diff options
| author | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2013-03-23 09:36:36 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-04-16 21:27:27 -0700 |
| commit | 7ad0908564a3554f9b13258a7927411af62bf3bc (patch) | |
| tree | 6d0c0ebded4a05e03751638cff10e5a41d1cf86e /arch/x86/lguest | |
| parent | e082a177477ef0221076a201236a20c8f51c0090 (diff) | |
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/lguest')
| -rw-r--r-- | arch/x86/lguest/boot.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 642d8805bc1..53272bd9675 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -1333,6 +1333,7 @@ __init void lguest_init(void) pv_mmu_ops.read_cr3 = lguest_read_cr3; pv_mmu_ops.lazy_mode.enter = paravirt_enter_lazy_mmu; pv_mmu_ops.lazy_mode.leave = lguest_leave_lazy_mmu_mode; + pv_mmu_ops.lazy_mode.flush = paravirt_flush_lazy_mmu; pv_mmu_ops.pte_update = lguest_pte_update; pv_mmu_ops.pte_update_defer = lguest_pte_update; |