linux-kernel - [GIT PULL] vtime: Delay cputime accounting to tick / context switch

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Date:   Tue, 10 Jan 2017 16:19:46 +0100
From:   Frederic Weisbecker <fweisbec@...il.com>
To:     Ingo Molnar <mingo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Frederic Weisbecker <fweisbec@...il.com>,
        Tony Luck <tony.luck@...el.com>,
        Wanpeng Li <wanpeng.li@...mail.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Heiko Carstens <heiko.carstens@...ibm.com>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Christian Borntraeger <borntraeger@...ibm.com>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Rik van Riel <riel@...hat.com>,
        Martin Schwidefsky <schwidefsky@...ibm.com>,
        Stanislaw Gruszka <sgruszka@...hat.com>
Subject: [GIT PULL] vtime: Delay cputime accounting to tick / context switch

Ingo, Thomas,

Please pull the vtime/accumulate-for-tip branch that can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
	vtime/accumulate-for-tip

HEAD: 0fe66425659da25269280c106f39b333a0cfb9a9

---
The cputime accounting functions (account_system_time(),
account_user_time(), ...) happen to be costly especially under several
common configs. And with CONFIG_VIRT_CPU_ACCOUNTING_NATIVE those functions
are called on many fast paths such as context boundaries like
user <-> kernel, kernel <-> guest, kernel <-> idle, kernel <-> (soft)IRQ,
context switches, etc...

This set reduces this overhead by accumulating the cputime on context
boundaries and eventually delay the accounting of that accumulated time
on ticks and context switches only.
---

Thanks,
	Frederic
---

Frederic Weisbecker (9):
      powerpc32: Fix stale scaled stime on context switch
      ia64: Fix wrong start cputime assignment on task switch
      cputime: Allow accounting system time using cpustat index
      cputime: Export account_guest_time
      powerpc: Prepare accounting structure for cputime flush on tick
      powerpc: Migrate stolen_time field to accounting structure
      powerpc/vtime: Accumulate cputime and account only on tick/task switch
      ia64: Accumulate cputime and account only on tick/task switch
      vtime: Rename vtime_account_user() to vtime_flush()

Martin Schwidefsky (1):
      s390/cputime: Delayed accounting of system time


 arch/ia64/include/asm/thread_info.h   |   6 ++
 arch/ia64/kernel/time.c               |  66 +++++++++++-----
 arch/powerpc/include/asm/accounting.h |  14 +++-
 arch/powerpc/include/asm/paca.h       |   1 -
 arch/powerpc/kernel/asm-offsets.c     |   8 +-
 arch/powerpc/kernel/time.c            | 138 +++++++++++++++++++++-------------
 arch/powerpc/xmon/xmon.c              |   8 +-
 arch/s390/include/asm/lowcore.h       |  65 ++++++++--------
 arch/s390/include/asm/processor.h     |   3 +
 arch/s390/kernel/vtime.c              | 138 ++++++++++++++++++++++------------
 include/linux/kernel_stat.h           |   5 +-
 include/linux/vtime.h                 |   7 +-
 kernel/sched/cputime.c                |  16 ++--
 13 files changed, 302 insertions(+), 173 deletions(-)