In 53b5e2f generic cgroup subsystem permission checks have been added.
When this is been done within procs_write an empty taskset is added to
the tasks css set. When a task later on migrates to a new group we see a
dmesg warning cause the mg_node isn't empty (cgroup.c:2086). Cause this
happens all the time this spams dmesg.
I am not really familiar with this code, but it looks to me like adding
the taskset is just a temporary action in this context. Therefore this
taskset should be removed after the actual check. This is what this fix
does.
This problem was seen and the fix tested on x86 using l-mr1 and master.
Change-Id: I9894d39e8b5692ef65149002b07e65a84a33ffea
Signed-off-by: Christian Poetzsch <christian.potzsch@imgtec.com>
- Return -EINVAL when cgroups support isn't enabled
- Add allow_attach callback in CPU cgroups
Change-Id: Id3360b4a39919524fc4b6fcbd44fa2050009f000
Signed-off-by: Rom Lemarchand <romlem@android.com>
Rather than using explicit euid == 0 checks when trying to move
tasks into a cgroup via CFS, move permission checks into each
specific cgroup subsystem. If a subsystem does not specify a
'allow_attach' handler, then we fall back to doing our checks
the old way.
Use the 'allow_attach' handler for the 'cpu' cgroup to allow
non-root processes to add arbitrary processes to a 'cpu' cgroup
if it has the CAP_SYS_NICE capability set.
This version of the patch adds a 'allow_attach' handler instead
of reusing the 'can_attach' handler. If the 'can_attach' handler
is reused, a new cgroup that implements 'can_attach' but not
the permission checks could end up with no permission checks
at all.
Change-Id: Icfa950aa9321d1ceba362061d32dc7dfa2c64f0c
Original-Author: San Mehat <san@google.com>
Signed-off-by: Colin Cross <ccross@android.com>
move cpu_cgroup_allow_attach to a common subsys_cgroup_allow_attach.
This allows any process with CAP_SYS_NICE to move tasks across cgroups if
they use this function as their allow_attach handler.
Bug: 18260435
Change-Id: I6bb4933d07e889d0dc39e33b4e71320c34a2c90f
Signed-off-by: Rom Lemarchand <romlem@android.com>
Suspend time reporting Change-Id: I2cb9a9408a5fd12166aaec11b935a0fd6a408c63
(Power: Report suspend times from last_suspend_time), is broken on 3.16+
kernels because get_xtime_and_monotonic_and_sleep_offset() hrtimer helper
routine is removed from kernel timekeeping.
The replacement helper routines ktime_get_update_offsets_{tick,now}()
are private to core kernel timekeeping so we can't use them, hence using
ktime_get() and ktime_get_boottime() instead and sampling the time twice.
Idea is to use Monotonic boottime offset to calculate total time spent
in last suspend state and CLOCK_MONOTONIC to calculate time spent in
last suspend-resume process.
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
This node epxorts two values separated by space.
From left to right:
1. time spent in suspend/resume process
2. time spent sleep in suspend state
Change-Id: I2cb9a9408a5fd12166aaec11b935a0fd6a408c63
Remove the HAS_WAKELOCK config as it doesn't seem to have been used in
the 3.10 or 3.14 kernels.
Add some Documentation to CONFIG_WAKELOCK so that it is selectable and
can be disabled is desired.
Signed-off-by: Dylan Reid <dgreid@chromium.org>
This unbreaks the build on architectures such as um that do not
support CONFIG_PM_SLEEP.
Change-Id: Ia846ed0a7fca1d762ececad20748d23610e8544f
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Wakeup reason is set before driver resume handlers are called.
It is cleared before driver suspend handlers are called, on
PM_SUSPEND_PREPARE.
Change-Id: I04218c9b0c115a7877e8029c73e6679ff82e0aa4
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
Extends the last_resume_reason to log suspend abort reason. The abort
reasons will have "Abort:" appended at the start to distinguish itself
from the resume reason.
