linux/kernel
Peter Williams 615052dc3b [PATCH] sched: Avoid unnecessarily moving highest priority task move_tasks()
Problem:

To help distribute high priority tasks evenly across the available CPUs
move_tasks() does not, under some circumstances, skip tasks whose load
weight is bigger than the designated amount.  Because the highest priority
task on the busiest queue may be on the expired array it may be moved as a
result of this mechanism.  Apart from not being the most desirable way to
redistribute the high priority tasks (we'd rather move the second highest
priority task), there is a risk that this could set up a loop with this
task bouncing backwards and forwards between the two queues.  (This latter
possibility can be demonstrated by running a nice==-20 CPU bound task on an
otherwise quiet 2 CPU system.)

Solution:

Modify the mechanism so that it does not override skip for the highest
priority task on the CPU.  Of course, if there are more than one tasks at
the highest priority then it will allow the override for one of them as
this is a desirable redistribution of high priority tasks.

Signed-off-by: Peter Williams <pwil3058@bigpond.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:44 -07:00
..
irq [PATCH] adjust handle_IRR_event() return type 2006-06-23 07:43:08 -07:00
power [PATCH] pm_trace is dangerous 2006-06-27 17:32:35 -07:00
time [PATCH] time: rename clocksource functions 2006-06-26 09:58:21 -07:00
.gitignore gitignore: ignore more generated files 2006-01-03 11:35:26 +01:00
acct.c [PATCH] fix kernel-doc in kernel/ dir 2006-06-27 17:32:39 -07:00
audit.c [PATCH] spin/rwlock init cleanups 2006-06-27 17:32:39 -07:00
audit.h [PATCH] log more info for directory entry change events 2006-06-20 05:25:28 -04:00
auditfilter.c [PATCH] log more info for directory entry change events 2006-06-20 05:25:28 -04:00
auditsc.c [PATCH] fix kernel-doc in kernel/ dir 2006-06-27 17:32:39 -07:00
capability.c [PATCH] refactor capable() to one implementation, add __capable() helper 2006-03-25 08:22:56 -08:00
compat.c [PATCH] N32 sigset and __COMPAT_ENDIAN_SWAP__ 2006-06-25 10:01:15 -07:00
configs.c update the email address of Randy Dunlap 2006-01-03 13:37:51 +01:00
cpu.c [PATCH] cpu hotplug: make [un]register_cpu_notifier init time only 2006-06-27 17:32:41 -07:00
cpuset.c [PATCH] proc: Use struct pid not struct task_ref 2006-06-26 09:58:26 -07:00
dma.c
exec_domain.c [PATCH] Fix module refcount leak in __set_personality() 2006-03-24 07:33:30 -08:00
exit.c [PATCH] proc: Rewrite the proc dentry flush on exit optimization 2006-06-26 09:58:24 -07:00
extable.c [PATCH] symbol_put_addr() locks kernel 2006-05-15 11:20:55 -07:00
fork.c [PATCH] coredump: copy_process: don't check SIGNAL_GROUP_EXIT 2006-06-26 09:58:27 -07:00
futex_compat.c [PATCH] futex: check and validate timevals 2006-03-31 12:18:59 -08:00
futex.c [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
hrtimer.c [PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17 2006-06-27 17:32:41 -07:00
itimer.c [PATCH] hrtimers: remove data field 2006-03-26 08:57:03 -08:00
kallsyms.c [PATCH] fix missing includes 2005-10-30 17:37:32 -08:00
Kconfig.hz
Kconfig.preempt
kexec.c [PATCH] Add a sysfs file to determine if a kexec kernel is loaded 2006-06-23 07:43:02 -07:00
kfifo.c
