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avr32/mm/fault.c: port OOM changes to do_page_fault

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Commits d065bd810b ("mm: retry page fault when blocking on disk
transfer") and 37b23e0525 ("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>
This commit is contained in:
Kautuk Consul 2012-07-30 14:39:25 -07:00 committed by Linus Torvalds
parent 7eafef6d1d
commit bf7c27e988
1 changed files with 25 additions and 8 deletions
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33
arch/avr32/mm/fault.c
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@ -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 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
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 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
* 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 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
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;