linux.git/kernel/sched/cpuacct.c, branch v4.13

sched/cputime: Convert kcpustat to nsecs

2017-02-01T08:13:47+00:00

Kernel CPU stats are stored in cputime_t which is an architecture
defined type, and hence a bit opaque and requiring accessors and mutators
for any operation.

Converting them to nsecs simplifies the code and is one step toward
the removal of cputime_t in the core code.

Signed-off-by: Frederic Weisbecker 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Stanislaw Gruszka 
Cc: Wanpeng Li 
Link: http://lkml.kernel.org/r/1485832191-26889-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar

sched/cpuacct: Avoid %lld seq_printf warning

2016-11-16T09:29:03+00:00

For s390 kernel builds I keep getting this warning:

 kernel/sched/cpuacct.c: In function 'cpuacct_stats_show':
 kernel/sched/cpuacct.c:298:25: warning: format '%lld' expects argument of type 'long long int', but argument 4 has type 'clock_t {aka long int}' [-Wformat=]
   seq_printf(sf, "%s %lld\n",

Silence the warning by adding an explicit cast.

Signed-off-by: Martin Schwidefsky 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20161111142749.6545-1-schwidefsky@de.ibm.com
Signed-off-by: Ingo Molnar

sched/cpuacct: Introduce cpuacct.usage_all to show all CPU stats together

2016-07-09T11:56:15+00:00

In current code, we can get cpuacct data from several files,
but each file has various limitations.

For example:

 - We can get CPU usage in user and kernel mode via cpuacct.stat,
   but we can't get detailed data about each CPU.

 - We can get each CPU's kernel mode usage in cpuacct.usage_percpu_sys,
   but we can't get user mode usage data at the same time.

This patch introduces cpuacct.usage_all, to show all detailed CPU
accounting data together:

 # cat cpuacct.usage_all
 cpu user system
 0 3809760299 5807968992
 1 3250329855 454612211
 ..

Signed-off-by: Zhao Lei 
Cc: KOSAKI Motohiro 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/7744460969edd7caaf0e903592ee52353ed9bdd6.1466415271.git.zhaolei@cn.fujitsu.com
Signed-off-by: Ingo Molnar

sched/cpuacct: Use loop to consolidate code in cpuacct_stats_show()

2016-07-09T11:56:15+00:00

In cpuacct_stats_show() we currently we have copies of similar code,
for each cpustat(system/user) variant.

Use a loop instead to consolidate the code. This will also work better
if we extend the CPUACCT_STAT_NSTATS type.

Signed-off-by: Zhao Lei 
Cc: KOSAKI Motohiro 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/b0597d4224655e9f333f1a6224ed9654c7d7d36a.1466415271.git.zhaolei@cn.fujitsu.com
Signed-off-by: Ingo Molnar

sched/cpuacct: Merge cpuacct_usage_index and cpuacct_stat_index enums

2016-07-09T11:56:15+00:00

These two types have similar function, no need to separate them.

Signed-off-by: Zhao Lei 
Cc: KOSAKI Motohiro 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/436748885270d64363c7dc67167507d486c2057a.1466415271.git.zhaolei@cn.fujitsu.com
Signed-off-by: Ingo Molnar

sched/cpuacct: Check for NULL when using task_pt_regs()

2016-04-13T11:22:37+00:00

task_pt_regs() can return NULL for kernel threads, so add a check.
This fixes an oops at boot on ppc64.

Reported-and-Tested-by: Srikar Dronamraju 
Tested-by: Zhao Lei 
Signed-off-by: Anton Blanchard 
Acked-by: Zhao Lei 
Cc: Linus Torvalds 
Cc: Michael Ellerman 
Cc: Peter Zijlstra 
Cc: Stephen Rothwell 
Cc: Thomas Gleixner 
Cc: efault@gmx.de
Cc: htejun@gmail.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: tj@kernel.org
Cc: yangds.fnst@cn.fujitsu.com
Link: http://lkml.kernel.org/r/20160406215950.04bc3f0b@kryten
Signed-off-by: Ingo Molnar

sched/cpuacct: Split usage accounting into user_usage and sys_usage

2016-03-31T08:48:54+00:00

Sometimes, cpuacct.usage is not detailed enough to see how much CPU
usage a group had. We want to know how much time it used in user mode
and how much in kernel mode.

This patch introduces more files to give this information:

 # ls /sys/fs/cgroup/cpuacct/cpuacct.usage*
 /sys/fs/cgroup/cpuacct/cpuacct.usage
 /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu
 /sys/fs/cgroup/cpuacct/cpuacct.usage_user
 /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu_user
 /sys/fs/cgroup/cpuacct/cpuacct.usage_sys
 /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu_sys

... while keeping the ABI with the existing counter.

Signed-off-by: Dongsheng Yang 
[ Ported to newer kernels. ]
Signed-off-by: Zhao Lei 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Tejun Heo 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/aa171da036b520b51c79549e9b3215d29473f19d.1458635566.git.zhaolei@cn.fujitsu.com
Signed-off-by: Ingo Molnar

sched/cpuacct: Show all possible CPUs in cpuacct output

2016-03-31T08:45:56+00:00

Current code show stats of online CPUs in cpuacct.statcpus,
show stats of present cpus in cpuacct.usage(_percpu), and using
present CPUs for setting cpuacct.usage.

It will cause inconsistent result when a CPU is online or offline
or hotpluged.

We should always use possible CPUs to avoid above problem.

Here are the contents of a cpuacct.usage_percpu sysfs file,
on a 4 CPU system with maxcpus=32:

Before the patch:
 # cat cpuacct.usage_percpu
 2456565 411435 1052897 832584

After the patch:
 # cat cpuacct.usage_percpu
 2456565 411435 1052897 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Suggested-by: Peter Zijlstra 
Signed-off-by: Zhao Lei 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/a11d56cef12d0b4807f8be3a46bf9798c3014d59.1458635566.git.zhaolei@cn.fujitsu.com
Signed-off-by: Ingo Molnar

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-03-24T16:42:50+00:00

Pull scheduler fixes from Ingo Molnar:
 "Misc fixes: a cgroup fix, a fair-scheduler migration accounting fix, a
  cputime fix and two cpuacct cleanups"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/cpuacct: Simplify the cpuacct code
  sched/cpuacct: Rename parameter in cpuusage_write() for readability
  sched/fair: Add comments to explain select_idle_sibling()
  sched/fair: Fix fairness issue on migration
  sched/cgroup: Fix/cleanup cgroup teardown/init
  sched/cputime: Fix steal time accounting vs. CPU hotplug

sched/cpuacct: Simplify the cpuacct code

2016-03-21T10:00:28+00:00

 - Use for() instead of while() loop in some functions
   to make the code simpler.

 - Use this_cpu_ptr() instead of per_cpu_ptr() to make the code
   cleaner and a bit faster.

Suggested-by: Peter Zijlstra 
Signed-off-by: Zhao Lei 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/d8a7ef9592f55224630cb26dea239f05b6398a4e.1458187654.git.zhaolei@cn.fujitsu.com
Signed-off-by: Ingo Molnar