* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
BKL: That's all, folks
fs/locks.c: Remove stale FIXME left over from BKL conversion
ipx: remove the BKL
appletalk: remove the BKL
x25: remove the BKL
ufs: remove the BKL
hpfs: remove the BKL
drivers: remove extraneous includes of smp_lock.h
tracing: don't trace the BKL
adfs: remove the big kernel lock
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (116 commits)
x86: Enable forced interrupt threading support
x86: Mark low level interrupts IRQF_NO_THREAD
x86: Use generic show_interrupts
x86: ioapic: Avoid redundant lookup of irq_cfg
x86: ioapic: Use new move_irq functions
x86: Use the proper accessors in fixup_irqs()
x86: ioapic: Use irq_data->state
x86: ioapic: Simplify irq chip and handler setup
x86: Cleanup the genirq name space
genirq: Add chip flag to force mask on suspend
genirq: Add desc->irq_data accessor
genirq: Add comments to Kconfig switches
genirq: Fixup fasteoi handler for oneshot mode
genirq: Provide forced interrupt threading
sched: Switch wait_task_inactive to schedule_hrtimeout()
genirq: Add IRQF_NO_THREAD
genirq: Allow shared oneshot interrupts
genirq: Prepare the handling of shared oneshot interrupts
genirq: Make warning in handle_percpu_event useful
x86: ioapic: Move trigger defines to io_apic.h
...
Fix up trivial(?) conflicts in arch/x86/pci/xen.c due to genirq name
space changes clashing with the Xen cleanups. The set_irq_msi() had
moved to xen_bind_pirq_msi_to_irq().
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (26 commits)
sched: Resched proper CPU on yield_to()
sched: Allow users with sufficient RLIMIT_NICE to change from SCHED_IDLE policy
sched: Allow SCHED_BATCH to preempt SCHED_IDLE tasks
sched: Clean up the IRQ_TIME_ACCOUNTING code
sched: Add #ifdef around irq time accounting functions
sched, autogroup: Stop claiming ownership of the root task group
sched, autogroup: Stop going ahead if autogroup is disabled
sched, autogroup, sysctl: Use proc_dointvec_minmax() instead
sched: Fix the group_imb logic
sched: Clean up some f_b_g() comments
sched: Clean up remnants of sd_idle
sched: Wholesale removal of sd_idle logic
sched: Add yield_to(task, preempt) functionality
sched: Use a buddy to implement yield_task_fair()
sched: Limit the scope of clear_buddies
sched: Check the right ->nr_running in yield_task_fair()
sched: Avoid expensive initial update_cfs_load(), on UP too
sched: Fix switch_from_fair()
sched: Simplify the idle scheduling class
softirqs: Account ksoftirqd time as cpustat softirq
...
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (184 commits)
perf probe: Clean up probe_point_lazy_walker() return value
tracing: Fix irqoff selftest expanding max buffer
tracing: Align 4 byte ints together in struct tracer
tracing: Export trace_set_clr_event()
tracing: Explain about unstable clock on resume with ring buffer warning
ftrace/graph: Trace function entry before updating index
ftrace: Add .ref.text as one of the safe areas to trace
tracing: Adjust conditional expression latency formatting.
tracing: Fix event alignment: skb:kfree_skb
tracing: Fix event alignment: mce:mce_record
tracing: Fix event alignment: kvm:kvm_hv_hypercall
tracing: Fix event alignment: module:module_request
tracing: Fix event alignment: ftrace:context_switch and ftrace:wakeup
tracing: Remove lock_depth from event entry
perf header: Stop using 'self'
perf session: Use evlist/evsel for managing perf.data attributes
perf top: Don't let events to eat up whole header line
perf top: Fix events overflow in top command
ring-buffer: Remove unused #include <linux/trace_irq.h>
tracing: Add an 'overwrite' trace_option.
...
