From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41251 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745AbbJRAvm (ORCPT ); Sat, 17 Oct 2015 20:51:42 -0400 Subject: Patch "arm64: readahead: fault retry breaks mmap file read random detection" has been added to the 3.10-stable tree To: salyzyn@android.com, fengguang.wu@intel.com, gregkh@linuxfoundation.org, riandrews@android.com, riel@redhat.com, shli@kernel.org, will.deacon@arm.com Cc: , From: Date: Sat, 17 Oct 2015 17:51:42 -0700 Message-ID: <1445129502135227@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled arm64: readahead: fault retry breaks mmap file read random detection to the 3.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-readahead-fault-retry-breaks-mmap-file-read-random-detection.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 569ba74a7ba69f46ce2950bf085b37fea2408385 Mon Sep 17 00:00:00 2001 From: Mark Salyzyn Date: Mon, 21 Sep 2015 21:39:50 +0100 Subject: arm64: readahead: fault retry breaks mmap file read random detection From: Mark Salyzyn commit 569ba74a7ba69f46ce2950bf085b37fea2408385 upstream. This is the arm64 portion of commit 45cac65b0fcd ("readahead: fault retry breaks mmap file read random detection"), which was absent from the initial port and has since gone unnoticed. The original commit says: > .fault now can retry. The retry can break state machine of .fault. In > filemap_fault, if page is miss, ra->mmap_miss is increased. In the second > try, since the page is in page cache now, ra->mmap_miss is decreased. And > these are done in one fault, so we can't detect random mmap file access. > > Add a new flag to indicate .fault is tried once. In the second try, skip > ra->mmap_miss decreasing. The filemap_fault state machine is ok with it. With this change, Mark reports that: > Random read improves by 250%, sequential read improves by 40%, and > random write by 400% to an eMMC device with dm crypto wrapped around it. Cc: Shaohua Li Cc: Rik van Riel Cc: Wu Fengguang Signed-off-by: Mark Salyzyn Signed-off-by: Riley Andrews Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/fault.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -278,6 +278,7 @@ retry: * starvation. */ mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; + mm_flags |= FAULT_FLAG_TRIED; goto retry; } } Patches currently in stable-queue which might be from salyzyn@android.com are queue-3.10/arm64-readahead-fault-retry-breaks-mmap-file-read-random-detection.patch