[PATCH 00/36] cputime: Convert core use of cputime_t to nsecs
From: Frederic Weisbecker
Date: Thu Nov 17 2016 - 13:08:56 EST
I'm sorry for the patchbomb, especially as I usually complain about
these myself but I don't see any way to split this patchset into
standalone pieces, none of which would make any sense... All I can do
is to isolate about 3 cleanup patches.
So currently, cputime_t serves the purpose, for s390 and
powerpc (on CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y), to avoid converting
arch clock counters to nanosecs or jiffies while accounting cputime.
But this comes at the cost of a lot of complexity and uglification
in the core code to deal with such an opaque type that relies on lots of
mutators and accessors in order to deal with a random granularity time
unit that also involve lots of workarounds and likely some performance
penalties.
So this patchset proposes to convert most of the cputime_t uses to nsecs.
In the end it's only used by s390 and powerpc. This all comes at the
expense of those two archs which then need to perform a cputime_to_nsec()
conversion everytime they update the cputime to the core. Now I expect
we can leverage this performance loss with flushing the cputime only on
ticks so that we accumulate time as cputime_t in between and make the
conversions more rare.
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
cputime/nsecs-v2
HEAD: cf109941db5da247569ee99a6effe00f62537082
Thanks,
Frederic
---
Frederic Weisbecker (36):
jiffies: Reuse TICK_NSEC instead of NSEC_PER_JIFFY
time: Introduce jiffies64_to_nsecs()
sched: Remove unused INIT_CPUTIME macro
cputime: Convert kcpustat to nsecs
macintosh/rack-meter: Remove cputime_t internal use
cputime: Convert guest time accounting to nsecs
cputime: Special API to return old-typed cputime
cputime: Convert task/group cputime to nsecs
alpha: Convert obsolete cputime_t to nsecs
x86: Convert obsolete cputime type to nsecs
isdn: Convert obsolete cputime type to nsecs
binfmt: Convert obsolete cputime type to nsecs
acct: Convert obsolete cputime type to nsecs
delaycct: Convert obsolete cputime type to nsecs
tsacct: Convert obsolete cputime type to nsecs
signal: Convert obsolete cputime type to nsecs
cputime: Increment kcpustat directly on irqtime account
posix-timers: Use TICK_NSEC instead of a dynamically ad-hoc calculated version
posix-timers: Convert internals to use nsecs
itimer: Convert internal cputime_t units to nsec
sched: Remove temporary cputime_t accessors
cputime: Push time to account_user_time() in nsecs
cputime: Push time to account_steal_time() in nsecs
cputime: Push time to account_idle_time() in nsecs
cputime: Push time to account_system_time() in nsecs
cputime: Complete nsec conversion of tick based accounting
vtime: Return nsecs instead of cputime_t to account
cputime: Remove jiffies based cputime
ia64: Move nsecs based cputime headers to the last arch using it
ia64: Convert vtime to use nsec units directly
ia64: Remove unused cputime definitions
s390: Make arch_cpu_idle_time() to return nsecs
powerpc: Remove unused cputime definitions
s390: Remove unused cputime definitions
cputime: Remove unused nsec_to_cputime
cputime: Remove asm generic headers
arch/alpha/include/asm/Kbuild | 1 -
arch/alpha/kernel/osf_sys.c | 10 +-
arch/arc/include/asm/Kbuild | 1 -
arch/arm/include/asm/Kbuild | 1 -
arch/arm64/include/asm/Kbuild | 1 -
arch/avr32/include/asm/Kbuild | 1 -
arch/blackfin/include/asm/Kbuild | 1 -
arch/c6x/include/asm/Kbuild | 1 -
arch/cris/include/asm/Kbuild | 1 -
arch/frv/include/asm/Kbuild | 1 -
arch/h8300/include/asm/Kbuild | 1 -
arch/hexagon/include/asm/Kbuild | 1 -
arch/ia64/include/asm/cputime.h | 6 +-
arch/ia64/kernel/head.S | 4 +-
arch/ia64/kernel/time.c | 14 +--
arch/m32r/include/asm/Kbuild | 1 -
arch/m68k/include/asm/Kbuild | 1 -
arch/metag/include/asm/Kbuild | 1 -
arch/microblaze/include/asm/Kbuild | 1 -
arch/mips/include/asm/Kbuild | 1 -
arch/mips/kernel/binfmt_elfn32.c | 11 ---
arch/mips/kernel/binfmt_elfo32.c | 11 ---
arch/mn10300/include/asm/Kbuild | 1 -
arch/nios2/include/asm/Kbuild | 1 -
arch/openrisc/include/asm/Kbuild | 1 -
arch/parisc/include/asm/Kbuild | 1 -
arch/parisc/kernel/binfmt_elf32.c | 10 --
arch/powerpc/include/asm/cputime.h | 177 +---------------------------------
arch/powerpc/kernel/time.c | 33 ++-----
arch/s390/appldata/appldata_os.c | 16 +--
arch/s390/include/asm/cputime.h | 109 +--------------------
arch/s390/kernel/idle.c | 7 +-
arch/s390/kernel/vtime.c | 14 +--
arch/score/include/asm/Kbuild | 1 -
arch/sh/include/asm/Kbuild | 1 -
arch/sparc/include/asm/Kbuild | 1 -
arch/tile/include/asm/Kbuild | 1 -
arch/um/include/asm/Kbuild | 1 -
arch/unicore32/include/asm/Kbuild | 1 -
arch/x86/include/asm/Kbuild | 1 -
arch/x86/kernel/apm_32.c | 6 +-
arch/x86/kvm/hyperv.c | 5 +-
arch/xtensa/include/asm/Kbuild | 1 -
drivers/cpufreq/cpufreq.c | 6 +-
drivers/cpufreq/cpufreq_governor.c | 2 +-
drivers/cpufreq/cpufreq_stats.c | 1 -
drivers/isdn/mISDN/stack.c | 4 +-
drivers/macintosh/rack-meter.c | 28 +++---
fs/binfmt_elf.c | 15 +--
fs/binfmt_elf_fdpic.c | 14 +--
fs/compat_binfmt_elf.c | 20 ++--
fs/proc/array.c | 16 +--
fs/proc/stat.c | 64 ++++++------
fs/proc/uptime.c | 7 +-
include/asm-generic/cputime.h | 15 ---
include/asm-generic/cputime_jiffies.h | 75 --------------
include/asm-generic/cputime_nsecs.h | 121 -----------------------
include/linux/cputime.h | 7 +-
include/linux/jiffies.h | 2 +
include/linux/kernel_stat.h | 9 +-
include/linux/posix-timers.h | 14 +--
include/linux/sched.h | 62 +++++-------
include/trace/events/timer.h | 26 ++---
kernel/acct.c | 7 +-
kernel/delayacct.c | 6 +-
kernel/exit.c | 4 +-
kernel/fork.c | 2 +-
kernel/sched/cpuacct.c | 2 +-
kernel/sched/cputime.c | 165 +++++++++++++------------------
kernel/sched/sched.h | 7 +-
kernel/sched/stats.h | 4 +-
kernel/signal.c | 12 +--
kernel/sys.c | 16 +--
kernel/time/itimer.c | 60 ++++--------
kernel/time/jiffies.c | 32 +++---
kernel/time/posix-cpu-timers.c | 170 ++++++++++++--------------------
kernel/time/time.c | 10 ++
kernel/time/timeconst.bc | 6 ++
kernel/tsacct.c | 21 ++--
79 files changed, 408 insertions(+), 1085 deletions(-)