KAMEZAWA Hiroyuki 478735e388 /proc/stat: fix scalability of irq sum of all cpu ... In /proc/stat, the number of per-IRQ event is shown by making a sum each irq's events on all cpus. But we can make use of kstat_irqs(). kstat_irqs() do the same calculation, If !CONFIG_GENERIC_HARDIRQ, it's not a big cost. (Both of the number of cpus and irqs are small.) If a system is very big and CONFIG_GENERIC_HARDIRQ, it does for_each_irq() for_each_cpu() - look up a radix tree - read desc->irq_stat[cpu] This seems not efficient. This patch adds kstat_irqs() for CONFIG_GENRIC_HARDIRQ and change the calculation as for_each_irq() look up radix tree for_each_cpu() - read desc->irq_stat[cpu] This reduces cost. A test on (4096cpusp, 256 nodes, 4592 irqs) host (by Jack Steiner) %time cat /proc/stat > /dev/null Before Patch: 2.459 sec After Patch : .561 sec [akpm@linux-foundation.org: unexport kstat_irqs, coding-style tweaks] [akpm@linux-foundation.org: fix unused variable 'per_irq_sum'] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Jack Steiner <steiner@sgi.com> Acked-by: Jack Steiner <steiner@sgi.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2010-10-27 18:03:13 -07:00
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debug	kdb,debug_core: adjust master cpu switch logic against new debug_core locking	2010-10-22 15:34:13 -05:00
gcov	llseek: automatically add .llseek fop	2010-10-15 15:53:27 +02:00
irq	/proc/stat: fix scalability of irq sum of all cpu	2010-10-27 18:03:13 -07:00
power	use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages	2010-10-26 16:52:13 -07:00
time	…
trace	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2010-10-24 13:41:39 -07:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	…
Makefile	Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-10-21 18:52:11 -07:00
acct.c	…
async.c	…
audit.c	…
audit.h	…
audit_tree.c	…
audit_watch.c	…
auditfilter.c	…
auditsc.c	…
backtracetest.c	…
bounds.c	…
capability.c	…
cgroup.c	cgroups: add check for strcpy destination string overflow	2010-10-27 18:03:09 -07:00
cgroup_freezer.c	cgroup_freezer: update_freezer_state() does incorrect state transitions	2010-10-27 18:03:08 -07:00
compat.c	…
configs.c	llseek: automatically add .llseek fop	2010-10-15 15:53:27 +02:00
cpu.c	…
cpuset.c	security: remove unused parameter from security_task_setscheduler()	2010-10-21 10:12:44 +11:00
cred.c	signals: move cred_guard_mutex from task_struct to signal_struct	2010-10-27 18:03:12 -07:00
delayacct.c	…
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	exit: add lock context annotation on find_new_reaper()	2010-10-27 18:03:13 -07:00
extable.c	…
fork.c	signals: move cred_guard_mutex from task_struct to signal_struct	2010-10-27 18:03:12 -07:00
freezer.c	…
futex.c	new helper: ihold()	2010-10-25 21:26:11 -04:00
futex_compat.c	futex: Change 3rd arg of fetch_robust_entry() to unsigned int*	2010-09-18 12:19:21 +02:00
groups.c	…
hrtimer.c	hrtimer: Preserve timer state in remove_hrtimer()	2010-10-14 13:29:59 +02:00
hung_task.c	…
hw_breakpoint.c	perf, hw_breakpoint: Fix crash in hw_breakpoint creation	2010-10-18 19:58:55 +02:00
irq_work.c	irq_work: Add generic hardirq context callbacks	2010-10-18 19:58:50 +02:00
itimer.c	…
jump_label.c	jump label: Add jump_label_text_reserved() to reserve jump points	2010-09-22 16:30:46 -04:00
kallsyms.c	…
kexec.c	use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages	2010-10-26 16:52:13 -07:00
kfifo.c	kfifo: fix scatterlist usage	2010-10-01 10:50:58 -07:00
kmod.c	…
kprobes.c	Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl	2010-10-22 10:52:56 -07:00
ksysfs.c	…
kthread.c	…
latencytop.c	…
lockdep.c	lockdep: Check the depth of subclass	2010-10-18 18:44:26 +02:00
lockdep_internals.h	…
