16427 Commits

Author SHA1 Message Date
Oleg Nesterov
46ef2be0d1 tracing: Change tracing_buffers_fops to rely on tracing_get_cpu()
tracing_buffers_open() is racy, the memory inode->i_private points
to can be already freed.

Change debugfs_create_file("trace_pipe_raw", data) caller to pass
"data = tr", tracing_buffers_open() can use tracing_get_cpu().

Change debugfs_create_file("snapshot_raw_fops", data) caller too,
this file uses tracing_buffers_open/release.

Link: http://lkml.kernel.org/r/20130723152600.GA23720@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-24 11:22:51 -04:00
Oleg Nesterov
15544209cb tracing: Change tracing_pipe_fops() to rely on tracing_get_cpu()
tracing_open_pipe() is racy, the memory inode->i_private points to
can be already freed.

Change debugfs_create_file("trace_pipe", data) callers to to pass
"data = tr", tracing_open_pipe() can use tracing_get_cpu().

Link: http://lkml.kernel.org/r/20130723152557.GA23717@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-24 11:22:51 -04:00
Oleg Nesterov
649e9c70da tracing: Introduce trace_create_cpu_file() and tracing_get_cpu()
Every "file_operations" used by tracing_init_debugfs_percpu is buggy.
f_op->open/etc does:

	1. struct trace_cpu *tc = inode->i_private;
	   struct trace_array *tr = tc->tr;

	2. trace_array_get(tr) or fail;

	3. do_something(tc);

But tc (and tr) can be already freed before trace_array_get() is called.
And it doesn't matter whether this file is per-cpu or it was created by
init_tracer_debugfs(), free_percpu() or kfree() are equally bad.

Note that even 1. is not safe, the freed memory can be unmapped. But even
if it was safe trace_array_get() can wrongly succeed if we also race with
the next new_instance_create() which can re-allocate the same tr, or tc
was overwritten and ->tr points to the valid tr. In this case 3. uses the
freed/reused memory.

Add the new trivial helper, trace_create_cpu_file() which simply calls
trace_create_file() and encodes "cpu" in "struct inode". Another helper,
tracing_get_cpu() will be used to read cpu_nr-or-RING_BUFFER_ALL_CPUS.

The patch abuses ->i_cdev to encode the number, it is never used unless
the file is S_ISCHR(). But we could use something else, say, i_bytes or
even ->d_fsdata. In any case this hack is hidden inside these 2 helpers,
it would be trivial to change them if needed.

This patch only changes tracing_init_debugfs_percpu() to use the new
trace_create_cpu_file(), the next patches will change file_operations.

Note: tracing_get_cpu(inode) is always safe but you can't trust the
result unless trace_array_get() was called, without trace_types_lock
which acts as a barrier it can wrongly return RING_BUFFER_ALL_CPUS.

Link: http://lkml.kernel.org/r/20130723152554.GA23710@redhat.com

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-24 11:22:13 -04:00
Linus Torvalds
c2468d32f5 Merge branch 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup changes from Tejun Heo:
 "This contains two patches, both of which aren't fixes per-se but I
  think it'd be better to fast-track them.

  One removes bcache_subsys_id which was added without proper review
  through the block tree.  Fortunately, bcache cgroup code is
  unconditionally disabled, so this was never exposed to userland.  The
  cgroup subsys_id is removed.  Kent will remove the affected (disabled)
  code through bcache branch.

  The other simplifies task_group_path_from_hierarchy().  The function
  doesn't currently have in-kernel users but there are external code and
  development going on dependent on the function and making the function
  available for 3.11 would make things go smoother"

* 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: replace task_cgroup_path_from_hierarchy() with task_cgroup_path()
  cgroup: remove bcache_subsys_id which got added stealthily
2013-07-23 15:48:35 -07:00
David Howells
42577ca8c3 Fix __wait_on_atomic_t() to call the action func if the counter != 0
Fix __wait_on_atomic_t() so that it calls the action func if the counter != 0
rather than if the counter is 0 so as to be analogous to __wait_on_bit().

Thanks to Yacine who found this by visual inspection.

This will affect FS-Cache in that it will could fail to sleep correctly when
trying to clean up after a netfs cookie is withdrawn.

Reported-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
cc: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-23 15:46:48 -07:00
Peter Zijlstra
7d9ffa8961 sched: Micro-optimize the smart wake-affine logic
Smart wake-affine is using node-size as the factor currently, but the overhead
of the mask operation is high.

Thus, this patch introduce the 'sd_llc_size' percpu variable, which will record
the highest cache-share domain size, and make it to be the new factor, in order
to reduce the overhead and make it more reasonable.

Tested-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Tested-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/51D5008E.6030102@linux.vnet.ibm.com
[ Tidied up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23 12:22:06 +02:00
Michael Wang
62470419e9 sched: Implement smarter wake-affine logic
The wake-affine scheduler feature is currently always trying to pull
the wakee close to the waker. In theory this should be beneficial if
the waker's CPU caches hot data for the wakee, and it's also beneficial
in the extreme ping-pong high context switch rate case.

Testing shows it can benefit hackbench up to 15%.

However, the feature is somewhat blind, from which some workloads
such as pgbench suffer. It's also time-consuming algorithmically.

Testing shows it can damage pgbench up to 50% - far more than the
benefit it brings in the best case.

So wake-affine should be smarter and it should realize when to
stop its thankless effort at trying to find a suitable CPU to wake on.

This patch introduces 'wakee_flips', which will be increased each
time the task flips (switches) its wakee target.

So a high 'wakee_flips' value means the task has more than one
wakee, and the bigger the number, the higher the wakeup frequency.

