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authorRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>2013-10-21 18:05:08 +0200
committerIngo Molnar <mingo@kernel.org>2013-10-26 12:23:22 +0200
commit4c4e4f61368164f326fe59e2156c70d7faa72c17 (patch)
tree3507a3abdf0622bb04503f07941b52d2088a3bd6 /arch/x86
parentlockstat: Report avg wait and hold times (diff)
downloadlinux-4c4e4f61368164f326fe59e2156c70d7faa72c17.tar.xz
linux-4c4e4f61368164f326fe59e2156c70d7faa72c17.zip
x86/locking/kconfig: Update paravirt spinlock Kconfig description
Since the paravirt spinlock optimizations went into the v3.12 kernel we have a very good performance benefit for paravirtualized KVM / Xen kernels. Also we no longer suffer from 5% side effect on native kernel that is mentioned in the Kconfig entry. So update the Kconfig entry accordingly. pvspinlock benefit on KVM link: https://lkml.org/lkml/2013/8/6/178 Attilio's tests on native kernel impact: http://blog.xen.org/index.php/2012/05/11/benchmarking-the-new-pv-ticketlock-implementation/ Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: <konrad.wilk@oracle.com> Cc: <linux@eikelenboom.it> Cc: <gleb@redhat.com> Cc: <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1382371508-3843-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com [ Updated the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/Kconfig6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ee2fb9d37745..a92572de2ac1 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -638,10 +638,10 @@ config PARAVIRT_SPINLOCKS
spinlock implementation with something virtualization-friendly
(for example, block the virtual CPU rather than spinning).
- Unfortunately the downside is an up to 5% performance hit on
- native kernels, with various workloads.
+ It has a minimal impact on native kernels and gives a nice performance
+ benefit on paravirtualized KVM / Xen kernels.
- If you are unsure how to answer this question, answer N.
+ If you are unsure how to answer this question, answer Y.
source "arch/x86/xen/Kconfig"