Nick Piggin ff91691bcc [PATCH] sched: avoid div in rebalance_tick ...

Avoid expensive integer divide 3 times per CPU per tick.

A userspace test of this loop went from 26ns, down to 19ns on a G5; and
from 123ns down to 28ns on a P3.

(Also avoid a variable bit shift, as suggested by Alan. The effect
of this wasn't noticable on the CPUs I tested with).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2007-02-12 09:48:37 -08:00

..

irq

[PATCH] kernel: shut up the IRQ mismatch messages

2007-02-12 09:48:28 -08:00

power

[PATCH] swsusp: Change pm_ops handling by userland interface

2007-02-11 10:51:20 -08:00

time

[PATCH] kernel/time/clocksource.c needs struct task_struct on m68k

2007-02-11 10:51:20 -08:00

.gitignore

gitignore: ignore more generated files

2006-01-03 11:35:26 +01:00

acct.c

[PATCH] kernel: change uses of f_{dentry, vfsmnt} to use f_path

2006-12-08 08:28:42 -08:00

audit.c

[PATCH] Add include/linux/freezer.h and move definitions from sched.h

2006-12-07 08:39:27 -08:00

audit.h

[PATCH] audit: AUDIT_PERM support

2006-09-11 13:32:30 -04:00

auditfilter.c

[PATCH] audit: fix audit_filter_user_rules() initialization bug

2007-02-11 10:51:34 -08:00

auditsc.c

[PATCH] struct path: convert kernel

2006-12-08 08:28:46 -08:00

capability.c

[PATCH] pid: replace do/while_each_task_pid with do/while_each_pid_task

2007-02-12 09:48:32 -08:00

compat.c

[PATCH] Common compat_sys_sysinfo

2007-02-11 10:51:32 -08:00

configs.c

[PATCH] struct seq_operations and struct file_operations constification

2006-12-07 08:39:46 -08:00

cpu.c

[PATCH] swsusp: Change code ordering in disk.c

2007-02-11 10:51:19 -08:00

cpuset.c

[PATCH] cpuset procfs warning fix

2006-12-30 10:56:43 -08:00

delayacct.c

[PATCH] slab: remove kmem_cache_t

2006-12-07 08:39:25 -08:00

dma.c

[PATCH] struct seq_operations and struct file_operations constification

2006-12-07 08:39:46 -08:00

exec_domain.c

Remove obsolete #include <linux/config.h>

2006-06-30 19:25:36 +02:00

exit.c

[PATCH] pid: replace is_orphaned_pgrp with is_current_pgrp_orphaned

2007-02-12 09:48:32 -08:00

extable.c

[PATCH] symbol_put_addr() locks kernel

2006-05-15 11:20:55 -07:00

fork.c

[PATCH] tty: update the tty layer to work with struct pid

2007-02-12 09:48:32 -08:00

futex_compat.c

[PATCH] __user annotations: futex

2006-10-10 15:37:22 -07:00

futex.c

[PATCH] kernel: change uses of f_{dentry, vfsmnt} to use f_path

2006-12-08 08:28:42 -08:00

hrtimer.c

[PATCH] Numerous fixes to kernel-doc info in source files.

2007-02-11 10:51:32 -08:00

itimer.c

[PATCH] hrtimers: remove data field

2006-03-26 08:57:03 -08:00

kallsyms.c

[PATCH] move kallsyms data to .rodata

2006-12-08 08:28:37 -08:00

Kconfig.hz

[PATCH] HZ: 300Hz support

2006-12-07 08:39:36 -08:00

Kconfig.preempt

[PATCH] sched: voluntary kernel preemption

2005-06-25 16:24:45 -07:00

kexec.c

Merge branch 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6

2006-12-07 15:39:22 -08:00

kfifo.c

[PATCH] Numerous fixes to kernel-doc info in source files.

2007-02-11 10:51:32 -08:00

kmod.c

[PATCH] rename struct namespace to struct mnt_namespace

2006-12-08 08:28:51 -08:00

kprobes.c

[PATCH] kprobes: replace magic numbers with enum

2007-01-30 16:01:35 -08:00

ksysfs.c

Remove obsolete #include <linux/config.h>

2006-06-30 19:25:36 +02:00

kthread.c

[PATCH] Numerous fixes to kernel-doc info in source files.

2007-02-11 10:51:32 -08:00

latency.c

[PATCH] severing module.h->sched.h

2006-12-04 02:00:22 -05:00

lockdep_internals.h

[PATCH] lockdep: more chains

2006-12-07 08:39:43 -08:00

lockdep_proc.c

[PATCH] Fix apparent typo CONFIG_LOCKDEP_DEBUG

2007-02-11 11:18:06 -08:00

lockdep.c

[PATCH] lockdep: add graph depth information to /proc/lockdep

2007-02-11 10:51:26 -08:00

Makefile

Remove stack unwinder for now

2006-12-15 08:47:51 -08:00

module.c

/sys/modules/*/holders

2007-02-07 10:37:12 -08:00

mutex-debug.c

[PATCH] lockdep: show more details about self-test failures

2006-12-07 08:39:43 -08:00

mutex-debug.h

[PATCH] lockdep: better lock debugging

2006-07-03 15:27:01 -07:00

mutex.c

[PATCH] lockdep: avoid lockdep warning in md

2006-12-08 08:28:39 -08:00

mutex.h

[PATCH] lockdep: prove mutex locking correctness

2006-07-03 15:27:04 -07:00

nsproxy.c

Revert "[PATCH] namespaces: fix exit race by splitting exit"