Although they run as rpciod background tasks, under normal operation
(i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_proc_unlck()
and nfs4_do_close() want to be fully synchronous. This means that when we
exit, we want all references to the rpc_task to be gone, and we want
any dentry references etc. held by that task to be released.
For this reason these functions call __rpc_wait_for_completion_task(),
followed by rpc_put_task() in the expectation that the latter will be
releasing the last reference to the rpc_task, and thus ensuring that the
callback_ops->rpc_release() has been called synchronously.
This patch fixes a race which exists due to the fact that
rpciod calls rpc_complete_task() (in order to wake up the callers of
__rpc_wait_for_completion_task()) and then subsequently calls
rpc_put_task() without ensuring that these two steps are done atomically.
In order to avoid adding new spin locks, the patch uses the existing
waitqueue spin lock to order the rpc_task reference count releases between
the waiting process and rpciod.
The common case where nobody is waiting for completion is optimised for by
checking if the RPC_TASK_ASYNC flag is cleared and/or if the rpc_task
reference count is 1: in those cases we drop trying to grab the spin lock,
and immediately free up the rpc_task.
Those few processes that need to put the rpc_task from inside an
asynchronous context and that do not care about ordering are given a new
helper: rpc_put_task_async().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This removes the implementation of the big kernel lock,
at last. A lot of people have worked on this in the
past, I so the credit for this patch should be with
everyone who participated in the hunt.
The names on the Cc list are the people that were the
most active in this, according to the recorded git
history, in alphabetical order.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: Alessio Igor Bogani <abogani@texware.it>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Jan Blunck <jblunck@infradead.org>
Cc: John Kacur <jkacur@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Paul Menage <menage@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
yield_to_task_fair() has code to resched the CPU of yielding task when the
intention is to resched the CPU of the task that is being yielded to.
Change here fixes the problem and also makes the resched conditional on
rq != p_rq.
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1299025701-22168-1-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The current scheduler implementation returns -EPERM when trying to
change from SCHED_IDLE to SCHED_OTHER or SCHED_BATCH. Since SCHED_IDLE
is considered to be a nice 20 on steroids, changing to another policy
should be allowed provided the RLIMIT_NICE is accounted for.
This patch allows the following test-case to pass with RLIMIT_NICE=40,
but still fail with RLIMIT_NICE=10 when the calling process is run
from a typical shell (nice 0, or 20 in rlimit terms).
int main()
{
int ret;
struct sched_param sp;
sp.sched_priority = 0;
/* switch to SCHED_IDLE */
ret = sched_setscheduler(0, SCHED_IDLE, &sp);
printf("setscheduler IDLE: %d\n", ret);
if (ret) return ret;
/* switch back to SCHED_OTHER */
ret = sched_setscheduler(0, SCHED_OTHER, &sp);
printf("setscheduler OTHER: %d\n", ret);
return ret;
}
$ ulimit -e
40
$ ./test
setscheduler IDLE: 0
setscheduler OTHER: 0
$ ulimit -e 10
$ ulimit -e
10
$ ./test
setscheduler IDLE: 0
setscheduler OTHER: -1
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Purdie <richard.purdie@linuxfoundation.org>
LKML-Reference: <4D657BEE.4040608@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix this warning:
lkml.org/lkml/2011/1/30/124
kernel/sched.c:3719: warning: 'irqtime_account_idle_ticks' defined but not used
kernel/sched.c:3720: warning: 'irqtime_account_process_tick' defined but not used
In a cleaner way than:
7e9498705e81: sched: Add #ifdef around irq time accounting functions
This patch will not have any functional impact.
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Cc: heiko.carstens@de.ibm.com
Cc: a.p.zijlstra@chello.nl
LKML-Reference: <1298675596-10992-1-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When we force thread hard and soft interrupts the startup of ksoftirqd
would hang in kthread_bind() when wait_task_inactive() calls
schedule_timeout_uninterruptible() because there is no softirq yet
which will wake us up.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110223234956.677109139@linutronix.de>
Get rid of this:
kernel/sched.c:3731:13: warning: 'irqtime_account_idle_ticks' defined but not used
kernel/sched.c:3732:13: warning: 'irqtime_account_process_tick' defined but not used
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Venkatesh Pallipadi <venki@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110225133228.GD7469@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make the ::exit method act like ::attach, it is after all very nearly
the same thing.
