanups and each merge commit has details.
 
 Also, 8a693f7766 ("cgroup: Remove CFTYPE_PRESSURE") removes the flag used
 by PSI changes in the tip tree and the merged result won't compile due to
 the missing flag. Simply removing the struct init lines specifying the flag
 is the correct resolution. linux-next already contains the correct fix:
 
  https://lkml.kernel.org/r/20220912161812.072aaa3b@canb.auug.org.au
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Merge tag 'cgroup-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - cpuset now support isolated cpus.partition type, which will enable
   dynamic CPU isolation

 - pids.peak added to remember the max number of pids used

 - holes in cgroup namespace plugged

 - internal cleanups

* tag 'cgroup-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (25 commits)
  cgroup: use strscpy() is more robust and safer
  iocost_monitor: reorder BlkgIterator
  cgroup: simplify code in cgroup_apply_control
  cgroup: Make cgroup_get_from_id() prettier
  cgroup/cpuset: remove unreachable code
  cgroup: Remove CFTYPE_PRESSURE
  cgroup: Improve cftype add/rm error handling
  kselftest/cgroup: Add cpuset v2 partition root state test
  cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst
  cgroup/cpuset: Make partition invalid if cpumask change violates exclusivity rule
  cgroup/cpuset: Relocate a code block in validate_change()
  cgroup/cpuset: Show invalid partition reason string
  cgroup/cpuset: Add a new isolated cpus.partition type
  cgroup/cpuset: Relax constraints to partition & cpus changes
  cgroup/cpuset: Allow no-task partition to have empty cpuset.cpus.effective
  cgroup/cpuset: Miscellaneous cleanups & add helper functions
  cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset
  cgroup: add pids.peak interface for pids controller
  cgroup: Remove data-race around cgrp_dfl_visible
  cgroup: Fix build failure when CONFIG_SHRINKER_DEBUG
  ...
2022-10-10 11:12:25 -07:00
Linus Torvalds
30c999937f Scheduler changes for v6.1:
- Debuggability:
 
      - Change most occurances of BUG_ON() to WARN_ON_ONCE()
 
      - Reorganize & fix TASK_ state comparisons, turn it into a bitmap
 
      - Update/fix misc scheduler debugging facilities
 
  - Load-balancing & regular scheduling:
 
      - Improve the behavior of the scheduler in presence of lot of
        SCHED_IDLE tasks - in particular they should not impact other
        scheduling classes.
 
      - Optimize task load tracking, cleanups & fixes
 
      - Clean up & simplify misc load-balancing code
 
  - Freezer:
 
      - Rewrite the core freezer to behave better wrt thawing and be simpler
        in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
        all the fallout.
 
  - Deadline scheduler:
 
      - Fix the DL capacity-aware code
 
      - Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
 
      - Relax/optimize locking in task_non_contending()
 
  - Cleanups:
 
      - Factor out the update_current_exec_runtime() helper
 
      - Various cleanups, simplifications
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Debuggability:

   - Change most occurances of BUG_ON() to WARN_ON_ONCE()

   - Reorganize & fix TASK_ state comparisons, turn it into a bitmap

   - Update/fix misc scheduler debugging facilities

  Load-balancing & regular scheduling:

   - Improve the behavior of the scheduler in presence of lot of
     SCHED_IDLE tasks - in particular they should not impact other
     scheduling classes.

   - Optimize task load tracking, cleanups & fixes

   - Clean up & simplify misc load-balancing code

  Freezer:

   - Rewrite the core freezer to behave better wrt thawing and be
     simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
     fixing/adjusting all the fallout.

  Deadline scheduler:

   - Fix the DL capacity-aware code

   - Factor out dl_task_is_earliest_deadline() &
     replenish_dl_new_period()

   - Relax/optimize locking in task_non_contending()

  Cleanups:

   - Factor out the update_current_exec_runtime() helper

   - Various cleanups, simplifications"

* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  sched: Fix more TASK_state comparisons
  sched: Fix TASK_state comparisons
  sched/fair: Move call to list_last_entry() in detach_tasks
  sched/fair: Cleanup loop_max and loop_break
  sched/fair: Make sure to try to detach at least one movable task
  sched: Show PF_flag holes
  freezer,sched: Rewrite core freezer logic
  sched: Widen TAKS_state literals
  sched/wait: Add wait_event_state()
  sched/completion: Add wait_for_completion_state()
  sched: Add TASK_ANY for wait_task_inactive()
  sched: Change wait_task_inactive()s match_state
  freezer,umh: Clean up freezer/initrd interaction
  freezer: Have {,un}lock_system_sleep() save/restore flags
  sched: Rename task_running() to task_on_cpu()
  sched/fair: Cleanup for SIS_PROP
  sched/fair: Default to false in test_idle_cores()
  sched/fair: Remove useless check in select_idle_core()
  sched/fair: Avoid double search on same cpu
  sched/fair: Remove redundant check in select_idle_smt()
  ...
2022-10-10 09:10:28 -07:00
Linus Torvalds
e8bc52cb8d Driver core changes for 6.1-rc1
Here is the big set of driver core and debug printk changes for 6.1-rc1.
 Included in here is:
 	- dynamic debug updates for the core and the drm subsystem.  The
 	  drm changes have all been acked by the relevant maintainers.
 	- kernfs fixes for syzbot reported problems
 	- kernfs refactors and updates for cgroup requirements
 	- magic number cleanups and removals from the kernel tree (they
 	  were not being used and they really did not actually do
 	  anything.)
 	- other tiny cleanups
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the big set of driver core and debug printk changes for
  6.1-rc1. Included in here is:

   - dynamic debug updates for the core and the drm subsystem. The drm
     changes have all been acked by the relevant maintainers

   - kernfs fixes for syzbot reported problems

   - kernfs refactors and updates for cgroup requirements

   - magic number cleanups and removals from the kernel tree (they were
     not being used and they really did not actually do anything)

   - other tiny cleanups

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (74 commits)
  docs: filesystems: sysfs: Make text and code for ->show() consistent
  Documentation: NBD_REQUEST_MAGIC isn't a magic number
  a.out: restore CMAGIC
  device property: Add const qualifier to device_get_match_data() parameter
  drm_print: add _ddebug descriptor to drm_*dbg prototypes
  drm_print: prefer bare printk KERN_DEBUG on generic fn
  drm_print: optimize drm_debug_enabled for jump-label
  drm-print: add drm_dbg_driver to improve namespace symmetry
  drm-print.h: include dyndbg header
  drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro
  drm_print: interpose drm_*dbg with forwarding macros
  drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers.
  drm_print: condense enum drm_debug_category
  debugfs: use DEFINE_SHOW_ATTRIBUTE to define debugfs_regset32_fops
  driver core: use IS_ERR_OR_NULL() helper in device_create_groups_vargs()
  Documentation: ENI155_MAGIC isn't a magic number
  Documentation: NBD_REPLY_MAGIC isn't a magic number
  nbd: remove define-only NBD_MAGIC, previously magic number
  Documentation: FW_HEADER_MAGIC isn't a magic number
  Documentation: EEPROM_MAGIC_VALUE isn't a magic number
  ...
2022-10-07 17:04:10 -07:00
Jakub Kicinski
accc3b4a57 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29 14:30:51 -07:00
Yu Zhao
354ed59744 mm: multi-gen LRU: kill switch
Add /sys/kernel/mm/lru_gen/enabled as a kill switch. Components that
can be disabled include:
  0x0001: the multi-gen LRU core
  0x0002: walking page table, when arch_has_hw_pte_young() returns
          true
  0x0004: clearing the accessed bit in non-leaf PMD entries, when
          CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG=y
  [yYnN]: apply to all the components above
E.g.,
  echo y >/sys/kernel/mm/lru_gen/enabled
  cat /sys/kernel/mm/lru_gen/enabled
  0x0007
  echo 5 >/sys/kernel/mm/lru_gen/enabled
  cat /sys/kernel/mm/lru_gen/enabled
  0x0005

NB: the page table walks happen on the scale of seconds under heavy memory
pressure, in which case the mmap_lock contention is a lesser concern,
compared with the LRU lock contention and the I/O congestion.  So far the
only well-known case of the mmap_lock contention happens on Android, due
to Scudo [1] which allocates several thousand VMAs for merely a few
hundred MBs.  The SPF and the Maple Tree also have provided their own
assessments [2][3].  However, if walking page tables does worsen the
mmap_lock contention, the kill switch can be used to disable it.  In this
case the multi-gen LRU will suffer a minor performance degradation, as
shown previously.

