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| author | Johannes Weiner <hannes@cmpxchg.org> | 2013-09-12 15:13:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-12 15:38:01 -0700 |
| commit | 759496ba6407c6994d6a5ce3a5e74937d7816208 (patch) | |
| tree | aeff8de8af36f70f2591114cef58c9ae7df25565 /arch/x86/mm | |
| parent | 871341023c771ad233620b7a1fb3d9c7031c4e5c (diff) | |
| download | blackbird-op-linux-759496ba6407c6994d6a5ce3a5e74937d7816208.tar.gz blackbird-op-linux-759496ba6407c6994d6a5ce3a5e74937d7816208.zip | |
arch: mm: pass userspace fault flag to generic fault handler
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: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/fault.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 654be4ae3047..6d77c3866faa 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1011,9 +1011,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) unsigned long address; struct mm_struct *mm; int fault; - int write = error_code & PF_WRITE; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; tsk = current; mm = tsk->mm; @@ -1083,6 +1081,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) if (user_mode_vm(regs)) { local_irq_enable(); error_code |= PF_USER; + flags |= FAULT_FLAG_USER; } else { if (regs->flags & X86_EFLAGS_IF) local_irq_enable(); @@ -1109,6 +1108,9 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) return; } + if (error_code & PF_WRITE) + flags |= FAULT_FLAG_WRITE; + /* * When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in |