The bug had no effect on correctness - fixing it is an optimization for
the scheduler. Also, later perf-cgroups patches rely on it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Menage <menage@google.com>
LKML-Reference: <1297160655.13327.92.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the fuction graph tracer starts, it needs to make a special
stack for each task to save the real return values of the tasks.
All running tasks have this stack created, as well as any new
tasks.
On CPU hot plug, the new idle task will allocate a stack as well
when init_idle() is called. The problem is that cpu hotplug does
not create a new idle_task. Instead it uses the idle task that
existed when the cpu went down.
ftrace_graph_init_task() will add a new ret_stack to the task
that is given to it. Because a clone will make the task
have a stack of its parent it does not check if the task's
ret_stack is already NULL or not. When the CPU hotplug code
starts a CPU up again, it will allocate a new stack even
though one already existed for it.
The solution is to treat the idle_task specially. In fact, the
function_graph code already does, just not at init_idle().
Instead of using the ftrace_graph_init_task() for the idle task,
which that function expects the task to be a clone, have a
separate ftrace_graph_init_idle_task(). Also, we will create a
per_cpu ret_stack that is used by the idle task. When we call
ftrace_graph_init_idle_task() it will check if the idle task's
ret_stack is NULL, if it is, then it will assign it the per_cpu
ret_stack.
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently only implemented for fair class tasks.
Add a yield_to_task method() to the fair scheduling class. allowing the
caller of yield_to() to accelerate another thread in it's thread group,
task group.
Implemented via a scheduler hint, using cfs_rq->next to encourage the
target being selected. We can rely on pick_next_entity to keep things
fair, so noone can accelerate a thread that has already used its fair
share of CPU time.
This also means callers should only call yield_to when they really
mean it. Calling it too often can result in the scheduler just
ignoring the hint.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use the buddy mechanism to implement yield_task_fair. This
allows us to skip onto the next highest priority se at every
level in the CFS tree, unless doing so would introduce gross
unfairness in CPU time distribution.
We order the buddy selection in pick_next_entity to check
yield first, then last, then next. We need next to be able
to override yield, because it is possible for the "next" and
"yield" task to be different processen in the same sub-tree
of the CFS tree. When they are, we need to go into that
sub-tree regardless of the "yield" hint, and pick the correct
entity once we get to the right level.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201095103.3a79e92a@annuminas.surriel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Oleg reported that on architectures with
__ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from
task_oncpu_function_call() can land before perf_event_task_sched_in()
and cause interesting situations for eg. perf_install_in_context().
This patch reworks the task_oncpu_function_call() interface to give a
more usable primitive as well as rework all its users to hopefully be
more obvious as well as remove the races.
While looking at the code I also found a number of races against
perf_event_task_sched_out() which can flip contexts between tasks so
plug those too.
Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix the build on UP.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>
LKML-Reference: <20110122044852.102126037@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When a task is taken out of the fair class we must ensure the vruntime
is properly normalized because when we put it back in it will assume
to be normalized.
The case that goes wrong is when changing away from the fair class
while sleeping. Sleeping tasks have non-normalized vruntime in order
to make sleeper-fairness work. So treat the switch away from fair as a
wakeup and preserve the relative vruntime.
Also update sysrq-n to call the ->switch_{to,from} methods.
Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
softirq time in ksoftirqd context is not accounted in ns granularity
per cpu softirq stats, as we want that to be a part of ksoftirqd
exec_runtime.
Accounting them as softirq on /proc/stat separately.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-6-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU.
This info is already used in scheduler to do proper task chargeback
(earlier patches). This patch retro-fits this ns granularity
hardirq and softirq information to /proc/stat irq and softirq fields.
