From 393a86af71b5bc6b11eac8e1594fb8be4c2ce84c Mon Sep 17 00:00:00 2001 From: Kautuk Consul Date: Tue, 20 Mar 2012 09:23:33 -0400 Subject: [PATCH] hexagon/mm/vm_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 hexagon. Signed-off-by: Kautuk Consul Signed-off-by: Richard Kuo --- arch/hexagon/mm/vm_fault.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c index c10b76ff9d65..06695cc4fe58 100644 --- a/arch/hexagon/mm/vm_fault.c +++ b/arch/hexagon/mm/vm_fault.c @@ -53,6 +53,8 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs) int si_code = SEGV_MAPERR; int fault; const struct exception_table_entry *fixup; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | + (cause > 0 ? FAULT_FLAG_WRITE : 0); /* * If we're in an interrupt or have no user context, @@ -63,6 +65,7 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs) local_irq_enable(); +retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); if (!vma) @@ -96,14 +99,23 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs) break; } - fault = handle_mm_fault(mm, vma, address, (cause > 0)); + fault = handle_mm_fault(mm, vma, address, flags); + + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return; /* The most common case -- we are done. */ if (likely(!(fault & VM_FAULT_ERROR))) { - 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; + goto retry; + } + } up_read(&mm->mmap_sem); return;