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parisc/mm/fault.c: Port OOM changes to do_page_fault 

Commit d065bd810b
(mm: retry page fault when blocking on disk transfer) and
commit 37b23e0525
(x86,mm: make pagefault killable)

The above commits 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 parisc.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Kautuk Consul 2012-03-20 09:26:53 -04:00 committed by Helge Deller
parent 45b6eff2a6
commit 38057477b9
1 changed files with 25 additions and 5 deletions
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30
arch/parisc/mm/fault.c
View File

@ -175,10 +175,12 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
struct mm_struct *mm = tsk->mm;
unsigned long acc_type;
int fault;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
if (in_atomic() || !mm)
goto no_context;
retry:
down_read(&mm->mmap_sem);
vma = find_vma_prev(mm, address, &prev_vma);
if (!vma || address < vma->vm_start)
@ -201,7 +203,12 @@ good_area:
* fault.
*/
fault = handle_mm_fault(mm, vma, address, (acc_type & VM_WRITE) ? FAULT_FLAG_WRITE : 0);
fault = handle_mm_fault(mm, vma, address,
flags | ((acc_type & VM_WRITE) ? FAULT_FLAG_WRITE : 0));
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {
/*
* We hit a shared mapping outside of the file, or some
@ -214,10 +221,23 @@ good_area:
goto bad_area;
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;