diff options
| author | Kautuk Consul <consul.kautuk@gmail.com> | 2012-03-31 08:06:11 -0400 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2012-04-11 12:37:54 +0900 |
| commit | 11fd982400a8779cb4b5f7cdc806008569ff545c (patch) | |
| tree | c87061068b9dc94ae4bdecb760ec005fd182fd09 | |
| parent | bbb4ce50f3169b08764f9965fd5b9655646d545a (diff) | |
sh/mm/fault_32.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 the 32-bit SH platform.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
| -rw-r--r-- | arch/sh/mm/fault_32.c | 38 |
1 files changed, 29 insertions, 9 deletions
diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c index 324eef93c90..98e88a6112b 100644 --- a/arch/sh/mm/fault_32.c +++ b/arch/sh/mm/fault_32.c @@ -129,6 +129,8 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, int si_code; int fault; siginfo_t info; + unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | + (writeaccess ? FAULT_FLAG_WRITE : 0)); tsk = current; mm = tsk->mm; @@ -169,6 +171,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, if (in_atomic() || !mm) goto no_context; +retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -200,7 +203,11 @@ good_area: * make sure we exit gracefully rather than endlessly redo * the 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 (fault & VM_FAULT_OOM) goto out_of_memory; @@ -208,14 +215,27 @@ good_area: goto do_sigbus; BUG(); } - if (fault & VM_FAULT_MAJOR) { - tsk->maj_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, - regs, address); - } else { - tsk->min_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, - regs, address); + + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) { + tsk->maj_flt++; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, + regs, address); + } else { + tsk->min_flt++; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, + regs, address); + } + 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); |