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linux-stable/arch/powerpc/kernel/vdso64
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Anton Blanchard 18ad51dd34 powerpc: Add VDSO version of getcpu 
We have a request for a fast method of getting CPU and NUMA node IDs
from userspace. This patch implements a getcpu VDSO function,
similar to x86.

Ben suggested we use SPRG3 which is userspace readable. SPRG3 can be
modified by a KVM guest, so we save the SPRG3 value in the paca and
restore it when transitioning from the guest to the host.

I have a glibc patch that implements sched_getcpu on top of this.
Testing on a POWER7:

baseline: 538 cycles
vdso:      30 cycles

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-11 14:18:40 +10:00
..
.gitignore
cacheflush.S [POWERPC] vdso: Fixes for cache block sizes 2007-11-20 13:56:31 +11:00
datapage.S
getcpu.S powerpc: Add VDSO version of getcpu 2012-07-11 14:18:40 +10:00
gettimeofday.S powerpc: Rework VDSO gettimeofday to prevent time going backwards 2010-07-09 11:26:16 +10:00
Makefile powerpc: Add VDSO version of getcpu 2012-07-11 14:18:40 +10:00
note.S
sigtramp.S Fix common misspellings 2011-03-31 11:26:23 -03:00
vdso64.lds.S powerpc: Add VDSO version of getcpu 2012-07-11 14:18:40 +10:00
vdso64_wrapper.S Use macros for .data.page_aligned section. 2009-09-21 06:27:08 +02:00