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Change-Id: I3207f1844e3d87c706dfc298fb10e1c648814c5f
On x86, irq_count conflicts with a declaration in
arch/x86/include/asm/processor.h
Change-Id: I3e4fde0ff64ef59ff5ed2adc0ea3a644641ee0b7
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Ensure the array for the wakeup reason IRQs does not overflow.
Change-Id: Iddc57a3aeb1888f39d4e7b004164611803a4d37c
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
(cherry picked from commit b5ea40cdfcf38296535f931a7e5e7bf47b6fad7f)
Add API log_wakeup_reason() and expose it to userspace via sysfs path
/sys/kernel/wakeup_reasons/last_resume_reason
Change-Id: I81addaf420f1338255c5d0638b0d244a99d777d1
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Add ftrace event trace_sched_cpu_hotplug to track cpu
hot-add and hot-remove events.
This is useful in a variety of power, performance and
debug analysis scenarios.
Change-Id: I5d202c7a229ffacc3aafb7cf9afee0b0ee7b0931
Signed-off-by: Arun Bharadwaj <abharadw@codeaurora.org>
Add the 'funcgraph-flat' option to the function_graph tracer to use the default
trace printing format rather than the hierarchical formatting normally used.
Change-Id: If2900bfb86e6f8f51379f56da4f6fabafa630909
Signed-off-by: Jamie Gennis <jgennis@google.com>
The tgids are tracked along side the saved_cmdlines tracking, and can be
included in trace output by enabling the 'print-tgid' trace option. This is
useful when doing post-processing of the trace data, as it allows events to be
grouped by tgid.
Change-Id: I52ed04c3a8ca7fddbb868b792ce5d21ceb76250e
Signed-off-by: Jamie Gennis <jgennis@google.com>
Move the x86_64 idle notifiers originally by Andi Kleen and Venkatesh
Pallipadi to generic.
Change-Id: Idf29cda15be151f494ff245933c12462643388d5
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Decare war on uninterruptible sleep. Add a tracepoint which
walks the kernel stack and dumps the first non-scheduler function
called before the scheduler is invoked.
Change-Id: I19e965d5206329360a92cbfe2afcc8c30f65c229
Signed-off-by: Riley Andrews <riandrews@google.com>
kdb expects carriage returns through the serial port to terminate
commands. Modify it to accept the first seen carriage return or
new line as a terminator, but not treat \r\n as two terminators.
Change-Id: I06166017e7703d24310eefcb71c3a7d427088db7
Signed-off-by: Colin Cross <ccross@android.com>
Pull perf fixes from Ingo Molnar:
"Two core subsystem fixes, plus a handful of tooling fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix race in swevent hash
perf: Fix race in perf_event_exec()
perf list: Robustify event printing routine
perf list: Add support for PERF_COUNT_SW_BPF_OUT
perf hists browser: Fix segfault if use symbol filter in cmdline
perf hists browser: Reset selection when refresh
perf hists browser: Add NULL pointer check to prevent crash
perf buildid-list: Fix return value of perf buildid-list -k
perf buildid-list: Show running kernel build id fix
ftrace_module_init() and do_init_module() that the allocations made
in ftrace_module_init() will not be freed, resulting in a memory leak.
The solution is to call ftrace_release_mod() on the failing module in
the fail path befor do_init_module() is called. This will remove any
allocations made for that module, and nothing if ftrace_module_init()
wasn't called yet for that module.
Note, once do_init_module() is called, the MODULE_GOING notifiers are
called for the failed module, which calls into the ftrace code to do the
proper clean up (basically calling ftrace_release_mod()).
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Merge tag 'trace-v4.4-rc4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace fix from Steven Rostedt:
"PeiyangX Qiu reported that if a module fails to load between calling
ftrace_module_init() and do_init_module() that the allocations made in
ftrace_module_init() will not be freed, resulting in a memory leak.
The solution is to call ftrace_release_mod() on the failing module in
the fail path befor do_init_module() is called. This will remove any
allocations made for that module, and nothing if ftrace_module_init()
wasn't called yet for that module.