Clearing the accessed bit in non-leaf PMD entries can also be disabled,
since this behavior was not tested on x86 varieties other than Intel and
AMD.

[1] https://source.android.com/devices/tech/debug/scudo
[2] https://lore.kernel.org/r/20220128131006.67712-1-michel@lespinasse.org/
[3] https://lore.kernel.org/r/20220426150616.3937571-1-Liam.Howlett@oracle.com/

Link: https://lkml.kernel.org/r/20220918080010.2920238-11-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Brian Geffon <bgeffon@google.com>
Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Acked-by: Steven Barrett <steven@liquorix.net>
Acked-by: Suleiman Souhlal <suleiman@google.com>
Tested-by: Daniel Byrne <djbyrne@mtu.edu>
Tested-by: Donald Carr <d@chaos-reins.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>
Tested-by: Shuang Zhai <szhai2@cs.rochester.edu>
Tested-by: Sofia Trinh <sofia.trinh@edi.works>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Larabel <Michael@MichaelLarabel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:10 -07:00
ye xingchen
8619e94d3b cgroup: use strscpy() is more robust and safer
The implementation of strscpy() is more robust and safer.

That's now the recommended way to copy NUL terminated strings.

Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-23 17:27:02 -10:00
William Dean
61c41711b1 cgroup: simplify code in cgroup_apply_control
It could directly return 'cgroup_update_dfl_csses' to simplify code.

Signed-off-by: William Dean <williamsukatube@163.com>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-23 16:52:00 -10:00
Tejun Heo
7e1eb5437d cgroup: Make cgroup_get_from_id() prettier
After merging 836ac87d ("cgroup: fix cgroup_get_from_id") into for-6.1, its
combination with two commits in for-6.1 - 4534dee9 ("cgroup: cgroup: Honor
caller's cgroup NS when resolving cgroup id") and fa7e439c ("cgroup:
Homogenize cgroup_get_from_id() return value") - makes the gotos in the
error handling path too ugly while not adding anything of value.

All that the gotos are saving is one extra kernfs_put() call. Let's remove
the gotos and perform error returns directly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Michal Koutný <mkoutny@suse.com>
2022-09-23 07:23:06 -10:00
Tejun Heo
026e14a276 Merge branch 'for-6.0-fixes' into for-6.1
for-6.0 has the following fix for cgroup_get_from_id().

  836ac87d ("cgroup: fix cgroup_get_from_id")

which conflicts with the following two commits in for-6.1.

  4534dee9 ("cgroup: cgroup: Honor caller's cgroup NS when resolving cgroup id")
  fa7e439c ("cgroup: Homogenize cgroup_get_from_id() return value")

While the resolution is straightforward, the code ends up pretty ugly
afterwards. Let's pull for-6.0-fixes into for-6.1 so that the code can be
fixed up there.

Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-23 07:19:38 -10:00
Ming Lei
df02452f3d cgroup: cgroup_get_from_id() must check the looked-up kn is a directory
cgroup has to be one kernfs dir, otherwise kernel panic is caused,
especially cgroup id is provide from userspace.

Reported-by: Marco Patalano <mpatalan@redhat.com>
Fixes: 6b658c4863 ("scsi: cgroup: Add cgroup_get_from_id()")
Cc: Muneendra <muneendra.kumar@broadcom.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-23 07:18:45 -10:00
Greg Kroah-Hartman
a791dc1353 Linux 6.0-rc5
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Merge 6.0-rc5 into driver-core-next

We need the driver core and debugfs changes in this branch.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-12 16:51:22 +02:00
Chengming Zhou
34f26a1561 sched/psi: Per-cgroup PSI accounting disable/re-enable interface
PSI accounts stalls for each cgroup separately and aggregates it
at each level of the hierarchy. This may cause non-negligible overhead
for some workloads when under deep level of the hierarchy.

commit 3958e2d0c3 ("cgroup: make per-cgroup pressure stall tracking configurable")
make PSI to skip per-cgroup stall accounting, only account system-wide
to avoid this each level overhead.

But for our use case, we also want leaf cgroup PSI stats accounted for
userspace adjustment on that cgroup, apart from only system-wide adjustment.

