diff options
| author | Kautuk Consul <consul.kautuk@gmail.com> | 2012-12-12 15:36:39 +0000 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2012-12-12 15:46:15 +0000 |
| commit | 3d7b6a674e266999a90ff1e21c6c839e30200c51 (patch) | |
| tree | 5c89370be6ffe8e328e5f28cf2877ce7580a37b3 | |
| parent | 83c2dc15ce824450e7044b9f90cd529c25747ae0 (diff) | |
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>
| -rw-r--r-- | arch/mn10300/mm/fault.c | 33 |
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; |