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From: Venkatesh Pallipadi <venki@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Balbir Singh <balbir@linux.vnet.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linux-kernel@vger.kernel.org, Paul Turner <pjt@google.com>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Shaun Ruffell <sruffell@digium.com>,
	Venkatesh Pallipadi <venki@google.com>
Subject: [PATCH 0/5] Proper kernel irq time reporting -v2
Date: Tue, 21 Dec 2010 17:08:59 -0800	[thread overview]
Message-ID: <1292980144-28796-1-git-send-email-venki@google.com> (raw)

This is Part 2 of
"Proper kernel irq time accounting -v4"
http://lkml.indiana.edu/hypermail//linux/kernel/1010.0/01175.html

and applies over 2.6.37-rc7.

Part 1 solves the way irqs are accounted in scheduler and tasks. This
patchset solves how irq times are reported in /proc/stat and also not
to include irq time in task->stime, etc.

Example:
Running a cpu intensive loop and network intensive nc on a 4 CPU system
and looking at 'top' output.

With vanilla kernel:
Cpu0  :  0.0% us,  0.3% sy,  0.0% ni, 99.3% id,  0.0% wa,  0.0% hi,  0.3% si
Cpu1  : 100.0% us,  0.0% sy,  0.0% ni,  0.0% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu2  :  1.3% us, 27.2% sy,  0.0% ni,  0.0% id,  0.0% wa,  0.0% hi, 71.4% si
Cpu3  :  1.6% us,  1.3% sy,  0.0% ni, 96.7% id,  0.0% wa,  0.0% hi,  0.3% si

 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 7555 root      20   0  1760  528  436 R  100  0.0   0:15.79 nc
 7563 root      20   0  3632  268  204 R  100  0.0   0:13.13 loop

Notes:
* Both tasks show 100% CPU, even when one of them is stuck on a CPU thats
  processing 70% softirq.
* no hardirq time.


With "Part 1" patches:
Cpu0  :  0.0% us,  0.0% sy,  0.0% ni, 100.0% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu1  : 100.0% us,  0.0% sy,  0.0% ni,  0.0% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu2  :  2.0% us, 30.6% sy,  0.0% ni,  0.0% id,  0.0% wa,  0.0% hi, 67.4% si
Cpu3  :  0.7% us,  0.7% sy,  0.3% ni, 98.3% id,  0.0% wa,  0.0% hi,  0.0% si

 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 6289 root      20   0  3632  268  204 R  100  0.0   2:18.67 loop
 5737 root      20   0  1760  528  436 R   33  0.0   0:26.72 nc

Notes:
* Tasks show 100% CPU and 33% CPU that correspond to their non-irq exec time.
* no hardirq time.


With "Part 1 + Part 2" patches:
Cpu0  :  1.3% us,  1.0% sy,  0.3% ni, 97.0% id,  0.0% wa,  0.0% hi,  0.3% si
Cpu1  : 99.3% us,  0.0% sy,  0.0% ni,  0.0% id,  0.0% wa,  0.7% hi,  0.0% si
Cpu2  :  1.3% us, 31.5% sy,  0.0% ni,  0.0% id,  0.0% wa,  8.3% hi, 58.9% si
Cpu3  :  1.0% us,  2.0% sy,  0.3% ni, 95.0% id,  0.0% wa,  0.7% hi,  1.0% si

 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
20929 root      20   0  3632  268  204 R   99  0.0   3:48.25 loop
20796 root      20   0  1760  528  436 R   33  0.0   2:38.65 nc

Notes:
* Both task exec time and hard irq time reported correctly.
* hi and si time are based on fine granularity info and not on samples.
* getrusage would give proper utime/stime split not including irq times
  in that ratio.
* Other places that report user/sys time like, cgroup cpuacct.stat will
  now include only non-irq exectime.


Changes since v1:
( v1 - http://kerneltrap.com/mailarchive/linux-kernel/2010/10/25/4637170 )
* Rebase over other related code changes since v1

Signed-off-by: Venkatesh Pallipadi <venki@google.com>

             reply	other threads:[~2010-12-22  1:09 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-22  1:08 Venkatesh Pallipadi [this message]
2010-12-22  1:09 ` [PATCH 1/5] Free up pf flag PF_KSOFTIRQD -v2 Venkatesh Pallipadi
2010-12-22  9:17   ` Peter Zijlstra
2011-01-26 12:11   ` [tip:sched/core] softirqs: Free up pf flag PF_KSOFTIRQD tip-bot for Venkatesh Pallipadi
2010-12-22  1:09 ` [PATCH 2/5] Add nsecs_to_cputime64 interface for asm-generic -v2 Venkatesh Pallipadi
2010-12-22  8:30   ` Martin Schwidefsky
2010-12-22 14:23     ` Venkatesh Pallipadi
2010-12-22 15:25       ` Martin Schwidefsky
2011-01-26 12:12   ` [tip:sched/core] time: Add nsecs_to_cputime64 interface for asm-generic tip-bot for Venkatesh Pallipadi
2010-12-22  1:09 ` [PATCH 3/5] Refactor account_system_time separating id-update -v2 Venkatesh Pallipadi
2011-01-26 12:12   ` [tip:sched/core] sched: Refactor account_system_time separating id-update tip-bot for Venkatesh Pallipadi
2010-12-22  1:09 ` [PATCH 4/5] Export ns irqtimes through /proc/stat -v2 Venkatesh Pallipadi
2011-01-26 12:13   ` [tip:sched/core] sched: Export ns irqtimes through /proc/stat tip-bot for Venkatesh Pallipadi
2010-12-22  1:09 ` [PATCH 5/5] Account ksoftirqd time as cpustat softirq -v2 Venkatesh Pallipadi
2010-12-22  9:20   ` Peter Zijlstra
2010-12-22 13:59     ` Venkatesh Pallipadi
2010-12-22 14:05       ` Peter Zijlstra
2010-12-22 14:17         ` Venkatesh Pallipadi
2011-01-26 12:13   ` [tip:sched/core] softirqs: Account ksoftirqd time as cpustat softirq tip-bot for Venkatesh Pallipadi
2011-01-06 15:31 ` [PATCH 0/5] Proper kernel irq time reporting -v2 Shaun Ruffell

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