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authorKautuk Consul <consul.kautuk@gmail.com>2012-03-20 14:26:53 +0100
committerHelge Deller <deller@gmx.de>2013-02-20 22:51:31 +0100
commit38057477b98712bd9c735bf9d26b83c25d9d3279 (patch)
tree681dc06615614aa94605404a58e31620d856e3ca
parentparisc: space register variables need to be in native length (unsigned long) (diff)
downloadlinux-38057477b98712bd9c735bf9d26b83c25d9d3279.tar.xz
linux-38057477b98712bd9c735bf9d26b83c25d9d3279.zip
parisc/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 parisc. Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de>
-rw-r--r--arch/parisc/mm/fault.c30
1 files changed, 25 insertions, 5 deletions
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index 18162ce4261e..f247a3480e8e 100644
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -175,10 +175,12 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
struct mm_struct *mm = tsk->mm;
unsigned long acc_type;
int fault;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
if (in_atomic() || !mm)
goto no_context;
+retry:
down_read(&mm->mmap_sem);
vma = find_vma_prev(mm, address, &prev_vma);
if (!vma || address < vma->vm_start)
@@ -201,7 +203,12 @@ good_area:
* fault.
*/
- fault = handle_mm_fault(mm, vma, address, (acc_type & VM_WRITE) ? FAULT_FLAG_WRITE : 0);
+ fault = handle_mm_fault(mm, vma, address,
+ flags | ((acc_type & VM_WRITE) ? FAULT_FLAG_WRITE : 0));
+
+ if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+ return;
+
if (unlikely(fault & VM_FAULT_ERROR)) {
/*
* We hit a shared mapping outside of the file, or some
@@ -214,10 +221,23 @@ good_area:
goto bad_area;
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;