Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753586Ab0DZGu7 (ORCPT ); Mon, 26 Apr 2010 02:50:59 -0400 Received: from mga10.intel.com ([192.55.52.92]:17974 "EHLO fmsmga102.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751834Ab0DZGu5 (ORCPT ); Mon, 26 Apr 2010 02:50:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.52,272,1270450800"; d="scan'208";a="792718607" Subject: Re: [PATCH] perf: limit memory allocation to number cpus online From: "Zhang, Yanmin" To: Tony Jones Cc: Ingo Molnar , LKML In-Reply-To: <20100330220823.GA16876@suse.de> References: <20100330220823.GA16876@suse.de> Content-Type: text/plain; charset="ISO-8859-1" Date: Mon, 26 Apr 2010 14:51:15 +0800 Message-Id: <1272264675.2078.639.camel@ymzhang.sh.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.28.0 (2.28.0-2.fc12) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4474 Lines: 125 On Tue, 2010-03-30 at 15:08 -0700, Tony Jones wrote: > Subject: perf: limit memory allocation to number cpus online > From: Tony Jones > Date: Tue, 30 Mar 2010 12:18:08 -0700 > > Limit the dynamic allocation of fd, event_array and mmap_array to #cpus online > rather than MAX_NR_CPUS. Acked. Sorry for replying late. There will be a much more valuable patch if it fixes the cpu hotplug issue. For example, if my machine starts 16 cpu and I hot unplug some of them by software method (i.e. echo 0 >/sys/devices/system/cpu/cpuXXX/online) after kernel boots, perf will fail when collecting a system-wide statistics. That's because sys_perf_event_open fails on removed cpu. > > Cc: Zhang Yanmin > Signed-off-by: Tony Jones > --- > tools/perf/builtin-record.c | 10 +++++++--- > tools/perf/builtin-stat.c | 4 ++-- > tools/perf/builtin-top.c | 14 +++++++------- > 3 files changed, 16 insertions(+), 12 deletions(-) > > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index 60ecdd3..25b5536 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -560,7 +560,6 @@ static int __cmd_record(int argc, const char **argv) > if ((!system_wide && !inherit) || profile_cpu != -1) { > open_counters(profile_cpu); > } else { > - nr_cpus = read_cpu_map(); > for (i = 0; i < nr_cpus; i++) > open_counters(cpumap[i]); > } > @@ -748,7 +747,12 @@ int cmd_record(int argc, const char **argv, const char *prefix __used) > thread_num = 1; > } > > - for (i = 0; i < MAX_NR_CPUS; i++) { > + if (system_wide && profile_cpu == -1) > + nr_cpus = read_cpu_map(); > + else > + nr_cpus = 1; > + > + for (i = 0; i < nr_cpus; i++) { > for (j = 0; j < MAX_COUNTERS; j++) { > fd[i][j] = malloc(sizeof(int)*thread_num); > mmap_array[i][j] = zalloc( > @@ -758,7 +762,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used) > } > } > event_array = malloc( > - sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num); > + sizeof(struct pollfd)*nr_cpus*MAX_COUNTERS*thread_num); > if (!event_array) > return -ENOMEM; > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index 1036ca7..d9b672e 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -540,7 +540,7 @@ static const struct option options[] = { > int cmd_stat(int argc, const char **argv, const char *prefix __used) > { > int status; > - int i,j; > + unsigned int i,j; > > argc = parse_options(argc, argv, options, stat_usage, > PARSE_OPT_STOP_AT_NON_OPTION); > @@ -577,7 +577,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used) > thread_num = 1; > } > > - for (i = 0; i < MAX_NR_CPUS; i++) { > + for (i = 0; i < nr_cpus; i++) { > for (j = 0; j < MAX_COUNTERS; j++) { > fd[i][j] = malloc(sizeof(int)*thread_num); > if (!fd[i][j]) > diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c > index 4abdd9b..f05d270 100644 > --- a/tools/perf/builtin-top.c > +++ b/tools/perf/builtin-top.c > @@ -1368,7 +1368,12 @@ int cmd_top(int argc, const char **argv, const char *prefix __used) > thread_num = 1; > } > > - for (i = 0; i < MAX_NR_CPUS; i++) { > + if (target_tid != -1 || profile_cpu != -1) > + nr_cpus = 1; > + else > + nr_cpus = read_cpu_map(); > + > + for (i = 0; i < nr_cpus; i++) { > for (j = 0; j < MAX_COUNTERS; j++) { > fd[i][j] = malloc(sizeof(int)*thread_num); > mmap_array[i][j] = zalloc( > @@ -1378,7 +1383,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used) > } > } > event_array = malloc( > - sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num); > + sizeof(struct pollfd)*nr_cpus*MAX_COUNTERS*thread_num); > if (!event_array) > return -ENOMEM; > > @@ -1424,11 +1429,6 @@ int cmd_top(int argc, const char **argv, const char *prefix __used) > attrs[counter].sample_period = default_interval; > } > > - if (target_tid != -1 || profile_cpu != -1) > - nr_cpus = 1; > - else > - nr_cpus = read_cpu_map(); > - > get_term_dimensions(&winsize); > if (print_entries == 0) { > update_print_entries(&winsize); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/