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| author | Kautuk Consul <consul.kautuk@gmail.com> | 2012-07-30 14:39:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-30 17:25:11 -0700 |
| commit | bf7c27e9887af48952743753916f9cfbe900d0e9 (patch) | |
| tree | 500736901ab3cc72e7f90332602d1419897ae1f9 /arch/avr32 | |
| parent | 7eafef6d1d712aa9973c3cbd0013a5b66d5a6604 (diff) | |
| download | linux-bf7c27e9887af48952743753916f9cfbe900d0e9.tar.bz2 | |
avr32/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 AVR32.
[akpm@linux-foundation.org: fix comment layout]
Signed-off-by: Mohd. Faris <mohdfarisq2010@gmail.com>
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/avr32')
| -rw-r--r-- | arch/avr32/mm/fault.c | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c index f7040a1e399f..b92e60958617 100644 --- a/arch/avr32/mm/fault.c +++ b/arch/avr32/mm/fault.c @@ -61,10 +61,10 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs) const struct exception_table_entry *fixup; unsigned long address; unsigned long page; - int writeaccess; long signr; int code; int fault; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; if (notify_page_fault(regs, ecr)) return; @@ -86,6 +86,7 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs) local_irq_enable(); +retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -104,7 +105,6 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs) */ good_area: code = SEGV_ACCERR; - writeaccess = 0; switch (ecr) { case ECR_PROTECTION_X: @@ -121,7 +121,7 @@ good_area: case ECR_TLB_MISS_W: if (!(vma->vm_flags & VM_WRITE)) goto bad_area; - writeaccess = 1; + flags |= FAULT_FLAG_WRITE; break; default: panic("Unhandled case %lu in do_page_fault!", ecr); @@ -132,7 +132,11 @@ good_area: * sure we exit gracefully rather than endlessly redo the * fault. */ - fault = handle_mm_fault(mm, vma, address, writeaccess ? 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; @@ -140,10 +144,23 @@ good_area: goto do_sigbus; BUG(); } - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; + + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) + tsk->maj_flt++; + else + tsk->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; |