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| author | Kautuk Consul <consul.kautuk@gmail.com> | 2012-07-30 23:39:21 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-31 02:25:11 +0200 |
| commit | f107701f011e681a21b95259f950bf9c836884e0 (patch) | |
| tree | 9d84473e8d20396f1c08dd21fd168d9a4f9ccc09 /arch/xtensa | |
| parent | coredump: warn about unsafe suid_dumpable / core_pattern combo (diff) | |
| download | linux-f107701f011e681a21b95259f950bf9c836884e0.tar.xz linux-f107701f011e681a21b95259f950bf9c836884e0.zip | |
xtensa/mm/fault.c: port OOM changes to do_page_fault
Commits d065bd810b6d ("mm: retry page fault when blocking on disk
transfer") and 37b23e0525d3 ("x86,mm: make pagefault killable")
introduced changes into the x86 pagefault handler for making the page
fault handler retryable as well as killable.
These changes reduce the mmap_sem hold time, which is crucial during OOM
killer invocation.
Port these changes to xtensa.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Acked-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/xtensa')
| -rw-r--r-- | arch/xtensa/mm/fault.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c index b17885a0b508..5a74c53bc69c 100644 --- a/arch/xtensa/mm/fault.c +++ b/arch/xtensa/mm/fault.c @@ -44,6 +44,7 @@ void do_page_fault(struct pt_regs *regs) int is_write, is_exec; int fault; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; info.si_code = SEGV_MAPERR; @@ -71,6 +72,7 @@ void do_page_fault(struct pt_regs *regs) address, exccause, regs->pc, is_write? "w":"", is_exec? "x":""); #endif +retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -93,6 +95,7 @@ good_area: if (is_write) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else if (is_exec) { if (!(vma->vm_flags & VM_EXEC)) goto bad_area; @@ -104,7 +107,11 @@ good_area: * make sure we exit gracefully rather than endlessly redo * the fault. */ - fault = handle_mm_fault(mm, vma, address, is_write ? FAULT_FLAG_WRITE : 0); + fault = handle_mm_fault(mm, vma, address, flags); + + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return; + if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; @@ -112,10 +119,22 @@ good_area: goto do_sigbus; BUG(); } - if (fault & VM_FAULT_MAJOR) - current->maj_flt++; - else - current->min_flt++; + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) + current->maj_flt++; + else + current->min_flt++; + if (fault & VM_FAULT_RETRY) { + flags &= ~FAULT_FLAG_ALLOW_RETRY; + + /* No need to up_read(&mm->mmap_sem) as we would + * have already released it in __lock_page_or_retry + * in mm/filemap.c. + */ + + goto retry; + } + } up_read(&mm->mmap_sem); return; |