Note, once do_init_module() is called, the MODULE_GOING notifiers are
called for the failed module, which calls into the ftrace code to do
the proper clean up (basically calling ftrace_release_mod())"
* tag 'trace-v4.4-rc4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/module: Call clean up function when module init fails early
If the module init code fails after calling ftrace_module_init() and before
calling do_init_module(), we can suffer from a memory leak. This is because
ftrace_module_init() allocates pages to store the locations that ftrace
hooks are placed in the module text. If do_init_module() fails, it still
calls the MODULE_GOING notifiers which will tell ftrace to do a clean up of
the pages it allocated for the module. But if load_module() fails before
then, the pages allocated by ftrace_module_init() will never be freed.
Call ftrace_release_mod() on the module if load_module() fails before
getting to do_init_module().
Link: http://lkml.kernel.org/r/567CEA31.1070507@intel.com
Reported-by: "Qiu, PeiyangX" <peiyangx.qiu@intel.com>
Fixes: a949ae560a "ftrace/module: Hardcode ftrace_module_init() call into load_module()"
Cc: stable@vger.kernel.org # v2.6.38+
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In the following commit:
7675104990 ("sched: Implement lockless wake-queues")
we gained lockless wake-queues.
The -RT kernel managed to lockup itself with those. There could be multiple
attempts for task X to enqueue it for a wakeup _even_ if task X is already
running.
The reason is that task X could be runnable but not yet on CPU. The the
task performing the wakeup did not leave the CPU it could performe
multiple wakeups.
With the proper timming task X could be running and enqueued for a
wakeup. If this happens while X is performing a fork() then its its
child will have a !NULL `wake_q` member copied.
This is not a problem as long as the child task does not participate in
lockless wakeups :)
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 7675104990 ("sched: Implement lockless wake-queues")
Link: http://lkml.kernel.org/r/20151221171710.GA5499@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Make 'r' 64-bit type to avoid overflow in 'r * LOAD_AVG_MAX'
on 32-bit systems:
UBSAN: Undefined behaviour in kernel/sched/fair.c:2785:18
signed integer overflow:
87950 * 47742 cannot be represented in type 'int'
The most likely effect of this bug are bad load average numbers
resulting in weird scheduling. It's also likely that this can
persist for a longer time - until the system goes idle for
a long time so that all load avg numbers get reset.
[ This is the CFS load average metric, not the procfs output, which
is separate. ]
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 9d89c257df ("sched/fair: Rewrite runnable load and utilization average tracking")
Link: http://lkml.kernel.org/r/1450097243-30137-1-git-send-email-aryabinin@virtuozzo.com
[ Improved the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There's a race on CPU unplug where we free the swevent hash array
while it can still have events on. This will result in a
use-after-free which is BAD.
Simply do not free the hash array on unplug. This leaves the thing
around and no use-after-free takes place.
When the last swevent dies, we do a for_each_possible_cpu() iteration
anyway to clean these up, at which time we'll free it, so no leakage
will occur.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1. The recordmcount change had an output that used sprintf() (incorrectly)
when it should have been a fprintf() to stderr.
2. The printk_formats file could crash if someone added a trace_printk()
in the core kernel, and also added one in a module. This does not
affect production kernels. Only kernels where developers add trace_printk()
for debugging can crash.
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Merge tag 'trace-v4.4-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Two more fixes:
1. The recordmcount change had an output that used sprintf()
(incorrectly) when it should have been a fprintf() to stderr.
2. The printk_formats file could crash if someone added a
trace_printk() in the core kernel, and also added one in a module.
