Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

avr32/mm/fault.c: port OOM changes to do_page_fault

Browse source 
Commits d065bd810b ("mm: retry page fault when blocking on disk
transfer") and 37b23e0525 ("x86,mm: make pagefault killable")
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 AVR32.

[akpm@linux-foundation.org: fix comment layout]
Signed-off-by: Mohd. Faris <mohdfarisq2010@gmail.com>
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kautuk Consul 2012-07-30 14:39:25 -07:00 • committed by Linus Torvalds
parent 7eafef6d1d
commit bf7c27e988
1 changed files with 25 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

33
arch/avr32/mm/fault.c
View file

@ -61,10 +61,10 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
const struct exception_table_entry *fixup; const struct exception_table_entry *fixup;
unsigned long address; unsigned long address;
unsigned long page; unsigned long page;
int writeaccess;
long signr; long signr;
int code; int code;
int fault; int fault;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
if (notify_page_fault(regs, ecr)) if (notify_page_fault(regs, ecr))
return; return;
@ -86,6 +86,7 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
local_irq_enable(); local_irq_enable();
retry:
down_read(&mm->mmap_sem); down_read(&mm->mmap_sem);
vma = find_vma(mm, address); vma = find_vma(mm, address);
@ -104,7 +105,6 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
*/ */
good_area: good_area:
code = SEGV_ACCERR; code = SEGV_ACCERR;
writeaccess = 0;
switch (ecr) { switch (ecr) {
case ECR_PROTECTION_X: case ECR_PROTECTION_X:
@ -121,7 +121,7 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
case ECR_TLB_MISS_W: case ECR_TLB_MISS_W:
if (!(vma->vm_flags & VM_WRITE)) if (!(vma->vm_flags & VM_WRITE))
goto bad_area; goto bad_area;
writeaccess = 1; flags |= FAULT_FLAG_WRITE;
break; break;
default: default:
panic("Unhandled case %lu in do_page_fault!", ecr); panic("Unhandled case %lu in do_page_fault!", ecr);
@ -132,7 +132,11 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
* sure we exit gracefully rather than endlessly redo the * sure we exit gracefully rather than endlessly redo the
* fault. * fault.
*/ */
fault = handle_mm_fault(mm, vma, address, writeaccess ? 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 (unlikely(fault & VM_FAULT_ERROR)) {
if (fault & VM_FAULT_OOM) if (fault & VM_FAULT_OOM)
goto out_of_memory; goto out_of_memory;
@ -140,10 +144,23 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
goto do_sigbus; goto do_sigbus;
BUG(); BUG();
} }
if (fault & VM_FAULT_MAJOR)
tsk->maj_flt++; if (flags & FAULT_FLAG_ALLOW_RETRY) {
else if (fault & VM_FAULT_MAJOR)
tsk->min_flt++; 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); up_read(&mm->mmap_sem);
return; return;