Now when making the decision on whether to pull or not, pay attention to
the wakee with a high 'wakee_flips', pulling such a task may benefit
the wakee. Also imply that the waker will face cruel competition later,
it could be very cruel or very fast depends on the story behind
'wakee_flips', waker therefore suffers.

Furthermore, if waker also has a high 'wakee_flips', that implies that
multiple tasks rely on it, then waker's higher latency will damage all
of them, so pulling wakee seems to be a bad deal.

Thus, when 'waker->wakee_flips / wakee->wakee_flips' becomes
higher and higher, the cost of pulling seems to be worse and worse.

The patch therefore helps the wake-affine feature to stop its pulling
work when:

	wakee->wakee_flips > factor &&
	waker->wakee_flips > (factor * wakee->wakee_flips)

The 'factor' here is the number of CPUs in the current CPU's NUMA node,
so a bigger node will lead to more pulling since the trial becomes more
severe.

After applying the patch, pgbench shows up to 40% improvements and no regressions.

Tested with 12 cpu x86 server and tip 3.10.0-rc7.

The percentages in the final column highlight the areas with the biggest wins,
all other areas improved as well:

	pgbench		    base	smart

	| db_size | clients |  tps  |	|  tps  |
	+---------+---------+-------+   +-------+
	| 22 MB   |       1 | 10598 |   | 10796 |
	| 22 MB   |       2 | 21257 |   | 21336 |
	| 22 MB   |       4 | 41386 |   | 41622 |
	| 22 MB   |       8 | 51253 |   | 57932 |
	| 22 MB   |      12 | 48570 |   | 54000 |
	| 22 MB   |      16 | 46748 |   | 55982 | +19.75%
	| 22 MB   |      24 | 44346 |   | 55847 | +25.93%
	| 22 MB   |      32 | 43460 |   | 54614 | +25.66%
	| 7484 MB |       1 |  8951 |   |  9193 |
	| 7484 MB |       2 | 19233 |   | 19240 |
	| 7484 MB |       4 | 37239 |   | 37302 |
	| 7484 MB |       8 | 46087 |   | 50018 |
	| 7484 MB |      12 | 42054 |   | 48763 |
	| 7484 MB |      16 | 40765 |   | 51633 | +26.66%
	| 7484 MB |      24 | 37651 |   | 52377 | +39.11%
	| 7484 MB |      32 | 37056 |   | 51108 | +37.92%
	| 15 GB   |       1 |  8845 |   |  9104 |
	| 15 GB   |       2 | 19094 |   | 19162 |
	| 15 GB   |       4 | 36979 |   | 36983 |
	| 15 GB   |       8 | 46087 |   | 49977 |
	| 15 GB   |      12 | 41901 |   | 48591 |
	| 15 GB   |      16 | 40147 |   | 50651 | +26.16%
	| 15 GB   |      24 | 37250 |   | 52365 | +40.58%
	| 15 GB   |      32 | 36470 |   | 50015 | +37.14%

Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/51D50057.9000809@linux.vnet.ibm.com
[ Improved the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23 12:18:41 +02:00
Vladimir Davydov
685207963b sched: Move h_load calculation to task_h_load()
The bad thing about update_h_load(), which computes hierarchical load
factor for task groups, is that it is called for each task group in the
system before every load balancer run, and since rebalance can be
triggered very often, this function can eat really a lot of cpu time if
there are many cpu cgroups in the system.

Although the situation was improved significantly by commit a35b646
('sched, cgroup: Reduce rq->lock hold times for large cgroup
hierarchies'), the problem still can arise under some kinds of loads,
e.g. when cpus are switching from idle to busy and back very frequently.

For instance, when I start 1000 of processes that wake up every
millisecond on my 8 cpus host, 'top' and 'perf top' show:

Cpu(s): 17.8%us, 24.3%sy,  0.0%ni, 57.9%id,  0.0%wa,  0.0%hi,  0.0%si
Events: 243K cycles
  7.57%  [kernel]               [k] __schedule
  7.08%  [kernel]               [k] timerqueue_add
  6.13%  libc-2.12.so           [.] usleep

Then if I create 10000 *idle* cpu cgroups (no processes in them), cpu
usage increases significantly although the 'wakers' are still executing
in the root cpu cgroup:

Cpu(s): 19.1%us, 48.7%sy,  0.0%ni, 31.6%id,  0.0%wa,  0.0%hi,  0.7%si
Events: 230K cycles
 24.56%  [kernel]            [k] tg_load_down
  5.76%  [kernel]            [k] __schedule

This happens because this particular kind of load triggers 'new idle'
rebalance very frequently, which requires calling update_h_load(),
which, in turn, calls tg_load_down() for every *idle* cpu cgroup even
though it is absolutely useless, because idle cpu cgroups have no tasks
to pull.

This patch tries to improve the situation by making h_load calculation
proceed only when h_load is really necessary. To achieve this, it
substitutes update_h_load() with update_cfs_rq_h_load(), which computes
h_load only for a given cfs_rq and all its ascendants, and makes the
load balancer call this function whenever it considers if a task should
be pulled, i.e. it moves h_load calculations directly to task_h_load().
For h_load of the same cfs_rq not to be updated multiple times (in case
several tasks in the same cgroup are considered during the same balance
run), the patch keeps the time of the last h_load update for each cfs_rq
and breaks calculation when it finds h_load to be uptodate.

The benefit of it is that h_load is computed only for those cfs_rq's,
which really need it, in particular all idle task groups are skipped.
Although this, in fact, moves h_load calculation under rq lock, it
should not affect latency much, because the amount of work done under rq
lock while trying to pull tasks is limited by sched_nr_migrate.

