linux/kernel
Ken Chen 720f54988e sched, cpuacct: refactoring cpuusage_read / cpuusage_write
Impact: micro-optimize the code on 64-bit architectures

In the thread regarding to 'export percpu cpuacct cgroup stats'
http://lkml.org/lkml/2008/12/7/13

akpm pointed out that current cpuacct code is inefficient.  This patch
refactoring the following:

* make cpu_rq locking only on 32-bit
* change iterator to each_present_cpu instead of each_possible_cpu to
  make it hotplug friendly.

It's a bit of code churn, but I was rewarded with 160 byte code size saving
on x86-64 arch and zero code size change on i386.

Signed-off-by: Ken Chen <kenchen@google.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 12:15:00 +01:00
..
irq genirq: __irq_set_trigger: change pr_warning to pr_debug 2008-11-13 11:59:48 +01:00
power [PATCH] kill obsolete temporary comment in swsusp_close() 2008-12-04 04:22:54 -05:00
time time: catch xtime_nsec underflows and fix them 2008-12-04 08:43:02 +01:00
trace ftrace: prevent recursion 2008-11-27 10:11:53 +01:00
.gitignore
acct.c
audit_tree.c Fix inotify watch removal/umount races 2008-11-15 12:26:44 -08:00
audit.c [PATCH] fix broken timestamps in AVC generated by kernel threads 2008-12-09 02:27:41 -05:00
audit.h
auditfilter.c Fix inotify watch removal/umount races 2008-11-15 12:26:44 -08:00
auditsc.c [PATCH] fix broken timestamps in AVC generated by kernel threads 2008-12-09 02:27:41 -05:00
backtracetest.c
bounds.c
capability.c
cgroup_debug.c cgroups: fix probable race with put_css_set[_taskexit] and find_css_set 2008-10-20 08:52:38 -07:00
cgroup_freezer.c freezer_cg: disable writing freezer.state of root cgroup 2008-11-12 17:17:16 -08:00
cgroup.c cgroups: fix a serious bug in cgroupstats 2008-11-19 18:50:00 -08:00
compat.c Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', 'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus 2008-10-20 13:14:06 +02:00
configs.c kernel/configs.c: remove useless comments 2008-10-20 08:52:34 -07:00
cpu.c cpuinit fixes in kernel/* 2008-11-30 10:03:37 -08:00
cpuset.c sched, cpusets: fix warning in kernel/cpuset.c 2008-11-29 20:39:29 +01:00
delayacct.c
dma-coherent.c
dma.c kernel/dma.c: remove a CVS keyword 2008-10-16 11:21:30 -07:00
exec_domain.c proc: move /proc/execdomains to kernel/exec_domain.c 2008-10-23 14:30:41 +04:00
exit.c Move "exit_robust_list" into mm_release() 2008-11-15 10:20:36 -08:00
extable.c
fork.c fix mapping_writably_mapped() 2008-12-10 14:40:45 -08:00
freezer.c freezer_cg: use thaw_process() in unfreeze_cgroup() 2008-10-30 11:38:45 -07:00
futex_compat.c
futex.c
hrtimer.c hrtimer: clean up unused callback modes 2008-11-12 09:54:40 +01:00
itimer.c
kallsyms.c sprint_symbol(): use less stack 2008-11-19 18:49:58 -08:00
Kconfig.freezer container freezer: implement freezer cgroup subsystem 2008-10-20 08:52:34 -07:00
Kconfig.hz
Kconfig.preempt
kexec.c kexec: fix crash_save_vmcoreinfo_init build problem 2008-10-20 15:28:50 -07:00
kfifo.c
kgdb.c
kmod.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus 2008-10-16 12:38:34 -07:00
kprobes.c kernel/kprobes.c: don't pad kretprobe_table_locks[] on uniprocessor builds 2008-11-12 17:17:17 -08:00
ksysfs.c profiling: dynamically enable readprofile at runtime 2008-10-16 11:21:31 -07:00
kthread.c Merge branch 'tracing-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-10-20 13:35:07 -07:00
latencytop.c KSYM_SYMBOL_LEN fixes 2008-12-10 08:01:54 -08:00
lockdep_internals.h
lockdep_proc.c