So this patch introduce a per-cgroup PSI accounting disable/re-enable
interface "cgroup.pressure", which is a read-write single value file that
allowed values are "0" and "1", the defaults is "1" so per-cgroup
PSI stats is enabled by default.

Implementation details:

It should be relatively straight-forward to disable and re-enable
state aggregation, time tracking, averaging on a per-cgroup level,
if we can live with losing history from while it was disabled.
I.e. the avgs will restart from 0, total= will have gaps.

But it's hard or complex to stop/restart groupc->tasks[] updates,
which is not implemented in this patch. So we always update
groupc->tasks[] and PSI_ONCPU bit in psi_group_change() even when
the cgroup PSI stats is disabled.

Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/20220907090332.2078-1-zhouchengming@bytedance.com
2022-09-09 11:08:33 +02:00
Chengming Zhou
57899a6610 sched/psi: Consolidate cgroup_psi()
cgroup_psi() can't return psi_group for root cgroup, so we have many
open code "psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi".

This patch move cgroup_psi() definition to <linux/psi.h>, in which
we can return psi_system for root cgroup, so can handle all cgroups.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/r/20220825164111.29534-9-zhouchengming@bytedance.com
2022-09-09 11:08:33 +02:00
Chengming Zhou
52b1364ba0 sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure
Now PSI already tracked workload pressure stall information for
CPU, memory and IO. Apart from these, IRQ/SOFTIRQ could have
obvious impact on some workload productivity, such as web service
workload.

When CONFIG_IRQ_TIME_ACCOUNTING, we can get IRQ/SOFTIRQ delta time
from update_rq_clock_task(), in which we can record that delta
to CPU curr task's cgroups as PSI_IRQ_FULL status.

Note we don't use PSI_IRQ_SOME since IRQ/SOFTIRQ always happen in
the current task on the CPU, make nothing productive could run
even if it were runnable, so we only use PSI_IRQ_FULL.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/r/20220825164111.29534-8-zhouchengming@bytedance.com
2022-09-09 11:08:32 +02:00
Chengming Zhou
58d8c2586c sched/psi: Don't create cgroup PSI files when psi_disabled
commit 3958e2d0c3 ("cgroup: make per-cgroup pressure stall tracking configurable")
make PSI can be configured to skip per-cgroup stall accounting. And
doesn't expose PSI files in cgroup hierarchy.

This patch do the same thing when psi_disabled.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/r/20220825164111.29534-3-zhouchengming@bytedance.com
2022-09-09 11:08:31 +02:00
Peter Zijlstra
0fb7b6f9d3 Merge branch 'driver-core/driver-core-next'
Pull in dependent cgroup patches

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-09-09 11:08:30 +02:00
Peter Zijlstra
f5d39b0208 freezer,sched: Rewrite core freezer logic
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

	freezer_do_not_count();
	schedule();
	freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

	TASK_FREEZABLE	-> TASK_FROZEN
	__TASK_STOPPED	-> TASK_FROZEN
	__TASK_TRACED	-> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
2022-09-07 21:53:50 +02:00
Jiapeng Chong
c478bd8836 cgroup/cpuset: remove unreachable code
The function sched_partition_show cannot execute seq_puts, delete the
invalid code.

kernel/cgroup/cpuset.c:2849 sched_partition_show() warn: ignoring unreachable code.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2087
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-07 05:30:29 -10:00
Paolo Abeni
2786bcff28 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-09-05

The following pull-request contains BPF updates for your *net-next* tree.

We've added 106 non-merge commits during the last 18 day(s) which contain
a total of 159 files changed, 5225 insertions(+), 1358 deletions(-).

There are two small merge conflicts, resolve them as follows:

1) tools/testing/selftests/bpf/DENYLIST.s390x

  Commit 27e23836ce ("selftests/bpf: Add lru_bug to s390x deny list") in
  bpf tree was needed to get BPF CI green on s390x, but it conflicted with
  newly added tests on bpf-next. Resolve by adding both hunks, result:

  [...]
  lru_bug                                  # prog 'printk': failed to auto-attach: -524
  setget_sockopt                           # attach unexpected error: -524                                               (trampoline)
  cb_refs                                  # expected error message unexpected error: -524                               (trampoline)
  cgroup_hierarchical_stats                # JIT does not support calling kernel function                                (kfunc)
  htab_update                              # failed to attach: ERROR: strerror_r(-524)=22                                (trampoline)
  [...]