After the patch applied with the setup described above (1000 wakers in
the root cgroup and 10000 idle cgroups), I get:

Cpu(s): 16.9%us, 24.8%sy,  0.0%ni, 58.4%id,  0.0%wa,  0.0%hi,  0.0%si
Events: 242K cycles
  7.57%  [kernel]                  [k] __schedule
  6.70%  [kernel]                  [k] timerqueue_add
  5.93%  libc-2.12.so              [.] usleep

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1373896159-1278-1-git-send-email-vdavydov@parallels.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23 12:18:41 +02:00
Peter Zijlstra
a5cdd40c98 perf: Update perf_event_type documentation
Due to a discussion with Adrian I had a good look at the perf_event_type record
layout and found the documentation to be somewhat unclear.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130716150907.GL23818@dyad.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23 12:17:08 +02:00
Davidlohr Bueso
ec83f425db mutex: Do not unnecessarily deal with waiters
Upon entering the slowpath, we immediately attempt to acquire
the lock by checking if it is already unlocked. If we are lucky
enough that this is the case, then we don't need to deal with
any waiter related logic.

Furthermore any checks for an empty wait_list are unnecessary as
we already know that count is non-negative and hence no one is
waiting for the lock.

Move the count check and xchg calls to be done before any
waiters are setup - including waiter debugging. Upon failure to
acquire the lock, the xchg sets the counter to 0, instead of -1
as it was originally. This can be done here since we set it back
to -1 right at the beginning of the loop so other waiters are
woken up when the lock is released.

When tested on a 8-socket (80 core) system against a vanilla
3.10-rc1 kernel, this patch provides some small performance
benefits (+2-6%). While it could be considered in the noise
level, the average percentages were stable across multiple runs
and no performance regressions were seen. Two big winners, for
small amounts of users (10-100), were the short and compute
workloads had a +19.36% and +%15.76% in jobs per minute.

Also change some break statements to 'goto slowpath', which IMO
makes a little more intuitive to read.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1372450398.2106.1.camel@buesod1.americas.hpqcorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23 11:48:37 +02:00
Ingo Molnar
b59f2b4d30 Linux 3.11-rc2
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Merge tag 'v3.11-rc2' into core/locking

Merge in Linux 3.11-rc2 before moving on with new work.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23 11:48:17 +02:00
Jiri Kosina
17f41571bb kprobes/x86: Call out into INT3 handler directly instead of using notifier
In fd4363fff3d96 ("x86: Introduce int3 (breakpoint)-based
instruction patching"), the mechanism that was introduced for
notifying alternatives code from int3 exception handler that and
exception occured was die_notifier.

This is however problematic, as early code might be using jump
labels even before the notifier registration has been performed,
which will then lead to an oops due to unhandled exception. One
of such occurences has been encountered by Fengguang:

 int3: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.11.0-rc1-01429-g04bf576 #8
 task: ffff88000da1b040 ti: ffff88000da1c000 task.ti: ffff88000da1c000
 RIP: 0010:[<ffffffff811098cc>]  [<ffffffff811098cc>] ttwu_do_wakeup+0x28/0x225
 RSP: 0000:ffff88000dd03f10  EFLAGS: 00000006
 RAX: 0000000000000000 RBX: ffff88000dd12940 RCX: ffffffff81769c40
 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000001
 RBP: ffff88000dd03f28 R08: ffffffff8176a8c0 R09: 0000000000000002
 R10: ffffffff810ff484 R11: ffff88000dd129e8 R12: ffff88000dbc90c0
 R13: ffff88000dbc90c0 R14: ffff88000da1dfd8 R15: ffff88000da1dfd8
 FS:  0000000000000000(0000) GS:ffff88000dd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 00000000ffffffff CR3: 0000000001c88000 CR4: 00000000000006e0
 Stack:
  ffff88000dd12940 ffff88000dbc90c0 ffff88000da1dfd8 ffff88000dd03f48
  ffffffff81109e2b ffff88000dd12940 0000000000000000 ffff88000dd03f68
  ffffffff81109e9e 0000000000000000 0000000000012940 ffff88000dd03f98
 Call Trace:
  <IRQ>
  [<ffffffff81109e2b>] ttwu_do_activate.constprop.56+0x6d/0x79
  [<ffffffff81109e9e>] sched_ttwu_pending+0x67/0x84
  [<ffffffff8110c845>] scheduler_ipi+0x15a/0x2b0
  [<ffffffff8104dfb4>] smp_reschedule_interrupt+0x38/0x41
  [<ffffffff8173bf5d>] reschedule_interrupt+0x6d/0x80
  <EOI>
  [<ffffffff810ff484>] ? __atomic_notifier_call_chain+0x5/0xc1
  [<ffffffff8105cc30>] ? native_safe_halt+0xd/0x16
  [<ffffffff81015f10>] default_idle+0x147/0x282
  [<ffffffff81017026>] arch_cpu_idle+0x3d/0x5d
  [<ffffffff81127d6a>] cpu_idle_loop+0x46d/0x5db
  [<ffffffff81127f5c>] cpu_startup_entry+0x84/0x84
  [<ffffffff8104f4f8>] start_secondary+0x3c8/0x3d5
  [...]

Fix this by directly calling poke_int3_handler() from the int3
exception handler (analogically to what ftrace has been doing
already), instead of relying on notifier, registration of which
might not have yet been finalized by the time of the first trap.

Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1307231007490.14024@pobox.suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23 10:12:57 +02:00
Linus Torvalds
b3a3a9c441 This contains fixes, optimizations and some clean ups
Some of the fixes need to go back to 3.10. They are minor, and deal mostly
 with incorrect ref counting in accessing event files.
 
