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

…

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

…

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

…

exit.c

[PATCH] pid: replace is_orphaned_pgrp with is_current_pgrp_orphaned

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

extable.c

…

fork.c

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

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

futex_compat.c

…

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

…

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

…

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

…

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

…

mutex.c

[PATCH] lockdep: avoid lockdep warning in md

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

mutex.h

…

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

…

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

…

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

…

rtmutex-debug.c

…

rtmutex-debug.h

…

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

…

rtmutex.h

…

rwsem.c

…

sched.c

[PATCH] sched: avoid div in rebalance_tick

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

seccomp.c

…

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

…

spinlock.c

…

srcu.c

…

stacktrace.c

…

stop_machine.c

…

sys_ni.c

…

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

…

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

…

user.c

[PATCH] slab: remove kmem_cache_t

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

utsname.c

…

wait.c

…

workqueue.c

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

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