* [PATCH 13/20] cris/mm/fault.c: Port OOM changes to do_page_fault
@ 2012-03-20 13:24 Kautuk Consul
2012-03-21 15:16 ` Jesper Nilsson
0 siblings, 1 reply; 2+ messages in thread
From: Kautuk Consul @ 2012-03-20 13:24 UTC (permalink / raw)
To: Mikael Starvik, Jesper Nilsson
Cc: linux-cris-kernel, linux-kernel, Kautuk Consul
Commit d065bd810b6deb67d4897a14bfe21f8eb526ba99
(mm: retry page fault when blocking on disk transfer) and
commit 37b23e0525d393d48a7d59f870b3bc061a30ccdb
(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: Kautuk Consul <consul.kautuk@gmail.com>
---
arch/cris/mm/fault.c | 31 ++++++++++++++++++++++++++-----
1 files changed, 26 insertions(+), 5 deletions(-)
diff --git a/arch/cris/mm/fault.c b/arch/cris/mm/fault.c
index 9dcac8e..384890d 100644
--- a/arch/cris/mm/fault.c
+++ b/arch/cris/mm/fault.c
@@ -57,6 +57,8 @@ 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",
@@ -114,6 +116,7 @@ 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)
@@ -162,7 +165,11 @@ 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;
@@ -170,10 +177,24 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
goto do_sigbus;
BUG();
}
- if (fault & VM_FAULT_MAJOR)
- tsk->maj_flt++;
- else
- tsk->min_flt++;
+
+ 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;
--
1.7.5.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH 13/20] cris/mm/fault.c: Port OOM changes to do_page_fault
2012-03-20 13:24 [PATCH 13/20] cris/mm/fault.c: Port OOM changes to do_page_fault Kautuk Consul
@ 2012-03-21 15:16 ` Jesper Nilsson
0 siblings, 0 replies; 2+ messages in thread
From: Jesper Nilsson @ 2012-03-21 15:16 UTC (permalink / raw)
To: Kautuk Consul; +Cc: Mikael Starvik, linux-cris-kernel, linux-kernel
On Tue, Mar 20, 2012 at 02:24:05PM +0100, Kautuk Consul wrote:
> Commit d065bd810b6deb67d4897a14bfe21f8eb526ba99
> (mm: retry page fault when blocking on disk transfer) and
> commit 37b23e0525d393d48a7d59f870b3bc061a30ccdb
> (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.
Looks good!
> Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
/^JN - Jesper Nilsson
--
Jesper Nilsson -- jesper.nilsson@axis.com
^ permalink raw reply [flat|nested] 2+ messages in thread
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