Venkatesh Pallipadi 49c6f4a2ba sched: Fix softirq time accounting ... Commit: 75e1056f5c upstream Peter Zijlstra found a bug in the way softirq time is accounted in VIRT_CPU_ACCOUNTING on this thread: http://lkml.indiana.edu/hypermail//linux/kernel/1009.2/01366.html The problem is, softirq processing uses local_bh_disable internally. There is no way, later in the flow, to differentiate between whether softirq is being processed or is it just that bh has been disabled. So, a hardirq when bh is disabled results in time being wrongly accounted as softirq. Looking at the code a bit more, the problem exists in !VIRT_CPU_ACCOUNTING as well. As account_system_time() in normal tick based accouting also uses softirq_count, which will be set even when not in softirq with bh disabled. Peter also suggested solution of using 2*SOFTIRQ_OFFSET as irq count for local_bh_{disable,enable} and using just SOFTIRQ_OFFSET while softirq processing. The patch below does that and adds API in_serving_softirq() which returns whether we are currently processing softirq or not. Also changes one of the usages of softirq_count in net/sched/cls_cgroup.c to in_serving_softirq. Looks like many usages of in_softirq really want in_serving_softirq. Those changes can be made individually on a case by case basis. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-2-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>		2011-02-17 15:37:24 -08:00
..
acpi	ACPI: skip checking BM_STS if the BIOS doesn't ask for it	2010-08-02 10:21:24 -07:00
asm-generic	dma-mapping: fix dma_sync_single_range_*	2010-05-26 14:29:14 -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	drm/radeon: remove 0x4243 pci id	2011-02-17 15:37:16 -08:00
keys	RxRPC: Use uX/sX rather than uintX_t/intX_t types	2009-09-16 00:01:13 -07:00
linux	sched: Fix softirq time accounting	2011-02-17 15:37:24 -08:00
math-emu	math-emu: correct test for downshifting fraction in _FP_FROM_INT()	2010-08-02 10:20:44 -07:00
media	V4L/DVB (13019): video: initial support for ADV7180	2009-09-19 00:53:39 -03:00
mtd
net	sctp: Fix a race between ICMP protocol unreachable and connect()	2011-01-07 14:43:18 -08:00
pcmcia	PM / yenta: Split resume into early and late parts (rev. 4)	2009-11-03 10:54:58 +01:00
rdma	trivial: fix typo "to to" in multiple files	2009-09-21 15:14:55 +02:00
rxrpc
scsi	SCSI: fc-transport: Use packed modifier for fc_bsg_request structure.	2010-04-26 07:41:30 -07:00
sound	ALSA: emu10k1 - delay the PCM interrupts (add pcm_irq_delay parameter)	2010-08-26 16:41:34 -07:00
trace	tracing: Fix ftrace_event_call alignment for use with gcc 4.5	2010-05-12 14:57:14 -07:00
video	davinci-fb-frame-buffer-driver-for-ti-da8xx-omap-l1xx-v4	2009-09-23 07:39:51 -07:00
xen
Kbuild