From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755122AbZFHN36 (ORCPT ); Mon, 8 Jun 2009 09:29:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753069AbZFHN3v (ORCPT ); Mon, 8 Jun 2009 09:29:51 -0400 Received: from gir.skynet.ie ([193.1.99.77]:56815 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752754AbZFHN3u (ORCPT ); Mon, 8 Jun 2009 09:29:50 -0400 Date: Mon, 8 Jun 2009 14:29:50 +0100 From: Mel Gorman To: Rik van Riel , Pekka Enberg , Andrew Morton Cc: Linux Kernel Mailing List , linux-mm Subject: [PATCH] Add a gfp-translate script to help understand page allocation failure reports Message-ID: <20090608132950.GB15070@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The page allocation failure messages include a line that looks like page allocation failure. order:1, mode:0x4020 The mode is easy to translate but irritating for the lazy and a bit error prone. This patch adds a very simple helper script gfp-translate for the mode: portion of the page allocation failure messages. An example usage looks like mel@machina:~/linux-2.6 $ scripts/gfp-translate 0x4020 Source: /home/mel/linux-2.6 Parsing: 0x4020 #define __GFP_HIGH (0x20) /* Should access emergency pools? */ #define __GFP_COMP (0x4000) /* Add compound page metadata */ The script is not a work of art but it has come in handy for me a few times so I thought I would share. Signed-off-by: Mel Gorman --- scripts/gfp-translate | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/scripts/gfp-translate b/scripts/gfp-translate new file mode 100755 index 0000000..724db2d --- /dev/null +++ b/scripts/gfp-translate @@ -0,0 +1,81 @@ +#!/bin/bash +# Translate the bits making up a GFP mask +# (c) 2009, Mel Gorman +# Licensed under the terms of the GNU GPL License version 2 +SOURCE= +GFPMASK=none + +# Helper function to report failures and exit +die() { + echo ERROR: $@ + if [ "$TMPFILE" != "" ]; then + rm -f $TMPFILE + fi + exit -1 +} + +usage() { + echo "usage: gfp-translate [-h] [ --source DIRECTORY ] gfpmask" + exit 0 +} + +# Parse command-line arguements +while [ $# -gt 0 ]; do + case $1 in + --source) + SOURCE=$2 + shift 2 + ;; + -h) + usage + ;; + --help) + usage + ;; + *) + GFPMASK=$1 + shift + ;; + esac +done + +# Guess the kernel source directory if it's not set. Preference is in order of +# o current directory +# o /usr/src/linux +if [ "$SOURCE" = "" ]; then + if [ -r "/usr/src/linux/Makefile" ]; then + SOURCE=/usr/src/linux + fi + if [ -r "`pwd`/Makefile" ]; then + SOURCE=`pwd` + fi +fi + +# Confirm that a source directory exists +if [ ! -r "$SOURCE/Makefile" ]; then + die "Could not locate source directory or it is invalid" +fi + +# Confirm that a GFP mask has been specified +if [ "$GFPMASK" = "none" ]; then + usage +fi + +# Extract GFP flags from the kernel source +TMPFILE=`mktemp -t gfptranslate-XXXXXX` || exit 1 +grep "^#define __GFP" $SOURCE/include/linux/gfp.h | sed -e 's/(__force gfp_t)//' | sed -e 's/u)/)/' | grep -v GFP_BITS | sed -e 's/)\//) \//' > $TMPFILE + +# Parse the flags +IFS=" +" +echo Source: $SOURCE +echo Parsing: $GFPMASK +for LINE in `cat $TMPFILE`; do + MASK=`echo $LINE | awk '{print $3}'` + if [ $(($GFPMASK&$MASK)) -ne 0 ]; then + echo $LINE + fi +done + +rm -f $TMPFILE +exit 0