2) net/core/filter.c

  Commit 1227c1771d ("net: Fix data-races around sysctl_[rw]mem_(max|default).")
  from net tree conflicts with commit 29003875bd ("bpf: Change bpf_setsockopt(SOL_SOCKET)
  to reuse sk_setsockopt()") from bpf-next tree. Take the code as it is from
  bpf-next tree, result:

  [...]
	if (getopt) {
		if (optname == SO_BINDTODEVICE)
			return -EINVAL;
		return sk_getsockopt(sk, SOL_SOCKET, optname,
				     KERNEL_SOCKPTR(optval),
				     KERNEL_SOCKPTR(optlen));
	}

	return sk_setsockopt(sk, SOL_SOCKET, optname,
			     KERNEL_SOCKPTR(optval), *optlen);
  [...]

The main changes are:

1) Add any-context BPF specific memory allocator which is useful in particular for BPF
   tracing with bonus of performance equal to full prealloc, from Alexei Starovoitov.

2) Big batch to remove duplicated code from bpf_{get,set}sockopt() helpers as an effort
   to reuse the existing core socket code as much as possible, from Martin KaFai Lau.

3) Extend BPF flow dissector for BPF programs to just augment the in-kernel dissector
   with custom logic. In other words, allow for partial replacement, from Shmulik Ladkani.

4) Add a new cgroup iterator to BPF with different traversal options, from Hao Luo.

5) Support for BPF to collect hierarchical cgroup statistics efficiently through BPF
   integration with the rstat framework, from Yosry Ahmed.

6) Support bpf_{g,s}et_retval() under more BPF cgroup hooks, from Stanislav Fomichev.

7) BPF hash table and local storages fixes under fully preemptible kernel, from Hou Tao.

8) Add various improvements to BPF selftests and libbpf for compilation with gcc BPF
   backend, from James Hilliard.

9) Fix verifier helper permissions and reference state management for synchronous
   callbacks, from Kumar Kartikeya Dwivedi.

10) Add support for BPF selftest's xskxceiver to also be used against real devices that
    support MAC loopback, from Maciej Fijalkowski.

11) Various fixes to the bpf-helpers(7) man page generation script, from Quentin Monnet.

12) Document BPF verifier's tnum_in(tnum_range(), ...) gotchas, from Shung-Hsi Yu.

13) Various minor misc improvements all over the place.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (106 commits)
  bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc.
  bpf: Remove usage of kmem_cache from bpf_mem_cache.
  bpf: Remove prealloc-only restriction for sleepable bpf programs.
  bpf: Prepare bpf_mem_alloc to be used by sleepable bpf programs.
  bpf: Remove tracing program restriction on map types
  bpf: Convert percpu hash map to per-cpu bpf_mem_alloc.
  bpf: Add percpu allocation support to bpf_mem_alloc.
  bpf: Batch call_rcu callbacks instead of SLAB_TYPESAFE_BY_RCU.
  bpf: Adjust low/high watermarks in bpf_mem_cache
  bpf: Optimize call_rcu in non-preallocated hash map.
  bpf: Optimize element count in non-preallocated hash map.
  bpf: Relax the requirement to use preallocated hash maps in tracing progs.
  samples/bpf: Reduce syscall overhead in map_perf_test.
  selftests/bpf: Improve test coverage of test_maps
  bpf: Convert hash map to bpf_mem_alloc.
  bpf: Introduce any context BPF specific memory allocator.
  selftest/bpf: Add test for bpf_getsockopt()
  bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt()
  bpf: Change bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt()
  bpf: Change bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt()
  ...
====================

Link: https://lore.kernel.org/r/20220905161136.9150-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-06 23:21:18 +02:00
Tejun Heo
8a693f7766 cgroup: Remove CFTYPE_PRESSURE
CFTYPE_PRESSURE is used to flag PSI related files so that they are not
created if PSI is disabled during boot. It's a bit weird to use a generic
flag to mark a specific file type. Let's instead move the PSI files into its
own cftypes array and add/rm them conditionally. This is a bit more code but
cleaner.

