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authorKautuk Consul <consul.kautuk@gmail.com>2012-12-12 15:36:39 +0000
committerDavid Howells <dhowells@redhat.com>2012-12-12 15:46:15 +0000
commit3d7b6a674e266999a90ff1e21c6c839e30200c51 (patch)
tree5c89370be6ffe8e328e5f28cf2877ce7580a37b3 /arch/mn10300/mm
parent83c2dc15ce824450e7044b9f90cd529c25747ae0 (diff)
downloadlinux-3d7b6a674e266999a90ff1e21c6c839e30200c51.tar.gz
mn10300/mm/fault.c: Port OOM changes to do_page_fault
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 mn10300. Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'arch/mn10300/mm')
-rw-r--r--arch/mn10300/mm/fault.c33
1 files changed, 25 insertions, 8 deletions
diff --git a/arch/mn10300/mm/fault.c b/arch/mn10300/mm/fault.c
index 90f346f7392..d48a84fd7fa 100644
--- a/arch/mn10300/mm/fault.c
+++ b/arch/mn10300/mm/fault.c
@@ -123,7 +123,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long fault_code,
struct mm_struct *mm;
unsigned long page;
siginfo_t info;
- int write, fault;
+ int fault;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
#ifdef CONFIG_GDBSTUB
/* handle GDB stub causing a fault */
@@ -170,6 +171,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long fault_code,
if (in_atomic() || !mm)
goto no_context;
+retry:
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
@@ -220,7 +222,6 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long fault_code,
*/
good_area:
info.si_code = SEGV_ACCERR;
- write = 0;
switch (fault_code & (MMUFCR_xFC_PGINVAL|MMUFCR_xFC_TYPE)) {
default: /* 3: write, present */
case MMUFCR_xFC_TYPE_WRITE:
@@ -232,7 +233,7 @@ good_area:
case MMUFCR_xFC_PGINVAL | MMUFCR_xFC_TYPE_WRITE:
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
- write++;
+ flags |= FAULT_FLAG_WRITE;
break;
/* read from protected page */
@@ -251,7 +252,11 @@ good_area:
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
- fault = handle_mm_fault(mm, vma, address, write ? 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;
@@ -259,10 +264,22 @@ good_area:
goto do_sigbus;
BUG();
}
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (fault & VM_FAULT_MAJOR)
+ current->maj_flt++;
+ else
+ current->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;