Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4971f2bd authored by Kautuk Consul's avatar Kautuk Consul Committed by Jonas Bonn
Browse files

openrisc/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 openrisc.

Signed-off-by: default avatarMohd. Faris <mohdfarisq2010@gmail.com>
Signed-off-by: default avatarKautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: default avatarJonas Bonn <jonas@southpole.se>
parent ad188f95

arch/openrisc/mm/fault.c

+26 −6
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, 
	struct vm_area_struct *vma;

	siginfo_t info;

	int fault;

	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;



	tsk = current;
@@ -105,6 +106,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, 
	if (in_interrupt() || !mm)

		goto no_context;



retry:

	down_read(&mm->mmap_sem);

	vma = find_vma(mm, address);
@@ -143,6 +145,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, 
	if (write_acc) {

		if (!(vma->vm_flags & VM_WRITE))

			goto bad_area;

		flags |= FAULT_FLAG_WRITE;

	} else {

		/* not present */

		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
@@ -159,7 +162,11 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, 
	 * the fault.

	 */



	fault = handle_mm_fault(mm, vma, address, write_acc);

	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;
@@ -167,11 +174,24 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, 
			goto do_sigbus;

		BUG();

	}



	if (flags & FAULT_FLAG_ALLOW_RETRY) {

		/*RGD modeled on Cris */

		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;