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 openrisc. Signed-off-by: Mohd. Faris <[email protected]> Signed-off-by: Kautuk Consul <[email protected]> --- arch/openrisc/mm/fault.c | 32 ++++++++++++++++++++++++++------ 1 files changed, 26 insertions(+), 6 deletions(-) diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c index a5dce82..40f850e 100644 --- a/arch/openrisc/mm/fault.c +++ b/arch/openrisc/mm/fault.c @@ -54,6 +54,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, struct vm_area_struct *vma; siginfo_t info; int fault; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; tsk = current; @@ -105,6 +106,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, if (in_interrupt() || !mm) goto no_context; +retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -143,6 +145,7 @@ good_area: if (write_acc) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { /* not present */ if (!(vma->vm_flags & (VM_READ | VM_EXEC))) @@ -159,7 +162,11 @@ good_area: * the fault. */ - fault = handle_mm_fault(mm, vma, address, write_acc); + 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; @@ -167,11 +174,24 @@ good_area: goto do_sigbus; BUG(); } - /*RGD modeled on Cris */ - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; + + if (flags & FAULT_FLAG_ALLOW_RETRY) { + /*RGD modeled on Cris */ + if (fault & VM_FAULT_MAJOR) + 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); return; -- 1.7.5.4 _______________________________________________ Linux mailing list [email protected] http://lists.openrisc.net/listinfo/linux
