[PATCH 0/4] cputime: some optimizations and cleanups
flat view
STALE3642d
From: Stanislaw Gruszka <hidden>
Date: 2016-10-31 12:37:55
Also in:
linux-s390, lkml
Subsystem:
apm driver, exec & binfmt api, elf, generic include/asm header files, linux for powerpc (32-bit and 64-bit), memory management - core, posix clocks and timers, s390 architecture, scheduler, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Jiri Kosina, Kees Cook, Arnd Bergmann, Madhavan Srinivasan, Andrew Morton, David Hildenbrand, Anna-Maria Behnsen, Frederic Weisbecker, Thomas Gleixner, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds, Borislav Petkov, Dave Hansen
Patches remove accounting of utimescaled/stimescaled on architectures that do not provide those values (scaled cputimes are equal to normal cputimes) what is every architecture except powerpc and s390. Patches do not change user visible behaviour. There is very little documentation how scaled cputimes should be interpreted and what useful information they provide (at least I could not find that). Moreover they are exported to user-space only via not commonly used taskstats and delayacct interfaces (i.e. interfaces that are not used by standard linux tools AFICT). However I assume they can not be removed by whole (i.e. replaced by normal utimes/stimes on powerpc and s390). Stanislaw Gruszka (4): cputime/powerpc: remove cputime_last_delta global variable cputime/powerpc: remove cputime_to_scaled() cputime/powerpc/s390: make scaled cputime arch specific cputime: simplify task_cputime() arch/ia64/kernel/time.c | 4 +- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/cputime.h | 14 ---- arch/powerpc/kernel/time.c | 8 +- arch/s390/Kconfig | 1 + arch/s390/kernel/vtime.c | 9 ++- arch/x86/kernel/apm_32.c | 4 +- include/asm-generic/cputime_jiffies.h | 1 - include/asm-generic/cputime_nsecs.h | 1 - include/linux/kernel_stat.h | 4 +- include/linux/sched.h | 29 +++++--- kernel/fork.c | 2 + kernel/sched/cputime.c | 124 +++++++++------------------------ kernel/time/posix-cpu-timers.c | 4 +- 14 files changed, 73 insertions(+), 133 deletions(-)