sparc/mm/fault_32.c: Port OOM changes to do_sparc_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 32-bit sparc.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Kautuk Consul 2012-03-26 06:47:54 +00:00 committed by David S. Miller
parent 7358e51082
commit c29554f53e

View file

@ -225,6 +225,8 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
unsigned long g2;
int from_user = !(regs->psr & PSR_PS);
int fault, code;
unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
(write ? FAULT_FLAG_WRITE : 0));
if(text_fault)
address = regs->pc;
@ -251,6 +253,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
down_read(&mm->mmap_sem);
/*
@ -289,7 +292,11 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
fault = handle_mm_fault(mm, vma, address, 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;
@ -297,13 +304,29 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
goto do_sigbus;
BUG();
}
if (flags & FAULT_FLAG_ALLOW_RETRY) {
if (fault & VM_FAULT_MAJOR) {
current->maj_flt++;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, address);
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
1, regs, address);
} else {
current->min_flt++;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, address);
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
1, regs, address);
}
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;