This does not affect production kernels. Only kernels where
developers add trace_printk() for debugging can crash"
* tag 'trace-v4.4-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix setting of start_index in find_next()
ftrace/scripts: Fix incorrect use of sprintf in recordmcount
When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel
panic at t_show.
general protection fault: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 2957 Comm: sh Tainted: G W O 3.14.55-x86_64-01062-gd4acdc7 #2
RIP: 0010:[<ffffffff811375b2>]
[<ffffffff811375b2>] t_show+0x22/0xe0
RSP: 0000:ffff88002b4ebe80 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1
RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec
R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0
R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570
FS: 0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0
Call Trace:
[<ffffffff811dc076>] seq_read+0x2f6/0x3e0
[<ffffffff811b749b>] vfs_read+0x9b/0x160
[<ffffffff811b7f69>] SyS_read+0x49/0xb0
[<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13
---[ end trace 5bd9eb630614861e ]---
Kernel panic - not syncing: Fatal exception
When the first time find_next calls find_next_mod_format, it should
iterate the trace_bprintk_fmt_list to find the first print format of
the module. However in current code, start_index is smaller than *pos
at first, and code will not iterate the list. Latter container_of will
get the wrong address with former v, which will cause mod_fmt be a
meaningless object and so is the returned mod_fmt->fmt.
This patch will fix it by correcting the start_index. After fixed,
when the first time calls find_next_mod_format, start_index will be
equal to *pos, and code will iterate the trace_bprintk_fmt_list to
get the right module printk format, so is the returned mod_fmt->fmt.
Link: http://lkml.kernel.org/r/5684B900.9000309@intel.com
Cc: stable@vger.kernel.org # 3.12+
Fixes: 102c9323c3 "tracing: Add __tracepoint_string() to export string pointers"
Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The Cavium guys reported a soft lockup on their arm64 machine, caused by
commit c55a6ffa62 ("locking/osq: Relax atomic semantics"):
mutex_optimistic_spin+0x9c/0x1d0
__mutex_lock_slowpath+0x44/0x158
mutex_lock+0x54/0x58
kernfs_iop_permission+0x38/0x70
__inode_permission+0x88/0xd8
inode_permission+0x30/0x6c
link_path_walk+0x68/0x4d4
path_openat+0xb4/0x2bc
do_filp_open+0x74/0xd0
do_sys_open+0x14c/0x228
SyS_openat+0x3c/0x48
el0_svc_naked+0x24/0x28
This is because in osq_lock we initialise the node for the current CPU:
node->locked = 0;
node->next = NULL;
node->cpu = curr;
and then publish the current CPU in the lock tail:
old = atomic_xchg_acquire(&lock->tail, curr);
Once the update to lock->tail is visible to another CPU, the node is
then live and can be both read and updated by concurrent lockers.
Unfortunately, the ACQUIRE semantics of the xchg operation mean that
there is no guarantee the contents of the node will be visible before
lock tail is updated. This can lead to lock corruption when, for
example, a concurrent locker races to set the next field.
Fixes: c55a6ffa62 ("locking/osq: Relax atomic semantics"):
Reported-by: David Daney <ddaney@caviumnetworks.com>
Reported-by: Andrew Pinski <andrew.pinski@caviumnetworks.com>
Tested-by: Andrew Pinski <andrew.pinski@caviumnetworks.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1449856001-21177-1-git-send-email-will.deacon@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a interrupt chip utilizes chip->buslock then free_irq() can
deadlock in the following way:
CPU0 CPU1
interrupt(X) (Shared or spurious)
free_irq(X) interrupt_thread(X)
chip_bus_lock(X)
irq_finalize_oneshot(X)
chip_bus_lock(X)
synchronize_irq(X)
synchronize_irq() waits for the interrupt thread to complete,
i.e. forever.
Solution is simple: Drop chip_bus_lock() before calling
synchronize_irq() as we do with the irq_desc lock. There is nothing to
be protected after the point where irq_desc lock has been released.
This adds chip_bus_lock/unlock() to the remove_irq() code path, but
that's actually correct in the case where remove_irq() is called on
such an interrupt. The current users of remove_irq() are not affected
as none of those interrupts is on a chip which requires buslock.
