Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758142Ab1DNRBk (ORCPT ); Thu, 14 Apr 2011 13:01:40 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:52978 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752181Ab1DNRBi (ORCPT ); Thu, 14 Apr 2011 13:01:38 -0400 Date: Thu, 14 Apr 2011 14:01:21 -0300 From: Arnaldo Carvalho de Melo To: Peter Zijlstra Cc: mingo@redhat.com, hpa@zytor.com, paulus@samba.org, eranian@google.com, linux-kernel@vger.kernel.org, tzanussi@gmail.com, efault@gmx.de, fweisbec@gmail.com, dsahern@gmail.com, tglx@linutronix.de, mingo@elte.hu, linux-tip-commits@vger.kernel.org Subject: Re: [tip:perf/core] perf evsel: Fix inverted test for fixing up attr.inherit flag Message-ID: <20110414170121.GC3229@ghostprotocols.net> References:

<1302357942.9086.1281.camel@twins> <20110411173536.GA29895@ghostprotocols.net> <1302796046.2035.28.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1302796046.2035.28.camel@laptop> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.19 (2009-01-05) X-SRS-Rewrite: SMTP reverse-path rewritten from by canuck.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 14349 Lines: 374 Em Thu, Apr 14, 2011 at 05:47:26PM +0200, Peter Zijlstra escreveu: > On Mon, 2011-04-11 at 14:35 -0300, Arnaldo Carvalho de Melo wrote: > > > > Can you check if the patch below fixes this? An acked-by or tested-by > > tag would be mucho appreciated. > > > > Didn't work.. > > # ./perf stat ~/loop_1b_instructions-4x > > Performance counter stats for '/root/loop_1b_instructions-4x': > > 288.908743 task-clock-msecs # 0.444 CPUs > 51 context-switches # 0.000 M/sec > 1 CPU-migrations # 0.000 M/sec > 116 page-faults # 0.000 M/sec > 715,288,186 cycles # 2475.827 M/sec (scaled from 49.77%) > 1,000,703,570 instructions # 1.399 IPC (scaled from 64.61%) > 100,255,005 branches # 347.013 M/sec (scaled from 56.19%) > 11,453 branch-misses # 0.011 % (scaled from 65.27%) > 26,089 cache-references # 0.090 M/sec (scaled from 43.82%) > 110 cache-misses # 0.000 M/sec (scaled from 36.35%) > > 0.649991199 seconds time elapsed > > That wants to have 4b insn There was another, sillier problem, now seems to work, ack? [acme@emilia linux]$ perf stat ~/loop_1b_instructions-4x Performance counter stats for '/home/acme/loop_1b_instructions-4x': 1451.781634 task-clock-msecs # 3.965 CPUs 1,463 context-switches # 0.001 M/sec 3 CPU-migrations # 0.000 M/sec 187 page-faults # 0.000 M/sec 2,865,021,951 cycles # 1973.452 M/sec (scaled from 70.29%) 4,001,127,146 instructions # 1.397 IPC (scaled from 80.24%) 401,476,915 branches # 276.541 M/sec (scaled from 80.27%) 63,800 branch-misses # 0.016 % (scaled from 80.29%) 262,866 cache-references # 0.181 M/sec (scaled from 20.14%) 10,938 cache-misses # 0.008 M/sec (scaled from 20.07%) 0.366184692 seconds time elapsed [acme@emilia linux]$ >From 41d8ff6c4be9216cae74dd82381d9f486e82bf22 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 14 Apr 2011 11:20:14 -0300 Subject: [PATCH] perf evsel: Fix use of inherit perf stat doesn't mmap and its perfectly fine for it to use task-bound counters with inheritance. So set the attr.inherit on the caller and leave the syscall itself to validate it. When the mmap fails perf_evlist__mmap will just emit a warning if this is the failure reason. Reported-by: Peter Zijlstra Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Tom Zanussi Link: http://lkml.kernel.org/n/tip-c9vd0a96jgm7nltt5cala44x@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 7 +++++-- tools/perf/builtin-stat.c | 7 ++++--- tools/perf/builtin-test.c | 10 +++++----- tools/perf/builtin-top.c | 3 ++- tools/perf/util/evlist.c | 14 ++++++++++---- tools/perf/util/evsel.c | 27 +++++++-------------------- tools/perf/util/evsel.h | 6 +++--- tools/perf/util/python.c | 9 +++++---- 8 files changed, 41 insertions(+), 42 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 17d1dcb..4165382 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -163,6 +163,7 @@ static void config_attr(struct perf_evsel *evsel, struct perf_evlist *evlist) struct perf_event_attr *attr = &evsel->attr; int track = !evsel->idx; /* only the first counter needs these */ + attr->inherit = !no_inherit; attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING | PERF_FORMAT_ID; @@ -251,6 +252,9 @@ static void open_counters(struct perf_evlist *evlist) { struct perf_evsel *pos; + if (evlist->cpus->map[0] < 0) + no_inherit = true; + list_for_each_entry(pos, &evlist->entries, node) { struct perf_event_attr *attr = &pos->attr; /* @@ -271,8 +275,7 @@ static void open_counters(struct perf_evlist *evlist) retry_sample_id: attr->sample_id_all = sample_id_all_avail ? 