linux/arch/x86/lguest
Boris Ostrovsky 511ba86e1d x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal
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>
Cc: <stable@vger.kernel.org> SEE NOTE ABOVE
2013-04-10 11:25:10 -07:00
..
Kconfig lguest: select CONFIG_TTY to build properly. 2013-02-14 16:01:55 -08:00
Makefile lguest: fix 'unhandled trap 13' with CONFIG_CC_STACKPROTECTOR 2009-06-04 11:50:06 -07:00
boot.c x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal 2013-04-10 11:25:10 -07:00
i386_head.S lguest: Fix three simple typos in comments 2011-07-22 14:39:50 +09:30