No userland visible changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
2022-09-06 09:38:55 -10:00
Tejun Heo
0083d27b21 cgroup: Improve cftype add/rm error handling
Let's track whether a cftype is currently added or not using a new flag
__CFTYPE_ADDED so that duplicate operations can be failed safely and
consistently allow using empty cftypes.

Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-06 09:38:42 -10:00
Waiman Long
d7c8142d5a cgroup/cpuset: Make partition invalid if cpumask change violates exclusivity rule
Currently, changes in "cpust.cpus" of a partition root is not allowed if
it violates the sibling cpu exclusivity rule when the check is done
in the validate_change() function. That is inconsistent with the
other cpuset changes that are always allowed but may make a partition
invalid.

Update the cpuset code to allow cpumask change even if it violates the
sibling cpu exclusivity rule, but invalidate the partition instead
just like the other changes. However, other sibling partitions with
conflicting cpumask will also be invalidated in order to not violating
the exclusivity rule. This behavior is specific to this partition
rule violation.

Note that a previous commit has made sibling cpu exclusivity rule check
the last check of validate_change(). So if -EINVAL is returned, we can
be sure that sibling cpu exclusivity rule violation is the only rule
that is broken.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 10:47:28 -10:00
Waiman Long
74027a6535 cgroup/cpuset: Relocate a code block in validate_change()
This patch moves down the exclusive cpu and memory check in
validate_change(). There is no functional change.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 10:47:28 -10:00
Waiman Long
7476a636d3 cgroup/cpuset: Show invalid partition reason string
There are a number of different reasons which can cause a partition to
become invalid. A user seeing an invalid partition may not know exactly
why. To help user to get a better understanding of the underlying reason,
The cpuset.cpus.partition control file, when read, will now report the
reason why a partition become invalid. When a partition does become
invalid, reading the control file will show "root invalid (<reason>)"
where <reason> is a string that describes why the partition is invalid.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 10:47:27 -10:00
Waiman Long
f28e22441f cgroup/cpuset: Add a new isolated cpus.partition type
Cpuset v1 uses the sched_load_balance control file to determine if load
balancing should be enabled.  Cpuset v2 gets rid of sched_load_balance
as its use may require disabling load balancing at cgroup root.

For workloads that require very low latency like DPDK, the latency
jitters caused by periodic load balancing may exceed the desired
latency limit.

When cpuset v2 is in use, the only way to avoid this latency cost is to
use the "isolcpus=" kernel boot option to isolate a set of CPUs. After
the kernel boot, however, there is no way to add or remove CPUs from
this isolated set. For workloads that are more dynamic in nature, that
means users have to provision enough CPUs for the worst case situation
resulting in excess idle CPUs.

To address this issue for cpuset v2, a new cpuset.cpus.partition type
"isolated" is added which allows the creation of a cpuset partition
without load balancing. This will allow system administrators to
dynamically adjust the size of isolated partition to the current need
of the workload without rebooting the system.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 10:47:27 -10:00
Waiman Long
f0af1bfc27 cgroup/cpuset: Relax constraints to partition & cpus changes
Currently, enabling a partition root is only allowed if all the
constraints of a valid partition are satisfied. Even changes to
"cpuset.cpus" may not be allowed in some cases. Moreover, there are
limits to changes made to a parent cpuset if it is a valid partition
root. This is contrary to the general cgroup v2 philosophy.

This patch relaxes the constraints of changing the state of "cpuset.cpus"
and "cpuset.cpus.partition". Now all valid changes ("member" or "root")
to "cpuset.cpus.partition" are allowed even if there are child cpusets
underneath it.

Trying to make a cpuset a partition root, however, will cause its state
to become invalid if the following constraints of a valid partition
root are not satisfied.

 1) The "cpuset.cpus" is non-empty and exclusive.
 2) The parent cpuset is a valid partition root.
 3) The "cpuset.cpus" overlaps parent's "cpuset.cpus".

Similarly, almost all changes to "cpuset.cpus" are allowed with the
exception that if the underlying CS_CPU_EXCLUSIVE flag is set, the
exclusivity rule will still apply.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 10:47:27 -10:00
Waiman Long
e2d59900d9 cgroup/cpuset: Allow no-task partition to have empty cpuset.cpus.effective
Currently, a partition root cannot have empty "cpuset.cpus.effective".
As a result, a parent partition root cannot distribute out all its
CPUs to child partitions with no CPUs left. However in most cases,
there shouldn't be any tasks associated with intermediate nodes of the
default hierarchy. So the current rule is too restrictive and can waste
valuable CPU resource.

