From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933684Ab2C3N3Z (ORCPT ); Fri, 30 Mar 2012 09:29:25 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:61203 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932077Ab2C3N3S (ORCPT ); Fri, 30 Mar 2012 09:29:18 -0400 Message-ID: <4F75B529.2070202@monstr.eu> Date: Fri, 30 Mar 2012 15:29:13 +0200 From: Michal Simek Reply-To: monstr@monstr.eu User-Agent: Mozilla/5.0 (X11; Linux i686; rv:10.0.3) Gecko/20120314 Thunderbird/10.0.3 MIME-Version: 1.0 To: Kautuk Consul CC: microblaze-uclinux@itee.uq.edu.au, linux-kernel@vger.kernel.org Subject: Re: [PATCH 07/20] microblaze/mm/fault.c: Port OOM changes to do_page_fault References: <1332249700-2781-1-git-send-email-consul.kautuk@gmail.com> In-Reply-To: <1332249700-2781-1-git-send-email-consul.kautuk@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/20/2012 02:21 PM, Kautuk Consul wrote: > 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 microblaze. > > Signed-off-by: Kautuk Consul > --- > arch/microblaze/mm/fault.c | 33 ++++++++++++++++++++++++++++----- > 1 files changed, 28 insertions(+), 5 deletions(-) > > diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c > index ae97d2c..60e19e6 100644 > --- a/arch/microblaze/mm/fault.c > +++ b/arch/microblaze/mm/fault.c > @@ -93,6 +93,8 @@ void do_page_fault(struct pt_regs *regs, unsigned long address, > int code = SEGV_MAPERR; > int is_write = error_code& ESR_S; > int fault; > + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | > + (is_write ? FAULT_FLAG_WRITE : 0); > > regs->ear = address; > regs->esr = error_code; > @@ -139,6 +141,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address, > if (kernel_mode(regs)&& !search_exception_tables(regs->pc)) > goto bad_area_nosemaphore; > > +retry: > down_read(&mm->mmap_sem); > } > > @@ -211,7 +214,11 @@ good_area: > * make sure we exit gracefully rather than endlessly redo > * the fault. > */ > - fault = handle_mm_fault(mm, vma, address, is_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; > @@ -219,11 +226,27 @@ good_area: > goto do_sigbus; > BUG(); > } > - if (unlikely(fault& VM_FAULT_MAJOR)) > - current->maj_flt++; > - else > - current->min_flt++; > + > + if (flags& FAULT_FLAG_ALLOW_RETRY) { > + if (unlikely(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); > + > /* > * keep track of tlb+htab misses that are good addrs but > * just need pte's created via handle_mm_fault() it is fine. Acked-by: Michal Simek If this patch should go through my tree, please let me know. Thanks, Michal -- Michal Simek, Ing. (M.Eng) w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/ Microblaze U-BOOT custodian