https://github.com/torvalds/linux
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

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
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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
builtin-buildid-list.c
/*
 * builtin-buildid-list.c
 *
 * Builtin buildid-list command: list buildids in perf.data
 *
 * Copyright (C) 2009, Red Hat Inc.
 * Copyright (C) 2009, Arnaldo Carvalho de Melo <acme@redhat.com>
 */
#include "builtin.h"
#include "perf.h"
#include "util/build-id.h"
#include "util/cache.h"
#include "util/debug.h"
#include "util/parse-options.h"
#include "util/session.h"
#include "util/symbol.h"

static char const *input_name = "perf.data";
static bool force;
static bool with_hits;

static const char * const buildid_list_usage[] = {
	"perf buildid-list [<options>]",
	NULL
};

static const struct option options[] = {
	OPT_BOOLEAN('H', "with-hits", &with_hits, "Show only DSOs with hits"),
	OPT_STRING('i', "input", &input_name, "file",
		    "input file name"),
	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
	OPT_INCR('v', "verbose", &verbose,
		    "be more verbose"),
	OPT_END()
};

static int __cmd_buildid_list(void)
{
	int err = -1;
	struct perf_session *session;

	session = perf_session__new(input_name, O_RDONLY, force, false);
	if (session == NULL)
		return -1;

	if (with_hits)
		perf_session__process_events(session, &build_id__mark_dso_hit_ops);

	perf_session__fprintf_dsos_buildid(session, stdout, with_hits);

	perf_session__delete(session);
	return err;
}

int cmd_buildid_list(int argc, const char **argv, const char *prefix __used)
{
	argc = parse_options(argc, argv, options, buildid_list_usage, 0);
	setup_pager();
	return __cmd_buildid_list();
}
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