From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759678Ab2CaMGL (ORCPT ); Sat, 31 Mar 2012 08:06:11 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:46047 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759547Ab2CaMGJ (ORCPT ); Sat, 31 Mar 2012 08:06:09 -0400 From: Kautuk Consul To: Chris Metcalf , , Lucas De Marchi , Josh Triplett Cc: linux-kernel@vger.kernel.org, Kautuk Consul Subject: [PATCH 15/19 v2] tile/mm/fault.c: Port OOM changes to handle_page_fault Date: Sat, 31 Mar 2012 08:05:39 -0400 Message-Id: <1333195539-5421-1-git-send-email-consul.kautuk@gmail.com> X-Mailer: git-send-email 1.7.5.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 tile. Signed-off-by: Kautuk Consul --- arch/tile/mm/fault.c | 30 +++++++++++++++++++++++++----- 1 files changed, 25 insertions(+), 5 deletions(-) diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c index cba30e9..bba4cd9 100644 --- a/arch/tile/mm/fault.c +++ b/arch/tile/mm/fault.c @@ -266,6 +266,8 @@ static int handle_page_fault(struct pt_regs *regs, int si_code; int is_kernel_mode; pgd_t *pgd; + unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | + (write ? FAULT_FLAG_WRITE : 0)); /* on TILE, protection faults are always writes */ if (!is_page_fault) @@ -372,6 +374,8 @@ static int handle_page_fault(struct pt_regs *regs, vma = NULL; /* happy compiler */ goto bad_area_nosemaphore; } + +retry: down_read(&mm->mmap_sem); } @@ -419,7 +423,11 @@ good_area: * make sure we exit gracefully rather than endlessly redo * the fault. */ - fault = handle_mm_fault(mm, vma, address, write); + fault = handle_mm_fault(mm, vma, address, flags); + + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return 0; + if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; @@ -427,10 +435,22 @@ good_area: goto do_sigbus; BUG(); } - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; + if (flags & FAULT_FLAG_ALLOW_RETRY) { + 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; + } + } #if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC() /* -- 1.7.5.4