2007-01-30 13:35:18 -08:00

panic.c

[PATCH] Add TAINT_USER and ability to set taint flags from userspace

2007-02-11 10:51:29 -08:00

params.c

/sys/modules/*/holders

2007-02-07 10:37:12 -08:00

pid.c

[PATCH] namespaces: fix task exit disaster

2007-01-30 13:40:36 -08:00

posix-cpu-timers.c

[PATCH] posix-cpu-timers: prevent signal delivery starvation

2006-10-17 08:18:43 -07:00

posix-timers.c

[PATCH] Transform kmem_cache_alloc()+memset(0) -> kmem_cache_zalloc().

2007-02-11 10:51:27 -08:00

printk.c

[PATCH] order of lockdep off/on in vprintk() should be changed

2007-02-11 11:18:06 -08:00

profile.c

[PATCH] proc: remove useless (and buggy) ->nlink settings

2007-02-11 10:51:32 -08:00

ptrace.c

[PATCH] pidspace: is_init()

2006-09-29 09:18:12 -07:00

rcupdate.c

[PATCH] rcu: add a prefetch() in rcu_do_batch()

2006-12-07 08:39:40 -08:00

rcutorture.c

[PATCH] rcu: rcutorture suspend fix

2006-12-30 10:55:55 -08:00

relay.c

[PATCH] Numerous fixes to kernel-doc info in source files.

2007-02-11 10:51:32 -08:00

resource.c

devres: device resource management

2007-02-09 17:39:36 -05:00

rtmutex_common.h

[PATCH] pi-futex: futex_lock_pi/futex_unlock_pi support

2006-06-27 17:32:47 -07:00

rtmutex-debug.c

Remove all inclusions of <linux/config.h>

2006-10-04 03:38:54 -04:00

rtmutex-debug.h

[PATCH] lockdep: better lock debugging

2006-07-03 15:27:01 -07:00

rtmutex-tester.c

[PATCH] Add include/linux/freezer.h and move definitions from sched.h

2006-12-07 08:39:27 -08:00

rtmutex.c

[PATCH] clean up and remove some extra spinlocks from rtmutex

2006-09-29 09:18:09 -07:00

rtmutex.h

[PATCH] lockdep: better lock debugging

2006-07-03 15:27:01 -07:00

rwsem.c

[PATCH] lockdep: prove rwsem locking correctness

2006-07-03 15:27:04 -07:00

sched.c

[PATCH] sched: avoid div in rebalance_tick

2007-02-12 09:48:37 -08:00

seccomp.c

Linux-2.6.12-rc2

2005-04-16 15:20:36 -07:00

signal.c

[PATCH] pid: remove the now unused kill_pg kill_pg_info and __kill_pg_info

2007-02-12 09:48:32 -08:00

softirq.c

[PATCH] softirq: remove BUG_ONs which can incorrectly trigger

2006-12-07 08:39:43 -08:00

softlockup.c

[PATCH] check return value of cpu_callback

2006-09-29 09:18:14 -07:00

spinlock.c

[PATCH] lockdep: spin_lock_irqsave_nested()

2006-11-25 13:28:34 -08:00

srcu.c

[PATCH] SRCU: report out-of-memory errors

2006-10-04 07:55:30 -07:00

stacktrace.c

[PATCH] lockdep: stacktrace subsystem, core

2006-07-03 15:27:02 -07:00

stop_machine.c

[PATCH] stop_machine.c copyright

2006-09-29 09:18:24 -07:00

sys_ni.c

[PATCH] Create compat_sys_migrate_pages

2006-11-03 12:27:59 -08:00

sys.c

[PATCH] pid: replace do/while_each_task_pid with do/while_each_pid_task

2007-02-12 09:48:32 -08:00

sysctl.c

[PATCH] _proc_do_string(): fix short reads

2007-02-11 11:18:07 -08:00

taskstats.c

[PATCH] taskstats: cleanup reply assembling

2006-12-07 08:39:34 -08:00

time.c

[PATCH] NTP: Move all the NTP related code to ntp.c

2006-10-01 00:39:26 -07:00

timer.c

[PATCH] Common compat_sys_sysinfo

2007-02-11 10:51:32 -08:00

tsacct.c

[PATCH] io-accounting: via taskstats

2006-12-10 09:55:41 -08:00

uid16.c

[PATCH] Add more prevent_tail_call()

2006-04-19 16:27:18 -07:00

user.c

[PATCH] slab: remove kmem_cache_t

2006-12-07 08:39:25 -08:00

utsname.c

[PATCH] namespaces: utsname: implement CLONE_NEWUTS flag

2006-10-02 07:57:22 -07:00

wait.c

[PATCH] uninline init_waitqueue_head()

2006-07-10 13:24:25 -07:00

workqueue.c

[PATCH] Numerous fixes to kernel-doc info in source files.

2007-02-11 10:51:32 -08:00