Dave Hansen 3cd49fd7da perf: Drop sample rate when sampling is too slow ... commit 14c63f17b1 upstream. This patch keeps track of how long perf's NMI handler is taking, and also calculates how many samples perf can take a second. If the sample length times the expected max number of samples exceeds a configurable threshold, it drops the sample rate. This way, we don't have a runaway sampling process eating up the CPU. This patch can tend to drop the sample rate down to level where perf doesn't work very well. *BUT* the alternative is that my system hangs because it spends all of its time handling NMIs. I'll take a busted performance tool over an entire system that's busted and undebuggable any day. BTW, my suspicion is that there's still an underlying bug here. Using the HPET instead of the TSC is definitely a contributing factor, but I suspect there are some other things going on. But, I can't go dig down on a bug like that with my machine hanging all the time. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: acme@ghostprotocols.net Cc: Dave Hansen <dave@sr71.net> [ Prettified it a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Weng Meiling <wengmeiling.weng@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2014-06-11 12:03:26 -07:00
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acpi	ACPI / hotplug: Fix conflicted PCI bridge notify handlers	2013-12-04 10:57:04 -08:00
asm-generic	mm: use paravirt friendly ops for NUMA hinting ptes	2014-05-30 21:52:12 -07:00
clocksource	clocksource: arch_timer: use virtual counters	2014-01-09 12:24:26 -08:00
crypto	crypto: scatterwalk - Use sg_chain_ptr on chain entries	2013-12-11 22:36:29 -08:00
drm	drm/radeon: 0x9649 is SUMO2 not SUMO	2014-01-09 12:24:22 -08:00
dt-bindings
keys
linux	perf: Drop sample rate when sampling is too slow	2014-06-11 12:03:26 -07:00
math-emu
media	media: v4l2: added missing mutex.h include to v4l2-ctrls.h	2013-09-26 17:18:26 -07:00
memory
misc
net	net: sctp: cache auth_enable per endpoint	2014-05-30 21:52:15 -07:00
pcmcia
ras
rdma
rxrpc
scsi	scsi: fix our current target reap infrastructure	2014-05-30 21:52:11 -07:00
sound	ALSA: memalloc.h - fix wrong truncation of dma_addr_t	2013-12-20 07:45:06 -08:00
target	iscsi/iser-target: Fix isert_conn->state hung shutdown issues	2014-03-23 21:38:21 -07:00
trace	trace: module: Maintain a valid user count	2014-06-07 13:25:35 -07:00
uapi	USB: cdc-wdm: properly include types.h	2014-06-11 12:03:25 -07:00
video	Merge branch 'fbdev-3.10-fixes' of git://gitorious.org/linux-omap-dss2/linux into linux-fbdev/for-3.10-fixes	2013-05-29 17:00:34 +08:00
xen	xenbus: delay xenbus frontend resume if xenstored is not running	2013-05-29 09:04:19 -04:00
Kbuild	UAPI: remove empty Kbuild files	2013-04-30 17:04:09 -07:00