1
linux/kernel
Nick Piggin a2000572ad [PATCH] sched: remove smpnice
I don't think the code is quite ready, which is why I asked for Peter's
additions to also be merged before I acked it (although it turned out that
it still isn't quite ready with his additions either).

Basically I have had similar observations to Suresh in that it does not
play nicely with the rest of the balancing infrastructure (and raised
similar concerns in my review).

The samples (group of 4) I got for "maximum recorded imbalance" on a 2x2
SMP+HT Xeon are as follows:

            | Following boot | hackbench 20        | hackbench 40
 -----------+----------------+---------------------+---------------------
 2.6.16-rc2 | 30,37,100,112  | 5600,5530,6020,6090 | 6390,7090,8760,8470
 +nosmpnice |  3, 2,  4,  2  |   28, 150, 294, 132 |  348, 348, 294, 347

Hackbench raw performance is down around 15% with smpnice (but that in
itself isn't a huge deal because it is just a benchmark).  However, the
samples show that the imbalance passed into move_tasks is increased by
about a factor of 10-30.  I think this would also go some way to explaining
latency blips turning up in the balancing code (though I haven't actually
measured that).

We'll probably have to revert this in the SUSE kernel.

Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Williams <pwil3058@bigpond.net.au>
Cc: "Martin J. Bligh" <mbligh@aracnet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-10 08:13:11 -08:00
..
irq [PATCH] kernel/: small cleanups 2006-01-08 20:13:48 -08:00
power [PATCH] Fix build failure in recent pm_prepare_* changes. 2006-02-07 16:12:33 -08:00
.gitignore gitignore: ignore more generated files 2006-01-03 11:35:26 +01:00
acct.c [PATCH] move capable() to capability.h 2006-01-11 18:42:13 -08:00
audit.c [PATCH] EDAC: atomic scrub operations 2006-01-18 19:20:30 -08:00
auditsc.c [PATCH] EDAC: atomic scrub operations 2006-01-18 19:20:30 -08:00
capability.c [PATCH] move capable() to capability.h 2006-01-11 18:42:13 -08:00
compat.c [PATCH] remove bogus asm/bug.h includes. 2006-02-07 20:56:35 -05:00
configs.c update the email address of Randy Dunlap 2006-01-03 13:37:51 +01:00
cpu.c [PATCH] clean up lock_cpu_hotplug() in cpufreq 2005-11-28 14:42:23 -08:00
cpuset.c [PATCH] cpuset: fix sparse warning 2006-02-03 08:32:06 -08:00
dma.c
exec_domain.c
exit.c [PATCH] Unlinline a bunch of other functions 2006-01-14 18:27:06 -08:00
extable.c
fork.c [PATCH] unshare system call -v5: unshare files 2006-02-07 16:12:34 -08:00
futex.c [PATCH] FRV: Make futex code compilable on nommu [try #2] 2006-01-06 08:33:33 -08:00
hrtimer.c [PATCH] hrtimers: add back lost credit lines 2006-02-01 08:53:13 -08:00
intermodule.c [PATCH] missing license tag in intermodule 2006-02-05 11:06:52 -08:00
itimer.c [PATCH] hrtimers: fix oldvalue return in setitimer 2006-02-01 08:53:12 -08:00
kallsyms.c [PATCH] fix missing includes 2005-10-30 17:37:32 -08:00
Kconfig.hz
Kconfig.preempt [PATCH] sched: voluntary kernel preemption 2005-06-25 16:24:45 -07:00
kexec.c [PATCH] move capable() to capability.h 2006-01-11 18:42:13 -08:00
kfifo.c [PATCH] gfp flags annotations - part 1 2005-10-08 15:00:57 -07:00
kmod.c [PATCH] Keys: Get rid of warning in kmod.c if keys disabled 2005-10-30 17:37:23 -08:00
kprobes.c [PATCH] Kprobes: Fix deadlock in function-return probes 2006-02-03 08:32:00 -08:00
ksysfs.c [PATCH] kdump: export per cpu crash notes pointer through sysfs 2006-01-10 08:01:26 -08:00
kthread.c [PATCH] Add kthread_stop_sem() 2005-10-30 17:37:17 -08:00
Makefile [PATCH] build kernel/intermodule.c only when required 2006-01-16 23:15:26 -08:00
module.c [PATCH] module: strlen_user() race fix 2006-02-07 16:12:32 -08:00
mutex-debug.c [PATCH] fix/simplify mutex debugging code 2006-01-11 08:14:16 -08:00
mutex-debug.h [PATCH] mutex subsystem, debugging code 2006-01-09 15:59:20 -08:00
mutex.c [PATCH] mutex: trivial whitespace cleanups 2006-01-10 14:27:59 -08:00
mutex.h [PATCH] mutex subsystem, core 2006-01-09 15:59:19 -08:00
panic.c [PATCH] s390: cleanup Kconfig 2006-01-06 08:33:53 -08:00
params.c [PATCH] kernel/params.c: fix sysfs access with CONFIG_MODULES=n 2005-12-20 10:31:33 -08:00
pid.c [PATCH] RCU signal handling 2006-01-08 20:13:40 -08:00
posix-cpu-timers.c [PATCH] hrtimer: switch clock_nanosleep to hrtimer nanosleep API 2006-01-10 08:01:38 -08:00
posix-timers.c [PATCH] kernel/posix-timers.c: remove do_posix_clock_notimer_create() 2006-02-01 08:53:13 -08:00
printk.c correct email address of Manfred Spraul 2006-01-15 02:43:54 +01:00
profile.c [PATCH] mostly_read data section 2005-07-07 18:23:46 -07:00
ptrace.c [PATCH] move capable() to capability.h 2006-01-11 18:42:13 -08:00
rcupdate.c [PATCH] rcu: fix hotplug-cpu ->donelist leak 2006-01-10 08:49:47 -08:00
rcutorture.c [PATCH] rcu_torture_lock deadlock fix 2006-01-31 11:30:18 -08:00
resource.c [PATCH] kernel/resource.c: __check_region(): remove pointless __deprecated 2006-01-10 08:02:02 -08:00
sched.c [PATCH] sched: remove smpnice 2006-02-10 08:13:11 -08:00
seccomp.c
signal.c [PATCH] do_sigaction: cleanup ->sa_mask manipulation 2006-02-09 16:17:36 -08:00
softirq.c [PATCH] cpu hoptlug: avoid usage of smp_processor_id() in preemptible code 2005-11-07 07:53:29 -08:00
softlockup.c [PATCH] quieten softlockup at boot 2005-11-09 07:55:50 -08:00
spinlock.c [PATCH] spinlock consolidation 2005-09-10 10:06:21 -07:00
stop_machine.c [PATCH] Remove set_fs() in stop_machine() 2006-01-10 08:01:25 -08:00
sys_ni.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge 2006-01-09 10:03:44 -08:00
sys.c [PATCH] kernel/sys.c NULL noise removal 2006-02-07 20:57:47 -05:00
sysctl.c [PATCH] zone_reclaim: configurable off node allocation period. 2006-02-01 08:53:16 -08:00
time.c [PATCH] Normalize timespec for negative values in ns_to_timespec 2006-02-03 08:32:06 -08:00
timer.c [PATCH] timer.c NULL noise removal 2006-02-07 20:57:42 -05:00
uid16.c [PATCH] move capable() to capability.h 2006-01-11 18:42:13 -08:00
user.c [PATCH] "Fix uidhash_lock <-> RXU deadlock" fix 2006-01-31 16:49:43 -08:00
wait.c
workqueue.c [PATCH] Unlinline a bunch of other functions 2006-01-14 18:27:06 -08:00