The update is still done on timer tick, where we look at accumulated
ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest
accordingly.
No new interface added.
Earlier versions looked at adding this as new fields in some /proc
files. This one seems to be the best in terms of impact to existing
apps, even though it has somewhat more kernel code than earlier versions.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Refactor account_system_time, to separate out the logic of
identifying the update needed and code that does actual update.
This is used by following patch for IRQ_TIME_ACCOUNTING,
which has different identification logic and same update logic.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cleanup patch, freeing up PF_KSOFTIRQD and use per_cpu ksoftirqd pointer
instead, as suggested by Eric Dumazet.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-2-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since cfs->{load_stamp,load_last} are zero-initalized the initial load update
will consider the delta to be 'since the beginning of time'.
This results in a lot of pointless divisions to bring this large period to be
within the sysctl_sched_shares_window.
Fix this by initializing load_stamp to be 1 at cfs_rq initialization, this
allows for an initial load_stamp > load_last which then lets standard idle
truncation proceed.
We avoid spinning (and slightly improve consistency) by fixing delta to be
[period - 1] in this path resulting in a slightly more predictable shares ramp.
(Previously the amount of idle time preserved by the overflow would range between
[period/2,period-1].)
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044852.102126037@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Re-visiting this: Since update_cfs_shares will now only ever re-weight an
entity that is a relative parent of the current entity in enqueue_entity; we
can safely issue the account_entity_enqueue relative to that cfs_rq and avoid
the requirement for special handling of the enqueue case in update_cfs_shares.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.915214637@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched, cgroup: Use exit hook to avoid use-after-free crash
sched: Fix signed unsigned comparison in check_preempt_tick()
sched: Replace rq->bkl_count with rq->rq_sched_info.bkl_count
sched, autogroup: Fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure
sched: Display autogroup names in /proc/sched_debug
sched: Reinstate group names in /proc/sched_debug
sched: Update effective_load() to use global share weights
By not notifying the controller of the on-exit move back to
init_css_set, we fail to move the task out of the previous
cgroup's cfs_rq. This leads to an opportunity for a
cgroup-destroy to come in and free the cgroup (there are no
active tasks left in it after all) to which the not-quite dead
task is still enqueued.
Reported-by: Miklos Vajna <vmiklos@frugalware.org>
Fixed-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1293206353.29444.205.camel@laptop>
Now rq->rq_sched_info.bkl_count is not used for rq, scroll
rq->bkl_count into it. Thus we can save some space for rq.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294991859-13246-1-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If CONFIG_RT_GROUP_SCHED is set, __sched_setscheduler() fails due to autogroup
not allocating rt_runtime. Free unused/unusable rt_se and rt_rq, redirect RT
tasks to the root task group, and tell __sched_setscheduler() that it's ok.
Reported-and-tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294890890.8089.39.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
One of the operands, buf, is incorrect, since it is stripped and the
correct address for subsequent string comparing could change if
leading white spaces, if any, are removed from buf.
It is fixed by replacing buf with cmp.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <AANLkTinOPuYsVovrZpbuCCmG5deEyc8WgA_A1RJx_YK7@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Seems I lost a change somewhere, leaking memory.
sched: fix struct autogroup memory leak
Add missing change to actually use autogroup_free().
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294222285.8369.2.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
root_task_group is the leftover of USER_SCHED, now it's always
same to init_task_group.
But as Mike suggested, root_task_group is maybe the suitable name
to keep for a tree.
