mm: add a gfp-translate script to help understand page allocation failure reports (608e8e66) · Commits · 戴 / test

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. [akpm@linux-foundation.org: clarify an error message] Signed-off-by:

Mel Gorman <mel@csn.ul.ie> Acked-by:

Rik van Riel <riel@redhat.com> Acked-by:

Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Hellwig <hch@infradead.org> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

scripts/gfp-translate

0 → 100644

+81 −0

Original line number	Diff line number	Diff line
		#!/bin/bash
		# Translate the bits making up a GFP mask
		# (c) 2009, Mel Gorman <mel@csn.ul.ie>
		# 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 kernel 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

Admin message