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| author | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2013-03-23 09:36:36 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-04-25 20:25:37 +0100 |
| commit | 04de139ab01f8a7e1e2d28f27cb28054d64985f5 (patch) | |
| tree | 7800d058d6671792e647ade79689a0a867ee21e6 /arch/cris/boot | |
| parent | 5bb757c000c7801614470079687473c39e666c87 (diff) | |
| download | lwn-04de139ab01f8a7e1e2d28f27cb28054d64985f5.tar.gz lwn-04de139ab01f8a7e1e2d28f27cb28054d64985f5.zip | |
x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal
commit 511ba86e1d386f671084b5d0e6f110bb30b8eeb2 upstream.
Invoking arch_flush_lazy_mmu_mode() results in calls to
preempt_enable()/disable() which may have performance impact.
Since lazy MMU is not used on bare metal we can patch away
arch_flush_lazy_mmu_mode() so that it is never called in such
environment.
[ hpa: the previous patch "Fix vmalloc_fault oops during lazy MMU
updates" may cause a minor performance regression on
bare metal. This patch resolves that performance regression. It is
somewhat unclear to me if this is a good -stable candidate. ]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1364045796-10720-2-git-send-email-konrad.wilk@oracle.com
Tested-by: Josh Boyer <jwboyer@redhat.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/cris/boot')
0 files changed, 0 insertions, 0 deletions