So in this patch:
init_task_group --> root_task_group
init_task_group_load --> root_task_group_load
INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD
Suggested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110107071736.GA32635@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
sched: Change wait_for_completion_*_timeout() to return a signed long
sched, autogroup: Fix reference leak
sched, autogroup: Fix potential access to freed memory
sched: Remove redundant CONFIG_CGROUP_SCHED ifdef
sched: Fix interactivity bug by charging unaccounted run-time on entity re-weight
sched: Move periodic share updates to entity_tick()
printk: Use this_cpu_{read|write} api on printk_pending
sched: Make pushable_tasks CONFIG_SMP dependant
sched: Add 'autogroup' scheduling feature: automated per session task groups
sched: Fix unregister_fair_sched_group()
sched: Remove unused argument dest_cpu to migrate_task()
mutexes, sched: Introduce arch_mutex_cpu_relax()
sched: Add some clock info to sched_debug
cpu: Remove incorrect BUG_ON
cpu: Remove unused variable
sched: Fix UP build breakage
sched: Make task dump print all 15 chars of proc comm
sched: Update tg->shares after cpu.shares write
sched: Allow update_cfs_load() to update global load
sched: Implement demand based update_cfs_load()
...
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (146 commits)
tools, perf: Documentation for the power events API
perf: Add calls to suspend trace point
perf script: Make some lists static
perf script: Use the default lost event handler
perf session: Warn about errors when processing pipe events too
perf tools: Fix perf_event.h header usage
perf test: Clarify some error reports in the open syscall test
x86, NMI: Add touch_nmi_watchdog to io_check_error delay
x86: Avoid calling arch_trigger_all_cpu_backtrace() at the same time
x86: Only call smp_processor_id in non-preempt cases
perf timechart: Adjust perf timechart to the new power events
perf: Clean up power events by introducing new, more generic ones
perf: Do not export power_frequency, but power_start event
perf test: Add test for counting open syscalls
perf evsel: Auto allocate resources needed for some methods
perf evsel: Use {cpu,thread}_map to shorten list of parameters
perf tools: Refactor all_tids to hold nr and the map
perf tools: Refactor cpumap to hold nr and the map
perf evsel: Introduce per cpu and per thread open helpers
perf evsel: Steal the counter reading routines from stat
...
wait_for_completion_*_timeout() can return:
0: if the wait timed out
-ve: if the wait was interrupted
+ve: if the completion was completed.
As they currently return an 'unsigned long', the last two cases
are not easily distinguished which can easily result in buggy
code, as is the case for the recently added
wait_for_completion_interruptible_timeout() call in
net/sunrpc/cache.c
So change them both to return 'long'. As MAX_SCHEDULE_TIMEOUT
is LONG_MAX, a large +ve return value should never overflow.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110105125016.64ccab0e@notabene.brown>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
MAINTAINERS
arch/arm/mach-omap2/pm24xx.c
drivers/scsi/bfa/bfa_fcpim.c
Needed to update to apply fixes for which the old branch was too
outdated.
Linus reported that the new warning introduced by commit f26f9aff6a
"Sched: fix skip_clock_update optimization" triggers. The need_resched
flag can be set by other CPUs asynchronously so this debug check is
bogus - remove it.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <AANLkTinJ8hAG1TpyC+CSYPR47p48+1=E7fiC45hMXT_1@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently we call perf_event_init() from sched_init(). In order to
make it more obvious move it to the cannnonical location.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.093629821@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since the irqtime accounting is using non-atomic u64 and can be read
from remote cpus (writes are strictly cpu local, reads are not) we
have to deal with observing partial updates.
When we do observe partial updates the clock movement (in particular,
->clock_task movement) will go funny (in either direction), a
subsequent clock update (observing the full update) will make it go
funny in the oposite direction.
Since we rely on these clocks to be strictly monotonic we cannot
suffer backwards motion. One possible solution would be to simply
ignore all backwards deltas, but that will lead to accounting
artefacts, most notable: clock_task + irq_time != clock, this
inaccuracy would end up in user visible stats.
Therefore serialize the reads using a seqcount.
Reviewed-by: Venkatesh Pallipadi <venki@google.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292242434.6803.200.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some ARM systems have a short sched_clock() [ which needs to be fixed
too ], but this exposed a bug in the irq_time code as well, it doesn't
deal with wraps at all.
