linux/include
Arjan van de Ven 69d25870f2 cpuidle: fix the menu governor to boost IO performance
Fix the menu idle governor which balances power savings, energy efficiency
and performance impact.

The reason for a reworked governor is that there have been serious
performance issues reported with the existing code on Nehalem server
systems.

To show this I'm sure Andrew wants to see benchmark results:
(benchmark is "fio", "no cstates" is using "idle=poll")

		no cstates	current linux	new algorithm
1 disk		107 Mb/s	85 Mb/s		105 Mb/s
2 disks		215 Mb/s	123 Mb/s	209 Mb/s
12 disks	590 Mb/s	320 Mb/s	585 Mb/s

In various power benchmark measurements, no degredation was found by our
measurement&diagnostics team.  Obviously a small percentage more power was
used in the "fio" benchmark, due to the much higher performance.

While it would be a novel idea to describe the new algorithm in this
commit message, I cheaped out and described it in comments in the code
instead.

[changes since first post: spelling fixes from akpm, review feedback,
folded menu-tng into menu.c]

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:45 -07:00
..
acpi includecheck fix: include/acpi, acpi_bus.h 2009-09-20 16:02:39 +05:30
asm-generic mm: add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions 2009-09-22 07:17:41 -07:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2009-09-11 09:38:37 -07:00
drm Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2009-09-21 08:10:09 -07:00
keys RxRPC: Use uX/sX rather than uintX_t/intX_t types 2009-09-16 00:01:13 -07:00
linux cpuidle: fix the menu governor to boost IO performance 2009-09-22 07:17:45 -07:00
math-emu
media V4L/DVB (13019): video: initial support for ADV7180 2009-09-19 00:53:39 -03:00
mtd
net pkt_sched: Fix tx queue selection in tc_modify_qdisc 2009-09-15 02:53:07 -07:00
pcmcia pcmcia: Use phys_addr_t for physical addresses 2009-09-15 10:17:15 -07:00
rdma
rxrpc
scsi [SCSI] libiscsi, bnx2i: make bound ep check common 2009-09-12 09:35:33 -05:00
sound Merge branch 'topic/ymfpci' into for-linus 2009-09-10 15:33:09 +02:00
trace tracing, page-allocator: add trace event for page traffic related to the buddy lists 2009-09-22 07:17:34 -07:00
video
xen
Kbuild