From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id C52F56B007E for ; Tue, 5 Oct 2010 03:54:01 -0400 (EDT) Received: from wpaz17.hot.corp.google.com (wpaz17.hot.corp.google.com [172.24.198.81]) by smtp-out.google.com with ESMTP id o957rtqh029797 for ; Tue, 5 Oct 2010 00:53:55 -0700 Received: from pxi17 (pxi17.prod.google.com [10.243.27.17]) by wpaz17.hot.corp.google.com with ESMTP id o957rrh6000616 for ; Tue, 5 Oct 2010 00:53:53 -0700 Received: by pxi17 with SMTP id 17so1814065pxi.29 for ; Tue, 05 Oct 2010 00:53:53 -0700 (PDT) From: Michel Lespinasse Subject: [PATCH 0/3] V2: Reduce mmap_sem hold times during file backed page faults Date: Tue, 5 Oct 2010 00:53:32 -0700 Message-Id: <1286265215-9025-1-git-send-email-walken@google.com> Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org, Linus Torvalds , Ying Han Cc: linux-kernel@vger.kernel.org, Andrew Morton , Rik van Riel , Nick Piggin , Peter Zijlstra List-ID: This is the second iteration of our change dropping mmap_sem when a disk access occurs during a page fault to a file backed VMA. Changes since V1: - Cleaned up 'Retry page fault when blocking on disk transfer' applying linus's suggestions - Added 'access_error API cleanup' Tests: - microbenchmark: thread A mmaps a large file and does random read accesses to the mmaped area - achieves about 55 iterations/s. Thread B does mmap/munmap in a loop at a separate location - achieves 55 iterations/s before, 15000 iterations/s after. - We are seeing related effects in some applications in house, which show significant performance regressions when running without this change. - I am looking for a microbenchmark to expose the worst case overhead of the page fault retry. Would FIO be a good match for that use ? Michel Lespinasse (3): filemap_fault: unique path for locking page Retry page fault when blocking on disk transfer. access_error API cleanup arch/x86/mm/fault.c | 44 +++++++++++++++++++++++++++++--------------- include/linux/mm.h | 2 ++ mm/filemap.c | 41 ++++++++++++++++++++++++++++++++--------- mm/memory.c | 3 ++- 4 files changed, 65 insertions(+), 25 deletions(-) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org