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27 March 2024, 02:37:15 UTC
Revision 2dc91abe03d8ce6dd7f9251faffafca5f6b9e85d authored by Nick Piggin on 17 August 2010, 18:37:37 UTC, committed by Al Viro on 18 August 2010, 12:35:48 UTC 
lglock: introduce special lglock and brlock spin locks
 
lglock: introduce special lglock and brlock spin locks

This patch introduces "local-global" locks (lglocks). These can be used to:

- Provide fast exclusive access to per-CPU data, with exclusive access to
  another CPU's data allowed but possibly subject to contention, and to provide
  very slow exclusive access to all per-CPU data.
- Or to provide very fast and scalable read serialisation, and to provide
  very slow exclusive serialisation of data (not necessarily per-CPU data).

Brlocks are also implemented as a short-hand notation for the latter use
case.

Thanks to Paul for local/global naming convention.

Cc: linux-kernel@vger.kernel.org
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1 parent d996b62
Raw File
Tip revision: 2dc91abe03d8ce6dd7f9251faffafca5f6b9e85d authored by Nick Piggin on 17 August 2010, 18:37:37 UTC
lglock: introduce special lglock and brlock spin locks
Tip revision: 2dc91ab
perf-archive.sh 
#!/bin/bash
# perf archive
# Arnaldo Carvalho de Melo <acme@redhat.com>

PERF_DATA=perf.data
if [ $# -ne 0 ] ; then
	PERF_DATA=$1
fi

#
# PERF_BUILDID_DIR environment variable set by perf
# path to buildid directory, default to $HOME/.debug
#
if [ -z $PERF_BUILDID_DIR ]; then
	PERF_BUILDID_DIR=~/.debug/
else
        # append / to make substitutions work
        PERF_BUILDID_DIR=$PERF_BUILDID_DIR/
fi

BUILDIDS=$(mktemp /tmp/perf-archive-buildids.XXXXXX)
NOBUILDID=0000000000000000000000000000000000000000

perf buildid-list -i $PERF_DATA --with-hits | grep -v "^$NOBUILDID " > $BUILDIDS
if [ ! -s $BUILDIDS ] ; then
	echo "perf archive: no build-ids found"
	rm -f $BUILDIDS
	exit 1
fi

MANIFEST=$(mktemp /tmp/perf-archive-manifest.XXXXXX)

cut -d ' ' -f 1 $BUILDIDS | \
while read build_id ; do
	linkname=$PERF_BUILDID_DIR.build-id/${build_id:0:2}/${build_id:2}
	filename=$(readlink -f $linkname)
	echo ${linkname#$PERF_BUILDID_DIR} >> $MANIFEST
	echo ${filename#$PERF_BUILDID_DIR} >> $MANIFEST
done

tar cfj $PERF_DATA.tar.bz2 -C $PERF_BUILDID_DIR -T $MANIFEST
rm -f $MANIFEST $BUILDIDS
echo -e "Now please run:\n"
echo -e "$ tar xvf $PERF_DATA.tar.bz2 -C ~/.debug\n"
echo "wherever you need to run 'perf report' on."
exit 0
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