]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
sched: restore deterministic CPU accounting on powerpc
authorPaul Mackerras <paulus@samba.org>
Fri, 9 Nov 2007 21:39:38 +0000 (22:39 +0100)
committerIngo Molnar <mingo@elte.hu>
Fri, 9 Nov 2007 21:39:38 +0000 (22:39 +0100)
commitfa13a5a1f25f671d084d8884be96fc48d9b68275
tree97dae05bb5baef806a6dcbeed8b7eb5bdc61e4ae
parent9a41785cc43d88397f787a651ed7286a33f8462f
sched: restore deterministic CPU accounting on powerpc

Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the
deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been
broken on powerpc, because we end up counting user time twice: once in
timer_interrupt() and once in update_process_times().

This fixes the problem by pulling the code in update_process_times
that updates utime and stime into a separate function called
account_process_tick.  If CONFIG_VIRT_CPU_ACCOUNTING is not defined,
there is a version of account_process_tick in kernel/timer.c that
simply accounts a whole tick to either utime or stime as before.  If
CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to
implement account_process_tick.

This also lets us simplify the s390 code a bit; it means that the s390
timer interrupt can now call update_process_times even when
CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a
suitable account_process_tick().

account_process_tick() now takes the task_struct * as an argument.
Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/powerpc/kernel/process.c
arch/powerpc/kernel/time.c
arch/s390/kernel/time.c
arch/s390/kernel/vtime.c
include/linux/sched.h
kernel/timer.c