hexagon/mm/vm_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 hexagon.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: Richard Kuo <rkuo@codeaurora.org>
This commit is contained in:
Kautuk Consul 2012-03-20 09:23:33 -04:00 committed by Richard Kuo
parent 222c547ee7
commit 393a86af71

View File

@ -53,6 +53,8 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
int si_code = SEGV_MAPERR; int si_code = SEGV_MAPERR;
int fault; int fault;
const struct exception_table_entry *fixup; const struct exception_table_entry *fixup;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
(cause > 0 ? FAULT_FLAG_WRITE : 0);
/* /*
* If we're in an interrupt or have no user context, * If we're in an interrupt or have no user context,
@ -63,6 +65,7 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
local_irq_enable(); local_irq_enable();
retry:
down_read(&mm->mmap_sem); down_read(&mm->mmap_sem);
vma = find_vma(mm, address); vma = find_vma(mm, address);
if (!vma) if (!vma)
@ -96,14 +99,23 @@ good_area:
break; break;
} }
fault = handle_mm_fault(mm, vma, address, (cause > 0)); fault = handle_mm_fault(mm, vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
return;
/* The most common case -- we are done. */ /* The most common case -- we are done. */
if (likely(!(fault & VM_FAULT_ERROR))) { if (likely(!(fault & VM_FAULT_ERROR))) {
if (fault & VM_FAULT_MAJOR) if (flags & FAULT_FLAG_ALLOW_RETRY) {
current->maj_flt++; if (fault & VM_FAULT_MAJOR)
else current->maj_flt++;
current->min_flt++; else
current->min_flt++;
if (fault & VM_FAULT_RETRY) {
flags &= ~FAULT_FLAG_ALLOW_RETRY;
goto retry;
}
}
up_read(&mm->mmap_sem); up_read(&mm->mmap_sem);
return; return;