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Commit 4d5914d6 authored by Kautuk Consul's avatar Kautuk Consul Committed by Jesper Nilsson
Browse files

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



Commit d065bd81
(mm: retry page fault when blocking on disk transfer) and
commit 37b23e05
(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 CRIS.

Signed-off-by: default avatarKautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: default avatarJesper Nilsson <jesper.nilsson@axis.com>
parent dfb73a07

arch/cris/mm/fault.c

+26 −5
Original line number Diff line number Diff line
@@ -58,6 +58,8 @@ do_page_fault(unsigned long address, struct pt_regs *regs, 
	struct vm_area_struct * vma;

	siginfo_t info;

	int fault;

	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |

				((writeaccess & 1) ? FAULT_FLAG_WRITE : 0);



	D(printk(KERN_DEBUG

		 "Page fault for %lX on %X at %lX, prot %d write %d\n",
@@ -115,6 +117,7 @@ do_page_fault(unsigned long address, struct pt_regs *regs, 
	if (in_atomic() || !mm)

		goto no_context;



retry:

	down_read(&mm->mmap_sem);

	vma = find_vma(mm, address);

	if (!vma)
@@ -163,7 +166,11 @@ do_page_fault(unsigned long address, struct pt_regs *regs, 
	 * the fault.

	 */



	fault = handle_mm_fault(mm, vma, address, (writeaccess & 1) ? 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;
@@ -171,10 +178,24 @@ do_page_fault(unsigned long address, struct pt_regs *regs, 
			goto do_sigbus;

		BUG();

	}



	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;