kmod.c [PATCH] wait_for_helper: trivial style cleanup 2006-03-28 18:36:41 -08:00
kprobes.c [PATCH] Notify page fault call chain 2006-06-26 09:58:22 -07:00
ksysfs.c [PATCH] Add a sysfs file to determine if a kexec kernel is loaded 2006-06-23 07:43:02 -07:00
kthread.c [PATCH] kthread: move kernel-doc and put it into DocBook 2006-06-25 10:01:24 -07:00
Makefile Merge branch 'x86-64' 2006-06-26 10:51:09 -07:00
module.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild 2006-06-26 11:05:15 -07:00
mutex-debug.c [PATCH] poison: add & use more constants 2006-06-27 17:32:38 -07:00
mutex-debug.h [PATCH] work around ppc64 bootup bug by making mutex-debugging save/restore irqs 2006-06-26 09:58:16 -07:00
mutex.c [PATCH] work around ppc64 bootup bug by making mutex-debugging save/restore irqs 2006-06-26 09:58:16 -07:00
mutex.h [PATCH] work around ppc64 bootup bug by making mutex-debugging save/restore irqs 2006-06-26 09:58:16 -07:00
panic.c [PATCH] the scheduled unexport of panic_timeout 2006-04-11 06:18:40 -07:00
params.c [PATCH] Change dash2underscore() return value to char 2006-03-28 09:16:03 -08:00
pid.c [PATCH] pidhash: Refactor the pid hash table 2006-03-31 12:19:00 -08:00
posix-cpu-timers.c [PATCH] arm_timer: remove a racy and obsolete PF_EXITING check 2006-06-17 10:52:13 -07:00
posix-timers.c [PATCH] hrtimers: remove data field 2006-03-26 08:57:03 -08:00
printk.c [PATCH] printk time parameter 2006-06-25 10:01:13 -07:00
profile.c [PATCH] cpu hotplug: revert init patch submitted for 2.6.17 2006-06-27 17:32:40 -07:00
ptrace.c [PATCH] coredump: kill ptrace related stuff 2006-06-26 09:58:27 -07:00
rcupdate.c [PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17 2006-06-27 17:32:41 -07:00
rcutorture.c [PATCH] rcutorture: add call_rcu_bh() operations 2006-06-27 17:32:40 -07:00
relay.c [PATCH] relay: consolidate sendfile() and read() code 2006-03-23 19:58:45 +01:00
resource.c [PATCH] catch valid mem range at onlining memory 2006-06-27 17:32:36 -07:00
sched.c [PATCH] sched: Avoid unnecessarily moving highest priority task move_tasks() 2006-06-27 17:32:44 -07:00
seccomp.c
signal.c [PATCH] coredump: kill ptrace related stuff 2006-06-26 09:58:27 -07:00
softirq.c [PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17 2006-06-27 17:32:41 -07:00
softlockup.c [PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17 2006-06-27 17:32:41 -07:00
spinlock.c [PATCH] BUILD_LOCK_OPS: cleanup preempt_disable() usage 2006-03-23 07:38:16 -08:00
stop_machine.c [PATCH] kthread: convert stop_machine into a kthread 2006-06-25 10:01:22 -07:00
sys_ni.c [PATCH] sys_move_pages: 32bit support (i386, x86_64) 2006-06-23 07:42:53 -07:00
sys.c [PATCH] kernel/sys.c: cleanups 2006-06-25 10:01:06 -07:00
sysctl.c [PATCH] vdso: randomize the i386 vDSO by moving it into a vma 2006-06-27 17:32:38 -07:00
time.c [PATCH] Time: Introduce arch generic time accessors 2006-06-26 09:58:20 -07:00
timer.c [PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17 2006-06-27 17:32:41 -07:00
uid16.c [PATCH] Add more prevent_tail_call() 2006-04-19 16:27:18 -07:00
unwind.c [PATCH] x86_64: allow unwinder to build without module support 2006-06-26 10:48:18 -07:00
user.c [PATCH] selinux: add hooks for key subsystem 2006-06-22 15:05:55 -07:00
wait.c
workqueue.c [PATCH] cpu hotplug: revert init patch submitted for 2.6.17 2006-06-27 17:32:40 -07:00