Fix the irq_time code to deal with u64 wraps by re-writing the code to
only use delta increments, which avoids the whole issue.
Reviewed-by: Venkatesh Pallipadi <venki@google.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292242433.6803.199.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As noted by Peter Zijlstra at https://lkml.org/lkml/2010/11/10/391
(while reviewing other stuff, though), tracking pushable tasks
only makes sense on SMP systems.
Signed-off-by: Dario Faggioli <raistlin@linux.it>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1291143093.2697.298.camel@Palantir>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
idle_balance() drops/retakes rq->lock, leaving the previous task
vulnerable to set_tsk_need_resched(). Clear it after we return
from balancing instead, and in setup_thread_stack() as well, so
no successfully descheduled or never scheduled task has it set.
Need resched confused the skip_clock_update logic, which assumes
that the next call to update_rq_clock() will come nearly immediately
after being set. Make the optimization robust against the waking
a sleeper before it sucessfully deschedules case by checking that
the current task has not been dequeued before setting the flag,
since it is that useless clock update we're trying to save, and
clear unconditionally in schedule() proper instead of conditionally
in put_prev_task().
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reported-by: Bjoern B. Brandenburg <bbb.lst@gmail.com>
Tested-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
LKML-Reference: <1291802742.1417.9.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There's a long-running regression that proved difficult to fix and
which is hitting certain people and is rather annoying in its effects.
Damien reported that after 74f5187ac8 (sched: Cure load average vs
NO_HZ woes) his load average is unnaturally high, he also noted that
even with that patch reverted the load avgerage numbers are not
correct.
The problem is that the previous patch only solved half the NO_HZ
problem, it addressed the part of going into NO_HZ mode, not of
comming out of NO_HZ mode. This patch implements that missing half.
When comming out of NO_HZ mode there are two important things to take
care of:
- Folding the pending idle delta into the global active count.
- Correctly aging the averages for the idle-duration.
So with this patch the NO_HZ interaction should be complete and
behaviour between CONFIG_NO_HZ=[yn] should be equivalent.
Furthermore, this patch slightly changes the load average computation
by adding a rounding term to the fixed point multiplication.
Reported-by: Damien Wyart <damien.wyart@free.fr>
Reported-by: Tim McGrath <tmhikaru@gmail.com>
Tested-by: Damien Wyart <damien.wyart@free.fr>
Tested-by: Orion Poplawski <orion@cora.nwra.com>
Tested-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
Cc: Chase Douglas <chase.douglas@canonical.com>
LKML-Reference: <1291129145.32004.874.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
A recurring complaint from CFS users is that parallel kbuild has
a negative impact on desktop interactivity. This patch
implements an idea from Linus, to automatically create task
groups. Currently, only per session autogroups are implemented,
but the patch leaves the way open for enhancement.
Implementation: each task's signal struct contains an inherited
pointer to a refcounted autogroup struct containing a task group
pointer, the default for all tasks pointing to the
init_task_group. When a task calls setsid(), a new task group
is created, the process is moved into the new task group, and a
reference to the preveious task group is dropped. Child
processes inherit this task group thereafter, and increase it's
refcount. When the last thread of a process exits, the
process's reference is dropped, such that when the last process
referencing an autogroup exits, the autogroup is destroyed.
At runqueue selection time, IFF a task has no cgroup assignment,
its current autogroup is used.
Autogroup bandwidth is controllable via setting it's nice level
through the proc filesystem:
cat /proc/<pid>/autogroup
Displays the task's group and the group's nice level.
echo <nice level> > /proc/<pid>/autogroup
Sets the task group's shares to the weight of nice <level> task.
Setting nice level is rate limited for !admin users due to the
abuse risk of task group locking.
The feature is enabled from boot by default if
CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via
the boot option noautogroup, and can also be turned on/off on
the fly via:
echo [01] > /proc/sys/kernel/sched_autogroup_enabled
... which will automatically move tasks to/from the root task group.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Paul Turner <pjt@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
[ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Linus Torvalds