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authorJohannes Weiner <hannes@cmpxchg.org>2013-09-12 15:13:39 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-21 09:22:56 -0800
commite2ec2c2b96808afa2f57ec7d7949691146fca341 (patch)
tree9056b3be2fc19f9a00993a01507776a97b7d3ebd /arch/tile
parent086c6cc5377d0908667e8f7082633aebf45cf95f (diff)
arch: mm: pass userspace fault flag to generic fault handler
commit 759496ba6407c6994d6a5ce3a5e74937d7816208 upstream. Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/tile')
-rw-r--r--arch/tile/mm/fault.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index ac553eed6390..3ff289f422e6 100644
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -280,8 +280,7 @@ static int handle_page_fault(struct pt_regs *regs,
if (!is_page_fault)
write = 1;
- flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
- (write ? FAULT_FLAG_WRITE : 0));
+ flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
is_kernel_mode = (EX1_PL(regs->ex1) != USER_PL);
@@ -365,6 +364,9 @@ static int handle_page_fault(struct pt_regs *regs,
goto bad_area_nosemaphore;
}
+ if (!is_kernel_mode)
+ flags |= FAULT_FLAG_USER;
+
/*
* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the
@@ -425,6 +427,7 @@ good_area:
#endif
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
+ flags |= FAULT_FLAG_WRITE;
} else {
if (!is_page_fault || !(vma->vm_flags & VM_READ))
goto bad_area;