Dave Jones df8b59be09 [CPUFREQ] Avoid the ondemand cpufreq governor to use a too high frequency for stats. ... The problem is in the ondemand governor, there is a periodic measurement of the CPU usage. This CPU usage is updated by the scheduler after every tick (basically, by adding 1 either to "idle" or to "user" or to "system"). So if the frequency of the governor is too high, the stat will be meaningless (as mostly no number have changed). So this patch checks that the measurements are separated by at least 10 ticks. It means that by default, stats will have about 5% error (20 ticks). Of course those numbers can be argued but, IMHO, they look sane. The patch also includes a small clean-up to check more explictly the result of the conversion from ns to µs being null. Let's note that (on x86) this has never been really needed before 2.6.13 because HZ was always 1000. Now that HZ can be 100, some CPU might be affected by this problem. For instance when HZ=100, the centrino ,which has a 10µs transition latency, would lead to the governor allowing to read stats every tick (10ms)! Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net> Signed-off-by: Dave Jones <davej@redhat.com>		2005-09-20 12:39:35 -07:00
..
acorn	[PATCH] timer initialization cleanup: DEFINE_TIMER	2005-09-09 14:03:48 -07:00
acpi	[PATCH] remove ACPI S4bios support	2005-09-10 10:06:35 -07:00
atm	[PATCH] timer initialization cleanup: DEFINE_TIMER	2005-09-09 14:03:48 -07:00
base	[PATCH] drivers/base/*: use kzalloc instead of kmalloc+memset	2005-09-13 08:22:27 -07:00
block	[PATCH] fix pf request handling	2005-09-17 11:50:03 -07:00
bluetooth	[Bluetooth] Add ignore parameters to the HCI USB driver	2005-09-13 01:32:37 +02:00
cdrom	[PATCH] drivers/cdrom: fix-up schedule_timeout() usage	2005-09-10 10:06:38 -07:00
char	Merge branch 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6	2005-09-16 11:54:13 -07:00
connector	[NET]: Add netlink connector.	2005-09-11 19:15:07 -07:00
cpufreq	[CPUFREQ] Avoid the ondemand cpufreq governor to use a too high frequency for stats.	2005-09-20 12:39:35 -07:00
crypto	[CRYPTO] Update IV correctly for Padlock CBC encryption	2005-07-06 13:54:09 -07:00
dio	[PATCH] Driver Core: drivers/base - drivers/i2c/chips/adm1026.c: update device attribute callbacks	2005-06-20 15:15:32 -07:00
eisa	[PATCH] Driver Core: drivers/base - drivers/i2c/chips/adm1026.c: update device attribute callbacks	2005-06-20 15:15:32 -07:00
fc4	[SCSI] fc4 warning fix	2005-07-30 09:47:53 -05:00
firmware	[PATCH] dell_rbu tidy	2005-09-17 11:50:02 -07:00
hwmon	[PATCH] hdaps driver update	2005-09-17 11:50:02 -07:00
i2c	[I2C] Add a functionality method, and remove algorithm ids	2005-09-14 22:54:45 +01:00
ide	[PATCH] ide: fix null request pointer for taskfile ioctl	2005-09-17 11:50:03 -07:00
ieee1394	Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-for-linus-2.6	2005-09-12 20:02:18 -07:00
infiniband	Merge master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband	2005-09-11 10:16:07 -07:00
input	[PATCH] SharpSL: Add an input keyboard driver for Zaurus cxx00 series	2005-09-13 08:22:31 -07:00
isdn	[PATCH] Fix ST 5481 USB driver	2005-09-17 15:34:30 -07:00
macintosh	[PATCH] swsusp: switch pm_message_t to struct	2005-09-05 00:06:16 -07:00
mca	[PATCH] unexport mca_find_device_by_slot	2005-06-25 16:24:56 -07:00
md	[PATCH] RAID6 Altivec fix	2005-09-17 11:49:58 -07:00
media	[PATCH] v4l: fixup on cx88_dvb for Dvico HDTV5 Gold	2005-09-13 08:22:32 -07:00
message	[SCSI] fusion SAS support (mptsas driver) minor fix	2005-09-19 12:48:22 -05:00
mfd	[MFD] Cleanups suggested by Dmitri, Vojtech and lists.	2005-09-11 10:28:00 +01:00
misc	[PATCH] hdpu_cpustate.c: misc_register() can fail	2005-09-10 10:06:25 -07:00
mmc	[MMC] Clean up wbsd detection handling	2005-09-12 20:36:19 +01:00
mtd	[PATCH] MTD: Update SharpSL partition definitions	2005-09-17 11:49:58 -07:00
net	[WAN] hdlc_cisco: Fix regression introduced by skb->tail changes.	2005-09-19 15:39:32 -07:00
nubus	Linux-2.6.12-rc2	2005-04-16 15:20:36 -07:00
oprofile	[PATCH] clean up inline static vs static inline	2005-07-27 16:26:20 -07:00
parisc	[PATCH] merge some from Rusty's trivial patches	2005-09-10 10:06:30 -07:00
parport	[PATCH] parport: fix-up schedule_timeout() usage	2005-09-10 10:06:38 -07:00
pci	[PATCH] shpchp: Use dword accessors for PCI_ROM_ADDRESS	2005-09-17 11:50:03 -07:00
pcmcia	Fix yenta error message when unable to find a bus assignment	2005-09-14 13:05:17 -07:00
pnp	Merge linux-2.6 with linux-acpi-2.6	2005-09-08 01:45:47 -04:00
s390	Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-for-linus-2.6	2005-09-20 08:50:49 -07:00
sbus	[PATCH] Remove unnecessary check_region references in comments	2005-09-13 08:22:29 -07:00
scsi	Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-for-linus-2.6	2005-09-20 08:50:49 -07:00
serial	[PATCH] Fix up some pm_message_t types	2005-09-17 11:50:00 -07:00
sh	[PATCH] Driver Core: drivers/s390/net/qeth_sys.c - drivers/usb/gadget/pxa2xx_udc.c: update device attribute callbacks	2005-06-20 15:15:35 -07:00
sn	[PATCH] ioc4: PCI bus speed detection	2005-06-21 18:46:32 -07:00
tc	[PATCH] Remove unnecessary check_region references in comments	2005-09-13 08:22:29 -07:00
telephony	[PATCH] telephony: fix-up schedule_timeout() usage	2005-09-10 10:06:39 -07:00
usb	[PATCH] USB: ftdi_sio: custom baud rate fix	2005-09-12 12:23:54 -07:00
video	[PATCH] Fix up some pm_message_t types	2005-09-17 11:50:00 -07:00
w1	[PATCH] crc16: remove w1 specific comments.	2005-09-12 12:35:17 -07:00
zorro	[PATCH] Driver Core: drivers/usb/input/aiptek.c - drivers/zorro/zorro-sysfs.c: update device attribute callbacks	2005-06-20 15:15:35 -07:00
Kconfig	[NET]: Add netlink connector.	2005-09-11 19:15:07 -07:00
Makefile	[NET]: Add netlink connector.	2005-09-11 19:15:07 -07:00