Reported-by: Fredrik Markström <fredrik.markstrom@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Jan Stancek reported that I wrecked things for him by fixing things for
Vladimir :/
His report was due to an UNINTERRUPTIBLE wait getting -EINTR, which
should not be possible, however my previous patch made this possible by
unconditionally checking signal_pending().
We cannot use current->state as was done previously, because the
instruction after the store to that variable it can be changed. We must
instead pass the initial state along and use that.
Fixes: 68985633bc ("sched/wait: Fix signal handling in bit wait helpers")
Reported-by: Jan Stancek <jstancek@redhat.com>
Reported-by: Chris Mason <clm@fb.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Chris Mason <clm@fb.com>
Reviewed-by: Paul Turner <pjt@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: tglx@linutronix.de
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: hpa@zytor.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the full stop_machine() routine is only enabled on SMP if
module unloading is enabled, or if the CPUs are hotpluggable. This
leads to configurations where stop_machine() is broken as it will then
only run the callback on the local CPU with irqs disabled, and not stop
the other CPUs or run the callback on them.
For example, this breaks MTRR setup on x86 in certain configs since
ea8596bb2d ("kprobes/x86: Remove unused text_poke_smp() and
text_poke_smp_batch() functions") as the MTRR is only established on the
boot CPU.
This patch removes the Kconfig option for STOP_MACHINE and uses the SMP
and HOTPLUG_CPU config options to compile the correct stop_machine() for
the architecture, removing the false dependency on MODULE_UNLOAD in the
process.
Link: https://lkml.org/lkml/2014/10/8/124
References: https://bugs.freedesktop.org/show_bug.cgi?id=84794
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Pranith Kumar <bobby.prani@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Iulia Manda <iulia.manda21@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Chuck Ebbert <cebbert.lkml@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cgroup fixes from Tejun Heo:
"More change than I'd have liked at this stage. The pids controller
and the changes made to cgroup core to support it introduced and
revealed several important issues.
- Assigning membership to a newly created task and migrating it can
race leading to incorrect accounting. Oleg fixed it by widening
threadgroup synchronization. It looks like we'll be able to merge
it with a different percpu rwsem which is used in fork path making
things simpler and cheaper.
- The recent change to extend cgroup membership to zombies (so that
pid accounting can extend till the pid is actually released) missed
pinning the underlying data structures leading to use-after-free.
Fixed.
- v2 hierarchy was calling subsystem callbacks with the wrong target
cgroup_subsys_state based on the incorrect assumption that they
share the same target. pids is the first controller affected by
this. Subsys callbacks updated so that they can deal with
multi-target migrations"
* 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup_pids: don't account for the root cgroup
cgroup: fix handling of multi-destination migration from subtree_control enabling
cgroup_freezer: simplify propagation of CGROUP_FROZEN clearing in freezer_attach()
cgroup: pids: kill pids_fork(), simplify pids_can_fork() and pids_cancel_fork()
cgroup: pids: fix race between cgroup_post_fork() and cgroup_migrate()
cgroup: make css_set pin its css's to avoid use-afer-free
cgroup: fix cftype->file_offset handling
Pull perf fixes from Ingo Molnar:
"This tree includes four core perf fixes for misc bugs, three fixes to
x86 PMU drivers, and two updates to old email addresses"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Do not send exit event twice
perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macro
perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on Haswell
perf: Fix PERF_EVENT_IOC_PERIOD deadlock
treewide: Remove old email address
perf/x86: Fix LBR call stack save/restore
perf: Update email address in MAINTAINERS
perf/core: Robustify the perf_cgroup_from_task() RCU checks
perf/core: Fix RCU problem with cgroup context switching code
The following commit which went into mainline through networking tree
3b13758f51 ("cgroups: Allow dynamically changing net_classid")
conflicts in net/core/netclassid_cgroup.c with the following pending
fix in cgroup/for-4.4-fixes.
1f7dd3e5a6 ("cgroup: fix handling of multi-destination migration from subtree_control enabling")
The former separates out update_classid() from cgrp_attach() and
updates it to walk all fds of all tasks in the target css so that it
can be used from both migration and config change paths. The latter
drops @css from cgrp_attach().
