From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757821Ab0JEHx5 (ORCPT ); Tue, 5 Oct 2010 03:53:57 -0400 Received: from smtp-out.google.com ([216.239.44.51]:29628 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755360Ab0JEHx4 (ORCPT ); Tue, 5 Oct 2010 03:53:56 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=from:to:cc:subject:date:message-id:x-mailer; b=HgmZYTqR4u/fuavRtszE41ifWCuB/RRot0uEcBSfcqtfZM0eDZiAht472x5umzt+MN LBZjie98uHt569VK003A== From: Michel Lespinasse To: linux-mm@kvack.org, Linus Torvalds , Ying Han Cc: linux-kernel@vger.kernel.org, Andrew Morton , Rik van Riel , Nick Piggin , Peter Zijlstra 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> X-Mailer: git-send-email 1.7.1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(-)