 There was a couple of optimizations that should have perf perform a bit
 better when accessing trace events.
 
 And some various clean ups. Some of the clean ups are necessary to help
 in a fix to a theoretical race between opening a event file and
 deleting that event.
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Merge tag 'trace-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes and cleanups from Steven Rostedt:
 "This contains fixes, optimizations and some clean ups

  Some of the fixes need to go back to 3.10.  They are minor, and deal
  mostly with incorrect ref counting in accessing event files.

  There was a couple of optimizations that should have perf perform a
  bit better when accessing trace events.

  And some various clean ups.  Some of the clean ups are necessary to
  help in a fix to a theoretical race between opening a event file and
  deleting that event"

* tag 'trace-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Kill the unbalanced tr->ref++ in tracing_buffers_open()
  tracing: Kill trace_array->waiter
  tracing: Do not (ab)use trace_seq in event_id_read()
  tracing: Simplify the iteration logic in f_start/f_next
  tracing: Add ref_data to function and fgraph tracer structs
  tracing: Miscellaneous fixes for trace_array ref counting
  tracing: Fix error handling to ensure instances can always be removed
  tracing/kprobe: Wait for disabling all running kprobe handlers
  tracing/perf: Move the PERF_MAX_TRACE_SIZE check into perf_trace_buf_prepare()
  tracing/syscall: Avoid perf_trace_buf_*() if sys_data->perf_events is empty
  tracing/function: Avoid perf_trace_buf_*() if event_function.perf_events is empty
  tracing: Typo fix on ring buffer comments
  tracing: Use trace_seq_puts()/trace_seq_putc() where possible
  tracing: Use correct config guard CONFIG_STACK_TRACER
2013-07-22 19:07:24 -07:00
Baruch Siach
53c0352042 sched_clock: Fix integer overflow
The expression '(1 << 32)' happens to evaluate as 0 on ARM, but
it evaluates as 1 on xtensa and x86_64. This zeros sched_clock_mask,
and breaks sched_clock().

Set the type of 1 to 'unsigned long long' to get the value we need.

Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-07-22 16:24:22 -07:00
Peter Zijlstra
1e40c2edef mutex: Fix/document access-once assumption in mutex_can_spin_on_owner()
mutex_can_spin_on_owner() is technically broken in that it would
in theory allow the compiler to load lock->owner twice, seeing a
pointer first time and a NULL pointer the second time.

Linus pointed out that a compiler has to be seriously broken to
not compile this correctly - but nevertheless this change
is correct as it will better document the implementation.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Acked-by: Waiman Long <Waiman.Long@hp.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20130719183101.GA20909@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-22 10:33:39 +02:00
Kirill Tkhai
87e3c8ae1c sched/fair: Cleanup: remove duplicate variable declaration
cfs_rq is declared twice, fix it.

Also use 'se' instead of '&p->se'.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/169201374366727@web6d.yandex.ru
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-22 10:27:40 +02:00
Ingo Molnar
b24d6f4912 Linux 3.11-rc2
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Merge tag 'v3.11-rc2' into sched/core

Merge in Linux 3.11-rc2, to provide a post-merge-window development base.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-22 10:26:10 +02:00
Oleg Nesterov
e70e78e3c8 tracing: Kill the unbalanced tr->ref++ in tracing_buffers_open()
tracing_buffers_open() does trace_array_get() and then it wrongly
inrcements tr->ref again under trace_types_lock. This means that
every caller leaks trace_array:

	# cd /sys/kernel/debug/tracing/
	# mkdir instances/X
	# true < instances/X/per_cpu/cpu0/trace_pipe_raw
	# rmdir instances/X
	rmdir: failed to remove `instances/X': Device or resource busy

Link: http://lkml.kernel.org/r/20130719153644.GA18899@redhat.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: stable@vger.kernel.org # 3.10
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-19 14:32:22 -04:00
Linus Torvalds
b7356abb9f Power management and ACPI fixes for 3.11-rc2
- Two cpufreq commits from the 3.10 cycle introduced regressions.
   The first of them was buggy (it did way much more than it needed
   to do) and the second one attempted to fix an issue introduced by
   the first one.  Fixes from Srivatsa S Bhat revert both.
 
 - If autosleep triggers during system shutdown and the shutdown
   callbacks of some device drivers have been called already, it may
   crash the system.  Fix from Liu Shuo prevents that from happening
   by making try_to_suspend() check system_state.
 
 - The ACPI memory hotplug driver doesn't clear its driver_data on
   errors which may cause a NULL poiter dereference to happen later.
   Fix from Toshi Kani.
 
 - The ACPI namespace scanning code should not try to attach scan
   handlers to device objects that have them already, which may confuse
   things quite a bit, and it should rescan the whole namespace branch
   starting at the given node after receiving a bus check notify event
   even if the device at that particular node has been discovered
   already.  Fixes from Rafael J Wysocki.
 
 - New ACPI video blacklist entry for a system whose initial backlight
   setting from the BIOS doesn't make sense.  From Lan Tianyu.
 
 - Garbage string output avoindance for ACPI PNP from Liu Shuo.
 
 - Two Kconfig fixes for issues introduced recently in the s3c24xx
   cpufreq driver (when moving the driver to drivers/cpufreq) from
   Paul Bolle.
 
 - Trivial comment fix in pm_wakeup.h from Chanwoo Choi.
 
