From 38057477b98712bd9c735bf9d26b83c25d9d3279 Mon Sep 17 00:00:00 2001 From: Kautuk Consul Date: Tue, 20 Mar 2012 09:26:53 -0400 Subject: 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 Signed-off-by: Helge Deller --- arch/parisc/mm/fault.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) (limited to 'arch') 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; -- cgit v1.2.3