To address this issue, we are now allowing a partition to have empty
"cpuset.cpus.effective" as long as it has no task. Since cpuset is
threaded, no-internal-process rule does not apply. So it is possible
to have tasks in a partition root with child sub-partitions even though
that should be uncommon.

A parent partition with no task can now have all its CPUs distributed out
to its child partitions. The top cpuset always have some house-keeping
tasks running and so its list of effective cpu can't be empty.

Once a partition with empty "cpuset.cpus.effective" is formed, no
new task can be moved into it until "cpuset.cpus.effective" becomes
non-empty.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 10:47:27 -10:00
Waiman Long
18065ebe9b cgroup/cpuset: Miscellaneous cleanups & add helper functions
The partition root state (PRS) macro names do not currently match the
external names. Change them to match the external names and add helper
functions to read or change the state.

Shorten the cpuset argument of update_parent_subparts_cpumask() to cs
to match other cpuset functions.

Remove the new_prs argument from notify_partition_change() as the
cs->partition_root_state has already been set to new_prs before it
is called.

There is no functional change.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 10:47:27 -10:00
Waiman Long
ec5fbdfb99 cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset
Previously, update_tasks_cpumask() is not supposed to be called with
top cpuset. With cpuset partition that takes CPUs away from the top
cpuset, adjusting the cpus_mask of the tasks in the top cpuset is
necessary. Percpu kthreads, however, are ignored.

Fixes: ee8dde0cd2 ("cpuset: Add new v2 cpuset.sched.partition flag")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 10:47:27 -10:00
Josh Don
5251c6c436 cgroup: add pids.peak interface for pids controller
pids.peak tracks the high watermark of usage for number of pids. This
helps give a better baseline on which to set pids.max. Polling
pids.current isn't really feasible, since it would potentially miss
short-lived spikes.

This interface is analogous to memory.peak.

Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-09-04 09:26:51 -10:00
Tejun Heo
dc79ec1b23 cgroup: Remove data-race around cgrp_dfl_visible
There's a seemingly harmless data-race around cgrp_dfl_visible detected by
kernel concurrency sanitizer. Let's remove it by throwing WRITE/READ_ONCE at
it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Abhishek Shah <abhishek.shah@columbia.edu>
Cc: Gabriel Ryan <gabe@cs.columbia.edu>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Link: https://lore.kernel.org/netdev/20220819072256.fn7ctciefy4fc4cu@wittgenstein/
2022-09-04 09:16:19 -10:00
Tejun Heo
e2691f6b44 cgroup: Implement cgroup_file_show()
Add cgroup_file_show() which allows toggling visibility of a cgroup file
using the new kernfs_show(). This will be used to hide psi interface files
on cgroups where it's disabled.

Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220828050440.734579-10-tj@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-01 18:08:44 +02:00
Tetsuo Handa
075b593f54 cgroup: Use cgroup_attach_{lock,unlock}() from cgroup_attach_task_all()
No behavior changes; preparing for potential locking changes in future.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by:Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-26 11:14:34 -10:00
Tejun Heo
265efc941f Merge branch 'for-6.0-fixes' into for-6.1
Pulling to receive 43626dade3 ("group: Add missing cpus_read_lock() to
cgroup_attach_task_all()") for a follow-up patch.
2022-08-26 11:13:39 -10:00
Michal Koutný
fa7e439cf9 cgroup: Homogenize cgroup_get_from_id() return value
Cgroup id is user provided datum hence extend its return domain to
include possible error reason (similar to cgroup_get_from_fd()).

This change also fixes commit d4ccaf58a8 ("bpf: Introduce cgroup
iter") that would use NULL instead of proper error handling in
d4ccaf58a8 ("bpf: Introduce cgroup iter").

Additionally, neither of: fc_appid_store, bpf_iter_attach_cgroup,
mem_cgroup_get_from_ino (callers of cgroup_get_from_fd) is built without
CONFIG_CGROUPS (depends via CONFIG_BLK_CGROUP, direct, transitive
CONFIG_MEMCG respectively) transitive, so drop the singular definition
not needed with !CONFIG_CGROUPS.