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Merge tag 'pm+acpi-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are fixes collected over the last week, most importnatly two
  cpufreq reverts fixing regressions introduced in 3.10, an autoseelp
  fix preventing systems using it from crashing during shutdown and two
  ACPI scan fixes related to hotplug.

  Specifics:

   - Two cpufreq commits from the 3.10 cycle introduced regressions.
     The first of them was buggy (it did way much more than it needed to
     do) and the second one attempted to fix an issue introduced by the
     first one.  Fixes from Srivatsa S Bhat revert both.

   - If autosleep triggers during system shutdown and the shutdown
     callbacks of some device drivers have been called already, it may
     crash the system.  Fix from Liu Shuo prevents that from happening
     by making try_to_suspend() check system_state.

   - The ACPI memory hotplug driver doesn't clear its driver_data on
     errors which may cause a NULL poiter dereference to happen later.
     Fix from Toshi Kani.

   - The ACPI namespace scanning code should not try to attach scan
     handlers to device objects that have them already, which may
     confuse things quite a bit, and it should rescan the whole
     namespace branch starting at the given node after receiving a bus
     check notify event even if the device at that particular node has
     been discovered already.  Fixes from Rafael J Wysocki.

   - New ACPI video blacklist entry for a system whose initial backlight
     setting from the BIOS doesn't make sense.  From Lan Tianyu.

   - Garbage string output avoindance for ACPI PNP from Liu Shuo.

   - Two Kconfig fixes for issues introduced recently in the s3c24xx
     cpufreq driver (when moving the driver to drivers/cpufreq) from
     Paul Bolle.

   - Trivial comment fix in pm_wakeup.h from Chanwoo Choi"

* tag 'pm+acpi-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / video: ignore BIOS initial backlight value for Fujitsu E753
  PNP / ACPI: avoid garbage in resource name
  cpufreq: Revert commit 2f7021a8 to fix CPU hotplug regression
  cpufreq: s3c24xx: fix "depends on ARM_S3C24XX" in Kconfig
  cpufreq: s3c24xx: rename CONFIG_CPU_FREQ_S3C24XX_DEBUGFS
  PM / Sleep: Fix comment typo in pm_wakeup.h
  PM / Sleep: avoid 'autosleep' in shutdown progress
  cpufreq: Revert commit a66b2e to fix suspend/resume regression
  ACPI / memhotplug: Fix a stale pointer in error path
  ACPI / scan: Always call acpi_bus_scan() for bus check notifications
  ACPI / scan: Do not try to attach scan handlers to devices having them
2013-07-19 09:59:06 -07:00
Oleg Nesterov
a644a7e958 tracing: Kill trace_array->waiter
Trivial. trace_array->waiter has no users since 6eaaa5d5
"tracing/core: use appropriate waiting on trace_pipe".

Link: http://lkml.kernel.org/r/20130719142036.GA1594@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-19 10:56:02 -04:00
Ingo Molnar
9bb15425c3 Merge branch 'x86/jumplabel' into perf/core
Upcoming kprobes patches rely on the int3 code-patching machinery introduced by:

   fd4363fff3d9 x86: Introduce int3 (breakpoint)-based instruction patching

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-19 09:55:00 +02:00
Ingo Molnar
e43fff2b98 Merge branch 'linus' into perf/core
Merge in a v3.11-rc1-ish branch to go from v3.10 based development
to a v3.11 based one.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-19 09:34:42 +02:00
Oleg Nesterov
cd458ba9d5 tracing: Do not (ab)use trace_seq in event_id_read()
event_id_read() has no reason to kmalloc "struct trace_seq"
(more than PAGE_SIZE!), it can use a small buffer instead.

Note: "if (*ppos) return 0" looks strange and even wrong,
simple_read_from_buffer() handles ppos != 0 case corrrectly.

And it seems that almost every user of trace_seq in this file
should be converted too. Unless you use seq_open(), trace_seq
buys nothing compared to the raw buffer, but it needs a bit
more memory and code.

Link: http://lkml.kernel.org/r/20130718184712.GA4786@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:33 -04:00
Oleg Nesterov
7710b63995 tracing: Simplify the iteration logic in f_start/f_next
f_next() looks overcomplicated, and it is not strictly correct
even if this doesn't matter.

Say, FORMAT_FIELD_SEPERATOR should not return NULL (means EOF)
if trace_get_fields() returns an empty list, we should simply
advance to FORMAT_PRINTFMT as we do when we find the end of list.

1. Change f_next() to return "struct list_head *" rather than
   "ftrace_event_field *", and change f_show() to do list_entry().

   This simplifies the code a bit, only f_show() needs to know
   about ftrace_event_field, and f_next() can play with ->prev
   directly

2. Change f_next() to not play with ->prev / return inside the
   switch() statement. It can simply set node = head/common_head,
   the prev-or-advance-to-the-next-magic below does all work.

While at it. f_start() looks overcomplicated too. I don't think
*pos == 0 makes sense as a separate case, just change this code
to do "while" instead of "do/while".

The patch also moves f_start() down, close to f_stop(). This is
purely cosmetic, just to make the locking added by the next patch
more clear/visible.

Link: http://lkml.kernel.org/r/20130718184710.GA4783@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:32 -04:00
Steven Rostedt (Red Hat)
8f76899339 tracing: Add ref_data to function and fgraph tracer structs
The selftest for function and function graph tracers are defined as
__init, as they are only executed at boot up. The "tracer" structs
that are associated to those tracers are not setup as __init as they
are used after boot. To stop mismatch warnings, those structures
need to be annotated with __ref_data.

Currently, the tracer structures are defined to __read_mostly, as they
do not really change. But in the future they should be converted to
consts, but that will take a little work because they have a "next"
pointer that gets updated when they are registered. That will have to
wait till the next major release.

