Revision 2a6e06b2aed6995af401dcd4feb5e79a0c7ea554 authored by Linus Torvalds on 17 March 2013, 22:44:43 UTC, committed by Linus Torvalds on 17 March 2013, 22:44:43 UTC
Commit 1d9d8639c063 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") fixed a crash when doing PEBS performance profiling
after resuming, but in using init_debug_store_on_cpu() to restore the
DS_AREA mtrr it also resulted in a new WARN_ON() triggering.

init_debug_store_on_cpu() uses "wrmsr_on_cpu()", which in turn uses CPU
cross-calls to do the MSR update.  Which is not really valid at the
early resume stage, and the warning is quite reasonable.  Now, it all
happens to _work_, for the simple reason that smp_call_function_single()
ends up just doing the call directly on the CPU when the CPU number
matches, but we really should just do the wrmsr() directly instead.

This duplicates the wrmsr() logic, but hopefully we can just remove the
wrmsr_on_cpu() version eventually.

Reported-and-tested-by: Parag Warudkar <parag.lkml@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 0863702
Raw File
numastat.txt

Numa policy hit/miss statistics

/sys/devices/system/node/node*/numastat

All units are pages. Hugepages have separate counters.

numa_hit	A process wanted to allocate memory from this node,
		and succeeded.

numa_miss	A process wanted to allocate memory from another node,
		but ended up with memory from this node.

numa_foreign	A process wanted to allocate on this node,
		but ended up with memory from another one.

local_node	A process ran on this node and got memory from it.

other_node	A process ran on this node and got memory from another node.

interleave_hit 	Interleaving wanted to allocate from this node
		and succeeded.

For easier reading you can use the numastat utility from the numactl package
(http://oss.sgi.com/projects/libnuma/). Note that it only works
well right now on machines with a small number of CPUs.

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