lockdep.c lockdep: consistent alignement for lockdep info 2008-11-21 08:59:40 +01:00
Makefile Merge branch 'linus' into sched/core 2008-11-19 09:44:37 +01:00
marker.c
module.c Merge branch 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc 2008-10-23 12:04:37 -07:00
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
panic.c taint: add missing comment 2008-12-01 19:55:24 -08:00
params.c Fix compile warning in kernel/params.c 2008-10-23 12:09:00 -07:00
pid_namespace.c
pid.c
pm_qos_params.c
posix-cpu-timers.c posix-cpu-timers: fix clock_gettime with CLOCK_PROCESS_CPUTIME_ID 2008-11-24 16:41:40 +01:00
posix-timers.c Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2 2008-10-22 09:48:06 +02:00
printk.c printk: remove unused code from kernel/printk.c 2008-10-23 21:54:29 +02:00
profile.c cpuinit fixes in kernel/* 2008-11-30 10:03:37 -08:00
ptrace.c remove __ARCH_WANT_COMPAT_SYS_PTRACE 2008-11-30 11:00:15 -08:00
rcuclassic.c
rcupdate.c rcupdate: fix bug of rcu_barrier*() 2008-10-21 15:59:53 +02:00
rcupreempt_trace.c
rcupreempt.c byteorder: remove direct includes of linux/byteorder/swab[b].h 2008-10-20 08:52:40 -07:00
rcutorture.c byteorder: remove direct includes of linux/byteorder/swab[b].h 2008-10-20 12:51:53 -07:00
relay.c relayfs: fix infinite loop with splice() 2008-12-10 08:01:52 -08:00
res_counter.c
resource.c reserve_region_with_split: Fix GFP_KERNEL usage under spinlock 2008-11-01 09:53:58 -07:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c
sched_cpupri.c
sched_cpupri.h
sched_debug.c sched: add uid information to sched_debug for CONFIG_USER_SCHED 2008-12-01 20:39:50 +01:00
sched_fair.c sched: optimize update_curr() 2008-12-16 09:46:33 +01:00
sched_features.h sched: backward looking buddy 2008-11-05 10:30:14 +01:00
sched_idletask.c sched: add CONFIG_SMP consistency 2008-10-22 10:01:52 +02:00
sched_rt.c sched: move double_unlock_balance() higher 2008-11-28 20:11:15 +01:00
sched_stats.h sched, signals: fix the racy usage of ->signal in account_group_xxx/run_posix_cpu_timers 2008-11-17 16:49:35 +01:00
sched.c sched, cpuacct: refactoring cpuusage_read / cpuusage_write 2008-12-16 12:15:00 +01:00
seccomp.c
semaphore.c
signal.c 'kill sig -1' must only apply to caller's namespace 2008-10-30 11:38:46 -07:00
smp.c generic-ipi: fix the smp_mb() placement 2008-11-06 08:41:56 +01:00
softirq.c irq: call __irq_enter() before calling the tick_idle_check 2008-11-10 22:36:39 +01:00
softlockup.c check_hung_task(): unsigned sysctl_hung_task_warnings cannot be less than 0 2008-12-03 10:11:51 +01:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c stop_machine: fix race with return value (fixes Bug #11989) 2008-11-16 15:09:52 -08:00
sys_ni.c reintroduce accept4 2008-11-19 18:49:57 -08:00
sys.c Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2 2008-10-22 09:48:06 +02:00
sysctl_check.c
sysctl.c epoll: introduce resource usage limits 2008-12-01 19:55:24 -08:00
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c Add round_jiffies_up and related routines 2008-11-06 08:42:48 +01:00
tracepoint.c tracepoint: check if the probe has been registered 2008-10-27 16:45:46 +01:00
tsacct.c
uid16.c
user_namespace.c
user.c sched: add uid information to sched_debug for CONFIG_USER_SCHED 2008-12-01 20:39:50 +01:00
utsname_sysctl.c sysctl: simplify ->strategy 2008-10-16 11:21:47 -07:00
utsname.c
wait.c wait: kill is_sync_wait() 2008-10-16 11:21:31 -07:00
workqueue.c cpumask: introduce new API, without changing anything 2008-11-06 09:05:33 +01:00