Fixes: d4ccaf58a8 ("bpf: Introduce cgroup iter")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-26 10:57:41 -10:00
Michal Koutný
4534dee941 cgroup: cgroup: Honor caller's cgroup NS when resolving cgroup id
Cgroup ids are resolved in the global scope. That may be needed sometime
(in future) but currently it violates virtual view provided through
cgroup namespaces.

There are currently following users of the resolution:
- fc_appid_store
- bpf_iter_attach_cgroup
- mem_cgroup_get_from_ino

None of the is a called on behalf of kernel but the resolution is made
with proper userspace context, hence the default to current->nsproxy
makes sens. (This doesn't rule out cgroup_get_from_id with cgroup NS
parameter in the future.)

Since cgroup ids are defined on v2 hierarchy only, we simply check
existence in the cgroup namespace by looking at ancestry on the default
hierarchy.

Fixes: 6b658c4863 ("scsi: cgroup: Add cgroup_get_from_id()")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-26 10:57:10 -10:00
Michal Koutný
74e4b956eb cgroup: Honor caller's cgroup NS when resolving path
cgroup_get_from_path() is not widely used function. Its callers presume
the path is resolved under cgroup namespace. (There is one caller
currently and resolving in init NS won't make harm (netfilter). However,
future users may be subject to different effects when resolving
globally.)
Since, there's currently no use for the global resolution, modify the
existing function to take cgroup NS into account.

Fixes: a79a908fd2 ("cgroup: introduce cgroup namespaces")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-26 10:56:26 -10:00
Jakub Kicinski
880b0dd94f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/mellanox/mlx5/core/en_fs.c
  21234e3a84 ("net/mlx5e: Fix use after free in mlx5e_fs_init()")
  c7eafc5ed0 ("net/mlx5e: Convert ethtool_steering member of flow_steering struct to pointer")
https://lore.kernel.org/all/20220825104410.67d4709c@canb.auug.org.au/
https://lore.kernel.org/all/20220823055533.334471-1-saeed@kernel.org/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-25 16:07:42 -07:00
Yosry Ahmed
a319185be9 cgroup: bpf: enable bpf programs to integrate with rstat
Enable bpf programs to make use of rstat to collect cgroup hierarchical
stats efficiently:
- Add cgroup_rstat_updated() kfunc, for bpf progs that collect stats.
- Add cgroup_rstat_flush() sleepable kfunc, for bpf progs that read stats.
- Add an empty bpf_rstat_flush() hook that is called during rstat
  flushing, for bpf progs that flush stats to attach to. Attaching a bpf
  prog to this hook effectively registers it as a flush callback.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220824233117.1312810-4-haoluo@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-25 11:35:37 -07:00
Tetsuo Handa
43626dade3 cgroup: Add missing cpus_read_lock() to cgroup_attach_task_all()
syzbot is hitting percpu_rwsem_assert_held(&cpu_hotplug_lock) warning at
cpuset_attach() [1], for commit 4f7e723643 ("cgroup: Fix
threadgroup_rwsem <-> cpus_read_lock() deadlock") missed that
cpuset_attach() is also called from cgroup_attach_task_all().
Add cpus_read_lock() like what cgroup_procs_write_start() does.

Link: https://syzkaller.appspot.com/bug?extid=29d3a3b4d86c8136ad9e [1]
Reported-by: syzbot <syzbot+29d3a3b4d86c8136ad9e@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 4f7e723643 ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock")
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-25 07:36:30 -10:00
Jing-Ting Wu
763f4fb76e cgroup: Fix race condition at rebind_subsystems()
Root cause:
The rebind_subsystems() is no lock held when move css object from A
list to B list,then let B's head be treated as css node at
list_for_each_entry_rcu().

Solution:
Add grace period before invalidating the removed rstat_css_node.

Reported-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Suggested-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Tested-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Link: https://lore.kernel.org/linux-arm-kernel/d8f0bc5e2fb6ed259f9334c83279b4c011283c41.camel@mediatek.com/T/
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Fixes: a7df69b81a ("cgroup: rstat: support cgroup1")
Cc: stable@vger.kernel.org # v5.13+
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-23 08:11:06 -10:00