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authorKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>2011-05-26 17:12:12 +0900
committerIngo Molnar <mingo@elte.hu>2011-05-26 13:54:03 +0200
commitb80ef10e84d85a06bcd0b3a24a752ec32d0e0e40 (patch)
tree39a1d5b97203b99ab736f1b804a7782d6b3a05a5 /arch
parentde66ee979d0ea45171cc2501750e9f9f22f5a690 (diff)
downloadop-kernel-dev-b80ef10e84d85a06bcd0b3a24a752ec32d0e0e40.zip
op-kernel-dev-b80ef10e84d85a06bcd0b3a24a752ec32d0e0e40.tar.gz
x86: Move do_page_fault()'s error path under unlikely()
Ingo suggested SIGKILL check should be moved into slowpath function. This will reduce the page fault fastpath impact of this recent commit: 37b23e0525d3: x86,mm: make pagefault killable Suggested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: kamezawa.hiroyu@jp.fujitsu.com Cc: minchan.kim@gmail.com Cc: willy@linux.intel.com Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/4DDE0B5C.9050907@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/mm/fault.c35
1 files changed, 20 insertions, 15 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index f7a2a05..2dbf6bf 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -823,16 +823,30 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
force_sig_info_fault(SIGBUS, code, address, tsk, fault);
}
-static noinline void
+static noinline int
mm_fault_error(struct pt_regs *regs, unsigned long error_code,
unsigned long address, unsigned int fault)
{
+ /*
+ * Pagefault was interrupted by SIGKILL. We have no reason to
+ * continue pagefault.
+ */
+ if (fatal_signal_pending(current)) {
+ if (!(fault & VM_FAULT_RETRY))
+ up_read(&current->mm->mmap_sem);
+ if (!(error_code & PF_USER))
+ no_context(regs, error_code, address);
+ return 1;
+ }
+ if (!(fault & VM_FAULT_ERROR))
+ return 0;
+
if (fault & VM_FAULT_OOM) {
/* Kernel mode? Handle exceptions or die: */
if (!(error_code & PF_USER)) {
up_read(&current->mm->mmap_sem);
no_context(regs, error_code, address);
- return;
+ return 1;
}
out_of_memory(regs, error_code, address);
@@ -843,6 +857,7 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
else
BUG();
}
+ return 1;
}
static int spurious_fault_check(unsigned long error_code, pte_t *pte)
@@ -1133,19 +1148,9 @@ good_area:
*/
fault = handle_mm_fault(mm, vma, address, flags);
- if (unlikely(fault & VM_FAULT_ERROR)) {
- mm_fault_error(regs, error_code, address, fault);
- return;
- }
-
- /*
- * Pagefault was interrupted by SIGKILL. We have no reason to
- * continue pagefault.
- */
- if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
- if (!(error_code & PF_USER))
- no_context(regs, error_code, address);
- return;
+ if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) {
+ if (mm_fault_error(regs, error_code, address, fault))
+ return;
}
/*
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