Link: http://lkml.kernel.org/r/1373596735.17876.84.camel@gandalf.local.home

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:31 -04:00
Alexander Z Lam
f77d09a384 tracing: Miscellaneous fixes for trace_array ref counting
Some error paths did not handle ref counting properly, and some trace files need
ref counting.

Link: http://lkml.kernel.org/r/1374171524-11948-1-git-send-email-azl@google.com

Cc: stable@vger.kernel.org # 3.10
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Alexander Z Lam <lambchop468@gmail.com>
Signed-off-by: Alexander Z Lam <azl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:30 -04:00
Alexander Z Lam
609e85a70b tracing: Fix error handling to ensure instances can always be removed
Remove debugfs directories for tracing instances during creation if an error
occurs causing the trace_array for that instance to not be added to
ftrace_trace_arrays. If the directory continues to exist after the error, it
cannot be removed because the respective trace_array is not in
ftrace_trace_arrays.

Link: http://lkml.kernel.org/r/1373502874-1706-2-git-send-email-azl@google.com

Cc: stable@vger.kernel.org # 3.10
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Alexander Z Lam <lambchop468@gmail.com>
Signed-off-by: Alexander Z Lam <azl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:30 -04:00
Masami Hiramatsu
a232e270dc tracing/kprobe: Wait for disabling all running kprobe handlers
Wait for disabling all running kprobe handlers when a kprobe
event is disabled, since the caller, trace_remove_event_call()
supposes that a removing event is disabled completely by
disabling the event.
With this change, ftrace can ensure that there is no running
event handlers after disabling it.

Link: http://lkml.kernel.org/r/20130709093526.20138.93100.stgit@mhiramat-M0-7522

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:29 -04:00
Oleg Nesterov
cd92bf61d6 tracing/perf: Move the PERF_MAX_TRACE_SIZE check into perf_trace_buf_prepare()
Every perf_trace_buf_prepare() caller does
WARN_ONCE(size > PERF_MAX_TRACE_SIZE, message) and "message" is
almost the same.

Shift this WARN_ONCE() into perf_trace_buf_prepare(). This changes
the meaning of _ONCE, but I think this is fine.

	- 4947014 2932448 10104832  17984294  1126b26 vmlinux
	+ 4948422 2932448 10104832  17985702  11270a6 vmlinux

on my build.

Link: http://lkml.kernel.org/r/20130617170211.GA19813@redhat.com

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:28 -04:00
Oleg Nesterov
421c7860c6 tracing/syscall: Avoid perf_trace_buf_*() if sys_data->perf_events is empty
perf_trace_buf_prepare() + perf_trace_buf_submit(head, task => NULL)
make no sense if hlist_empty(head). Change perf_syscall_enter/exit()
to check sys_data->{enter,exit}_event->perf_events beforehand.

Link: http://lkml.kernel.org/r/20130617170207.GA19806@redhat.com

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:28 -04:00
Oleg Nesterov
b8ebfd3f71 tracing/function: Avoid perf_trace_buf_*() if event_function.perf_events is empty
perf_trace_buf_prepare() + perf_trace_buf_submit(head, task => NULL)
make no sense if hlist_empty(head). Change perf_ftrace_function_call()
to check event_function.perf_events beforehand.

Link: http://lkml.kernel.org/r/20130617170204.GA19803@redhat.com

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:27 -04:00
zhangwei(Jovi)
d611851b42 tracing: Typo fix on ring buffer comments
There have some mismatch between comments with
real function name, update it.

This patch also add some missed function arguments
description.

Link: http://lkml.kernel.org/r/51E3B3B2.4080307@huawei.com

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:31:26 -04:00
zhangwei(Jovi)
146c3442f2 tracing: Use trace_seq_puts()/trace_seq_putc() where possible
For string without format specifiers, use trace_seq_puts()
or trace_seq_putc().

Link: http://lkml.kernel.org/r/51E3B3AC.1000605@huawei.com

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
[ fixed a trace_seq_putc(s, " ") to trace_seq_putc(s, ' ') ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-18 21:30:36 -04:00
Linus Torvalds
7a62711aac Driver core patches for 3.11-rc2
Here are some driver core patches for 3.11-rc2.  They aren't really
 bugfixes, but a bunch of new helper macros for drivers to properly
 create attribute groups, which drivers and subsystems need to fix up a
 ton of race issues with incorrectly creating sysfs files (binary and
 normal) after userspace has been told that the device is present.
 
 Also here is the ability to create binary files as attribute groups, to
 solve that race condition, which was impossible to do before this, so
 that's my fault the drivers were broken.
 
 The majority of the .c changes is indenting and moving code around a
 bit.  It affects no existing code, but allows the large backlog of 70+
 patches that I already have created to start flowing into the different
 subtrees, instead of having to live in my driver-core tree, causing
 merge nightmares in linux-next for the next few months.
 
 These were finalized too late for the -rc1 merge window, which is why
 they were didn't make that pull request, testing and review from others
 didn't happen until a few weeks ago, and then there's the whole
 distraction of the past few days, which prevented these from getting to
 you sooner, sorry about that.
 
 Oh, and there's a bugfix for the documentation build warning in here as
 well.  All of these have been in linux-next this week, with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core patches from Greg KH:
 "Here are some driver core patches for 3.11-rc2.  They aren't really
  bugfixes, but a bunch of new helper macros for drivers to properly
  create attribute groups, which drivers and subsystems need to fix up a
  ton of race issues with incorrectly creating sysfs files (binary and
  normal) after userspace has been told that the device is present.