Resolve the conflict by making cgrp_attach() call update_classid()
with the css from the first task. We can revive @tset walking in
cgrp_attach() but given that net_cls is v1 only where there always is
only one target css during migration, this is fine.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Nina Schiff <ninasc@fb.com>
Pull scheduler fixes from Thomas Gleixner:
"This updates contains the following changes:
- Fix a signal handling regression in the bit wait functions.
- Avoid false positive warnings in the wakeup path.
- Initialize the scheduler root domain properly.
- Handle gtime calculations in proc/$PID/stat proper.
- Add more documentation for the barriers in try_to_wake_up().
- Fix a subtle race in try_to_wake_up() which might cause a task to
be scheduled on two cpus
- Compile static helper function only when it is used"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Fix an SMP ordering race in try_to_wake_up() vs. schedule()
sched/core: Better document the try_to_wake_up() barriers
sched/cputime: Fix invalid gtime in proc
sched/core: Clear the root_domain cpumasks in init_rootdomain()
sched/core: Remove false-positive warning from wake_up_process()
sched/wait: Fix signal handling in bit wait helpers
sched/rt: Hide the push_irq_work_func() declaration
In case we monitor events system wide, we get EXIT event
(when configured) twice for each task that exited.
Note doubled lines with same pid/tid in following example:
$ sudo ./perf record -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.480 MB perf.data (2518 samples) ]
$ sudo ./perf report -D | grep EXIT
0 60290687567581 0x59910 [0x38]: PERF_RECORD_EXIT(1250:1250):(1250:1250)
0 60290687568354 0x59948 [0x38]: PERF_RECORD_EXIT(1250:1250):(1250:1250)
0 60290687988744 0x59ad8 [0x38]: PERF_RECORD_EXIT(1250:1250):(1250:1250)
0 60290687989198 0x59b10 [0x38]: PERF_RECORD_EXIT(1250:1250):(1250:1250)
1 60290692567895 0x62af0 [0x38]: PERF_RECORD_EXIT(1253:1253):(1253:1253)
1 60290692568322 0x62b28 [0x38]: PERF_RECORD_EXIT(1253:1253):(1253:1253)
2 60290692739276 0x69a18 [0x38]: PERF_RECORD_EXIT(1252:1252):(1252:1252)
2 60290692739910 0x69a50 [0x38]: PERF_RECORD_EXIT(1252:1252):(1252:1252)
The reason is that the cpu contexts are processes each time
we call perf_event_task. I'm changing the perf_event_aux logic
to serve task_ctx and cpu contexts separately, which ensure we
don't get EXIT event generated twice on same cpu context.
This does not affect other auxiliary events, as they don't
use task_ctx at all.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1446649205-5822-1-git-send-email-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Oleg noticed that its possible to falsely observe p->on_cpu == 0 such
that we'll prematurely continue with the wakeup and effectively run p on
two CPUs at the same time.
Even though the overlap is very limited; the task is in the middle of
being scheduled out; it could still result in corruption of the
scheduler data structures.
CPU0 CPU1
set_current_state(...)
<preempt_schedule>
context_switch(X, Y)
prepare_lock_switch(Y)
Y->on_cpu = 1;
finish_lock_switch(X)
store_release(X->on_cpu, 0);
try_to_wake_up(X)
LOCK(p->pi_lock);
t = X->on_cpu; // 0
context_switch(Y, X)
prepare_lock_switch(X)
X->on_cpu = 1;
finish_lock_switch(Y)
store_release(Y->on_cpu, 0);
</preempt_schedule>
schedule();
deactivate_task(X);
X->on_rq = 0;
if (X->on_rq) // false
if (t) while (X->on_cpu)
cpu_relax();
context_switch(X, ..)
finish_lock_switch(X)
store_release(X->on_cpu, 0);
Avoid the load of X->on_cpu being hoisted over the X->on_rq load.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
