Linus Torvalds 37407ea7f9 Revert "sched: Improve scalability via 'CPU buddies', which withstand random perturbations" ... This reverts commit 970e178985. Nikolay Ulyanitsky reported thatthe 3.6-rc5 kernel has a 15-20% performance drop on PostgreSQL 9.2 on his machine (running "pgbench"). Borislav Petkov was able to reproduce this, and bisected it to this commit 970e178985 ("sched: Improve scalability via 'CPU buddies' ...") apparently because the new single-idle-buddy model simply doesn't find idle CPU's to reschedule on aggressively enough. Mike Galbraith suspects that it is likely due to the user-mode spinlocks in PostgreSQL not reacting well to preemption, but we don't really know the details - I'll just revert the commit for now. There are hopefully other approaches to improve scheduler scalability without it causing these kinds of downsides. Reported-by: Nikolay Ulyanitsky <lystor@gmail.com> Bisected-by: Borislav Petkov <bp@alien8.de> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2012-09-16 12:29:43 -07:00
..
debug	kernel/debug: Make use of KGDB_REASON_NMI	2012-07-31 08:16:43 -05:00
events	perf/hwpb: Invoke __perf_event_disable() if interrupts are already disabled	2012-09-04 17:29:53 +02:00
gcov	…
irq	Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-08-03 10:56:44 -07:00
power	Revert "NMI watchdog: fix for lockup detector breakage on resume"	2012-08-08 20:49:45 +02:00
sched	Revert "sched: Improve scalability via 'CPU buddies', which withstand random perturbations"	2012-09-16 12:29:43 -07:00
time	sched: Add missing call to calc_load_exit_idle()	2012-09-04 14:30:29 +02:00
trace	tracing/syscalls: Fix perf syscall tracing when syscall_nr == -1	2012-08-17 15:19:46 -04:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	…
Makefile	…
acct.c	…
async.c	[SCSI] async: make async_synchronize_full() flush all work regardless of domain	2012-07-20 09:07:37 +01:00
audit.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2012-08-01 10:26:23 -07:00
audit.h	…
audit_tree.c	audit: clean up refcounting in audit-tree	2012-08-15 12:55:22 +02:00
audit_watch.c	…
auditfilter.c	…
auditsc.c	…
backtracetest.c	…
bounds.c	…
capability.c	…
cgroup.c	Merge branch 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2012-07-24 17:47:44 -07:00
cgroup_freezer.c	…
compat.c	…
configs.c	…
cpu.c	mm/hotplug: correctly setup fallback zonelists when creating new pgdat	2012-07-31 18:42:44 -07:00
cpu_pm.c	…
cpuset.c	cpusets: Remove/update outdated comments	2012-07-24 13:53:28 +02:00
crash_dump.c	…
cred.c	…
delayacct.c	…
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	posix_types.h: Cleanup stale __NFDBITS and related definitions	2012-07-26 13:36:43 -07:00
extable.c	…
fork.c	uprobes: Fix mmap_region()'s mm->mm_rb corruption if uprobe_mmap() fails	2012-08-21 11:48:12 +02:00
freezer.c	…
futex.c	futex: Forbid uaddr == uaddr2 in futex_wait_requeue_pi()	2012-07-24 16:02:57 +02:00
futex_compat.c	…
groups.c	…
hrtimer.c	…
hung_task.c	…
irq_work.c	…
itimer.c	…
jump_label.c	…
kallsyms.c	…
kcmp.c	…
kexec.c	kdump: append newline to the last lien of vmcoreinfo note	2012-07-30 17:25:20 -07:00
kfifo.c	…
kmod.c	kmod: avoid deadlock from recursive kmod call	2012-07-30 17:25:20 -07:00
kprobes.c	…
ksysfs.c	…
kthread.c	kthread_worker: reimplement flush_kthread_work() to allow freeing the work item being executed	2012-07-22 10:15:28 -07:00
latencytop.c	…
lglock.c	…
lockdep.c	…
lockdep_internals.h	…
lockdep_proc.c	…
lockdep_states.h	…
module.c	…
mutex-debug.c	…
mutex-debug.h	…
mutex.c	…
mutex.h	…
notifier.c	…
nsproxy.c	…
padata.c	…
panic.c	panic: fix a possible deadlock in panic()	2012-07-30 17:25:13 -07:00
params.c	…
pid.c	…
pid_namespace.c	…
posix-cpu-timers.c	…
posix-timers.c	…
printk.c	printk: Fix calculation of length used to discard records	2012-08-12 21:25:50 +03:00
profile.c	…
ptrace.c	…
range.c	…
rcu.h	…
rcupdate.c	…
rcutiny.c	…
rcutiny_plugin.h	…
rcutorture.c	…
rcutree.c	…
rcutree.h	…
rcutree_plugin.h	…
rcutree_trace.c	…
relay.c	…
res_counter.c	…
resource.c	resource: make sure requested range is included in the root range	2012-07-30 17:25:21 -07:00
rtmutex-debug.c	…
rtmutex-debug.h	…
rtmutex-tester.c	…
rtmutex.c	…
rtmutex.h	…
rtmutex_common.h	…
rwsem.c	…
seccomp.c	…
semaphore.c	…
signal.c	signal: make sure we don't get stopped with pending task_work	2012-07-22 23:57:54 +04:00
smp.c	…
smpboot.c	…
smpboot.h	…
softirq.c	mm: allow PF_MEMALLOC from softirq context	2012-07-31 18:42:45 -07:00
spinlock.c	…
srcu.c	…
stacktrace.c	…
stop_machine.c	…
sys.c	kernel/sys.c: avoid argv_free(NULL)	2012-07-30 17:25:13 -07:00
sys_ni.c	…
sysctl.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2012-08-01 10:26:23 -07:00
sysctl_binary.c	mm: prepare for removal of obsolete /proc/sys/vm/nr_pdflush_threads	2012-07-31 18:42:40 -07:00
task_work.c	task_work: add a scheduling point in task_work_run()	2012-08-21 09:11:44 -07:00
taskstats.c	taskstats: check nla_reserve() return	2012-07-30 17:25:21 -07:00
test_kprobes.c	…
time.c	…
timeconst.pl	…
timer.c	alpha: take a bunch of syscalls into osf_sys.c	2012-08-19 08:41:19 -07:00
tracepoint.c	…
tsacct.c	…
uid16.c	…
up.c	…
user-return-notifier.c	…
user.c	…
user_namespace.c	…
utsname.c	…
utsname_sysctl.c	…
wait.c	…
watchdog.c	Revert "NMI watchdog: fix for lockup detector breakage on resume"	2012-08-08 20:49:45 +02:00
workqueue.c	workqueue: fix possible idle worker depletion across CPU hotplug	2012-09-10 10:05:54 -07:00
workqueue_sched.h	…