  Also here is the ability to create binary files as attribute groups,
  to solve that race condition, which was impossible to do before this,
  so that's my fault the drivers were broken.

  The majority of the .c changes is indenting and moving code around a
  bit.  It affects no existing code, but allows the large backlog of 70+
  patches that I already have created to start flowing into the
  different subtrees, instead of having to live in my driver-core tree,
  causing merge nightmares in linux-next for the next few months.

  These were finalized too late for the -rc1 merge window, which is why
  they were didn't make that pull request, testing and review from
  others didn't happen until a few weeks ago, and then there's the whole
  distraction of the past few days, which prevented these from getting
  to you sooner, sorry about that.

  Oh, and there's a bugfix for the documentation build warning in here
  as well.  All of these have been in linux-next this week, with no
  reported problems"

* tag 'driver-core-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver-core: fix new kernel-doc warning in base/platform.c
  sysfs: use file mode defines from stat.h
  sysfs: add more helper macro's for (bin_)attribute(_groups)
  driver core: add default groups to struct class
  driver core: Introduce device_create_groups
  sysfs: prevent warning when only using binary attributes
  sysfs: add support for binary attributes in groups
  driver core: device.h: add RW and RO attribute macros
  sysfs.h: add BIN_ATTR macro
  sysfs.h: add ATTRIBUTE_GROUPS() macro
  sysfs.h: add __ATTR_RW() macro
2013-07-18 12:48:40 -07:00
Yacine Belkadi
e69f61862a sched: Fix some kernel-doc warnings
When building the htmldocs (in verbose mode), scripts/kernel-doc
reports the follwing type of warnings:

  Warning(kernel/sched/core.c:936): No description found for return value of 'task_curr'
  ...

Fix those by:

 - adding the missing descriptions
 - using "Return" sections for the descriptions

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1373654747-2389-1-git-send-email-yacine.belkadi.1@gmail.com
[ While at it, fix the cpupri_set() explanation. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-18 09:58:21 +02:00
Jiri Kosina
fd4363fff3 x86: Introduce int3 (breakpoint)-based instruction patching
Introduce a method for run-time instruction patching on a live SMP kernel
based on int3 breakpoint, completely avoiding the need for stop_machine().

The way this is achieved:

	- add a int3 trap to the address that will be patched
	- sync cores
	- update all but the first byte of the patched range
	- sync cores
	- replace the first byte (int3) by the first byte of
	  replacing opcode
	- sync cores

According to

	http://lkml.indiana.edu/hypermail/linux/kernel/1001.1/01530.html

synchronization after replacing "all but first" instructions should not
be necessary (on Intel hardware), as the syncing after the subsequent
patching of the first byte provides enough safety.
But there's not only Intel HW out there, and we'd rather be on a safe
side.

If any CPU instruction execution would collide with the patching,
it'd be trapped by the int3 breakpoint and redirected to the provided
"handler" (which would typically mean just skipping over the patched
region, acting as "nop" has been there, in case we are doing nop -> jump
and jump -> nop transitions).

Ftrace has been using this very technique since 08d636b ("ftrace/x86:
Have arch x86_64 use breakpoints instead of stop machine") for ages
already, and jump labels are another obvious potential user of this.

Based on activities of Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
a few years ago.

Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1307121102440.29788@pobox.suse.cz
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-07-16 17:55:29 -07:00
Greg Kroah-Hartman
b9b3259746 sysfs.h: add __ATTR_RW() macro
A number of parts of the kernel created their own version of this, might
as well have the sysfs core provide it instead.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16 10:57:36 -07:00
Tejun Heo
a698b4488a cgroup: remove gratuituous BUG_ON()s from rebind_subsystems()
rebind_subsystems() performs santiy checks even on subsystems which
aren't specified to be added or removed and the checks aren't all that
useful given that these are in a very cold path while the violations
they check would trip up in much hotter paths.

Let's remove these from rebind_subsystems().

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-07-16 05:28:24 -06:00
Tejun Heo
1d5be6b287 cgroup: move module ref handling into rebind_subsystems()
Module ref handling in cgroup is rather weird.
parse_cgroupfs_options() grabs all the modules for the specified
subsystems.  A module ref is kept if the specified subsystem is newly
bound to the hierarchy.  If not, or the operation fails, the refs are
dropped.  This scatters module ref handling across multiple functions
making it difficult to track.  It also make the function nasty to use
for dynamic subsystem binding which is necessary for the planned
unified hierarchy.

There's nothing which requires the subsystem modules to be pinned
between parse_cgroupfs_options() and rebind_subsystems() in both mount
and remount paths.  parse_cgroupfs_options() can just parse and
rebind_subsystems() can handle pinning the subsystems that it wants to
bind, which is a natural part of its task - binding - anyway.

Move module ref handling into rebind_subsystems() which makes the code
a lot simpler - modules are gotten iff it's gonna be bound and put iff
unbound or binding fails.

v2: Li pointed out that if a controller module is unloaded between
    parsing and binding, rebind_subsystems() won't notice the missing
    controller as it only iterates through existing controllers.  Fix
    it by updating rebind_subsystems() to compare @added_mask to
    @pinned and fail with -ENOENT if they don't match.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-07-16 05:28:24 -06:00
zhangwei(Jovi)
991821c86c tracing: Use correct config guard CONFIG_STACK_TRACER
We should use CONFIG_STACK_TRACER to guard readme text
of stack tracer related file, not CONFIG_STACKTRACE.