lockdep_proc.c	…
lockdep_states.h	…
module.c	Merge commit 'v2.6.36-rc7' into perf/core	2010-10-08 10:46:27 +02:00
mutex-debug.c	…
mutex-debug.h	…
mutex.c	…
mutex.h	…
notifier.c	…
ns_cgroup.c	cgroup: notify ns_cgroup deprecated	2010-10-27 18:03:09 -07:00
nsproxy.c	…
padata.c	…
panic.c	…
params.c	…
perf_event.c	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-10-21 12:54:49 -07:00
pid.c	…
pid_namespace.c	…
pm_qos_params.c	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2010-10-24 13:41:39 -07:00
posix-cpu-timers.c	…
posix-timers.c	…
printk.c	printk: change type of 'boot_delay' to int *	2010-10-26 16:52:16 -07:00
profile.c	llseek: automatically add .llseek fop	2010-10-15 15:53:27 +02:00
ptrace.c	signals: move cred_guard_mutex from task_struct to signal_struct	2010-10-27 18:03:12 -07:00
range.c	…
rcupdate.c	Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/rcu	2010-10-07 09:43:11 +02:00
rcutiny.c	…
rcutiny_plugin.h	…
rcutorture.c	rcu: fix sparse errors in rcutorture.c	2010-09-23 09:16:42 -07:00
rcutree.c	rcu: using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value	2010-10-07 10:41:06 -07:00
rcutree.h	rcu: Add tracing data to support queueing models	2010-09-23 09:16:53 -07:00
rcutree_plugin.h	…
rcutree_trace.c	rcu: Add tracing data to support queueing models	2010-09-23 09:16:53 -07:00
relay.c	…
res_counter.c	…
resource.c	…
rtmutex-debug.c	…
rtmutex-debug.h	…
rtmutex-tester.c	rtmutex-tester: make it build without BKL	2010-10-19 11:29:56 +02:00
rtmutex.c	…
rtmutex.h	…
rtmutex_common.h	…
rwsem.c	…
sched.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-10-21 12:55:43 -07:00
sched_clock.c	…
sched_cpupri.c	…
sched_cpupri.h	…
sched_debug.c	…
sched_fair.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-10-21 12:55:43 -07:00
sched_features.h	sched: Remove irq time from available CPU power	2010-10-18 20:52:27 +02:00
sched_idletask.c	…
sched_rt.c	sched: Do not account irq time to current task	2010-10-18 20:52:26 +02:00
sched_stats.h	…
sched_stoptask.c	sched: Create special class for stop/migrate work	2010-10-18 18:41:58 +02:00
seccomp.c	…
semaphore.c	…
signal.c	signals: annotate lock context change on ptrace_stop()	2010-10-27 18:03:12 -07:00
smp.c	…
softirq.c	Merge branches 'softirq-for-linus', 'x86-debug-for-linus', 'x86-numa-for-linus', 'x86-quirks-for-linus', 'x86-setup-for-linus', 'x86-uv-for-linus' and 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-10-23 08:25:36 -07:00
spinlock.c	…
srcu.c	kernel: Remove undead ifdef CONFIG_DEBUG_LOCK_ALLOC	2010-09-23 09:14:51 -07:00
stacktrace.c	…
stop_machine.c	stop_machine: convert cpu notifier to return encapsulate errno value	2010-10-26 16:52:15 -07:00
sys.c	…
sys_ni.c	powerpc: define a compat_sys_recv cond_syscall	2010-09-23 17:03:55 +10:00
sysctl.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2010-10-26 17:58:44 -07:00
sysctl_binary.c	…
sysctl_check.c	sysctl: min/max bounds are optional	2010-10-15 14:42:24 -07:00
taskstats.c	…
test_kprobes.c	kprobes: Fix selftest to clear flags field for reusing probes	2010-10-14 08:55:27 +02:00
time.c	…
timeconst.pl	…
timer.c	irq_work: Add generic hardirq context callbacks	2010-10-18 19:58:50 +02:00
tracepoint.c	jump_label: Use more consistent naming	2010-10-18 19:58:56 +02:00
tsacct.c	…
uid16.c	…
up.c	…
user-return-notifier.c	…
user.c	kernel/user.c: add lock release annotation on free_user()	2010-10-26 16:52:15 -07:00
user_namespace.c	…
utsname.c	…
utsname_sysctl.c	…
wait.c	docbook: add more wait/wake/completion to device-drivers docbook	2010-10-26 17:32:41 -07:00
watchdog.c	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-10-21 12:54:49 -07:00
workqueue.c	workqueues: s/ON_STACK/ONSTACK/	2010-10-26 16:52:14 -07:00
workqueue_sched.h	…