Link: http://lkml.kernel.org/r/51E3B3A2.8080609@huawei.com

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-15 12:38:10 -04:00
Paul Gortmaker
0db0628d90 kernel: delete __cpuinit usage from all core kernel files
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the uses of the __cpuinit macros from C files in
the core kernel directories (kernel, init, lib, mm, and include)
that don't really have a specific maintainer.

[1] https://lkml.org/lkml/2013/5/20/589

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-07-14 19:36:59 -04:00
Paul Gortmaker
49fb4c6290 rcu: delete __cpuinit usage from all rcu files
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the drivers/rcu uses of the __cpuinit macros
from all C files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@freedesktop.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-07-14 19:36:58 -04:00
Liu ShuoX
e5248a111b PM / Sleep: avoid 'autosleep' in shutdown progress
Prevent automatic system suspend from happening during system
shutdown by making try_to_suspend() check system_state and return
immediately if it is not SYSTEM_RUNNING.

This prevents the following breakage from happening (scenario from
Zhang Yanmin):

 Kernel starts shutdown and calls all device driver's shutdown
 callback.  When a driver's shutdown is called, the last wakelock is
 released and suspend-to-ram starts.  However, as some driver's shut
 down callbacks already shut down devices and disabled runtime pm,
 the suspend-to-ram calls driver's suspend callback without noticing
 that device is already off and causes crash.

[rjw: Changelog]
Signed-off-by: Liu ShuoX <shuox.liu@intel.com>
Cc: 3.5+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-15 01:31:37 +02:00
Linus Torvalds
41d9884c44 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs stuff from Al Viro:
 "O_TMPFILE ABI changes, Oleg's fput() series, misc cleanups, including
  making simple_lookup() usable for filesystems with non-NULL s_d_op,
  which allows us to get rid of quite a bit of ugliness"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  sunrpc: now we can just set ->s_d_op
  cgroup: we can use simple_lookup() now
  efivarfs: we can use simple_lookup() now
  make simple_lookup() usable for filesystems that set ->s_d_op
  configfs: don't open-code d_alloc_name()
  __rpc_lookup_create_exclusive: pass string instead of qstr
  rpc_create_*_dir: don't bother with qstr
  llist: llist_add() can use llist_add_batch()
  llist: fix/simplify llist_add() and llist_add_batch()
  fput: turn "list_head delayed_fput_list" into llist_head
  fs/file_table.c:fput(): add comment
  Safer ABI for O_TMPFILE
2013-07-14 11:42:26 -07:00
Al Viro
786e1448d9 cgroup: we can use simple_lookup() now
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-14 17:50:23 +04:00
Linus Torvalds
f8acc450e1 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
 "Fix a potential deadlock versus hrtimers"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix HRTICK
2013-07-13 15:37:57 -07:00
Linus Torvalds
505608d2b9 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 - core fix for missing round up in the generic irq chip implementation
 - new irq chip for MOXA SoCs
 - a few fixes and cleanups in the irqchip drivers

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Add support for MOXA ART SoCs
  genirq: generic chip: Use DIV_ROUND_UP to calculate numchips
  irqchip: nvic: Fix wrong num_ct argument for irq_alloc_domain_generic_chips()
  irqchip: sun4i: Staticize sun4i_irq_ack()
  irqchip: vt8500: Staticize local symbols
2013-07-13 15:37:30 -07:00
Linus Torvalds
0da2736686 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 - watchdog fixes for full dynticks
 - improved debug output for full dynticks
 - remove an obsolete full dynticks check
 - two ARM SoC clocksource drivers for sharing across SoCs
 - tick broadcast fix for CPU hotplug

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick: broadcast: Check broadcast mode on CPU hotplug
  clocksource: arm_global_timer: Add ARM global timer support
  clocksource: Add Marvell Orion SoC timer
  nohz: Remove obsolete check for full dynticks CPUs to be RCU nocbs
  watchdog: Boot-disable by default on full dynticks
  watchdog: Rename confusing state variable
  watchdog: Register / unregister watchdog kthreads on sysctl control
  nohz: Warn if the machine can not perform nohz_full
2013-07-13 15:36:09 -07:00
Linus Torvalds
560ae37178 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 - fix for do_div() abuse on x86
 - locking fix in perf core
 - a pile of (build) fixes and cleanups in perf tools

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  perf/x86: Fix incorrect use of do_div() in NMI warning
  perf: Fix perf_lock_task_context() vs RCU
  perf: Remove WARN_ON_ONCE() check in __perf_event_enable() for valid scenario
  perf: Clone child context from parent context pmu
  perf script: Fix broken include in Context.xs
  perf tools: Fix -ldw/-lelf link test when static linking
  perf tools: Revert regression in configuration of Python support
  perf tools: Fix perf version generation
  perf stat: Fix per-socket output bug for uncore events
  perf symbols: Fix vdso list searching
  perf evsel: Fix missing increment in sample parsing
  perf tools: Update symbol_conf.nr_events when processing attribute events
  perf tools: Fix new_term() missing free on error path
  perf tools: Fix parse_events_terms() segfault on error path
  perf evsel: Fix count parameter to read call in event_format__new
  perf tools: fix a typo of a Power7 event name
  perf tools: Fix -x/--exclude-other option for report command
  perf evlist: Enhance perf_evlist__start_workload()
  perf record: Remove -f/--force option
  perf record: Remove -A/--append option
  ...
2013-07-13 15:35:47 -07:00
Linus Torvalds
4fa109b130 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking updates from Thomas Gleixner:
 "Header cleanup as requested by Linus"

(This is the "don't include support for ww_mutex in a header file that
everybody wants, when almost nobody wants the ww part" change)

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mutex: Move ww_mutex definitions to ww_mutex.h
2013-07-13 15:35:12 -07:00