1 : 0; try_again: - if (perf_evsel__open(pos, evlist->cpus, evlist->threads, group, - !no_inherit) < 0) { + if (perf_evsel__open(pos, evlist->cpus, evlist->threads, group) < 0) { int err = errno; if (err == EPERM || err == EACCES) { diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index e2109f9..03f0e45 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -167,16 +167,17 @@ static int create_perf_stat_counter(struct perf_evsel *evsel) attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING; + attr->inherit = !no_inherit; + if (system_wide) - return perf_evsel__open_per_cpu(evsel, evsel_list->cpus, false, false); + return perf_evsel__open_per_cpu(evsel, evsel_list->cpus, false); - attr->inherit = !no_inherit; if (target_pid == -1 && target_tid == -1) { attr->disabled = 1; attr->enable_on_exec = 1; } - return perf_evsel__open_per_thread(evsel, evsel_list->threads, false, false); + return perf_evsel__open_per_thread(evsel, evsel_list->threads, false); } /* diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c index 1b2106c..11e3c84 100644 --- a/tools/perf/builtin-test.c +++ b/tools/perf/builtin-test.c @@ -290,7 +290,7 @@ static int test__open_syscall_event(void) goto out_thread_map_delete; } - if (perf_evsel__open_per_thread(evsel, threads, false, false) < 0) { + if (perf_evsel__open_per_thread(evsel, threads, false) < 0) { pr_debug("failed to open counter: %s, " "tweak /proc/sys/kernel/perf_event_paranoid?\n", strerror(errno)); @@ -303,7 +303,7 @@ static int test__open_syscall_event(void) } if (perf_evsel__read_on_cpu(evsel, 0, 0) < 0) { - pr_debug("perf_evsel__open_read_on_cpu\n"); + pr_debug("perf_evsel__read_on_cpu\n"); goto out_close_fd; } @@ -365,7 +365,7 @@ static int test__open_syscall_event_on_all_cpus(void) goto out_thread_map_delete; } - if (perf_evsel__open(evsel, cpus, threads, false, false) < 0) { + if (perf_evsel__open(evsel, cpus, threads, false) < 0) { pr_debug("failed to open counter: %s, " "tweak /proc/sys/kernel/perf_event_paranoid?\n", strerror(errno)); @@ -418,7 +418,7 @@ static int test__open_syscall_event_on_all_cpus(void) continue; if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) { - pr_debug("perf_evsel__open_read_on_cpu\n"); + pr_debug("perf_evsel__read_on_cpu\n"); err = -1; break; } @@ -529,7 +529,7 @@ static int test__basic_mmap(void) perf_evlist__add(evlist, evsels[i]); - if (perf_evsel__open(evsels[i], cpus, threads, false, false) < 0) { + if (perf_evsel__open(evsels[i], cpus, threads, false) < 0) { pr_debug("failed to open counter: %s, " "tweak /proc/sys/kernel/perf_event_paranoid?\n", strerror(errno)); diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index fc1273e..7e3d6e3 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -845,9 +845,10 @@ static void start_counters(struct perf_evlist *evlist) } attr->mmap = 1; + attr->inherit = inherit; try_again: if (perf_evsel__open(counter, top.evlist->cpus, - top.evlist->threads, group, inherit) < 0) { + top.evlist->threads, group) < 0) { int err = errno; if (err == EPERM || err == EACCES) { diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index d852cef..45da8d1 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -12,6 +12,7 @@ #include "evlist.h" #include "evsel.h" #include "util.h" +#include "debug.h" #include @@ -250,15 +251,19 @@ int perf_evlist__alloc_mmap(struct perf_evlist *evlist) return evlist->mmap != NULL ? 0 : -ENOMEM; } -static int __perf_evlist__mmap(struct perf_evlist *evlist, int cpu, int prot, - int mask, int fd) +static int __perf_evlist__mmap(struct perf_evlist *evlist, struct perf_evsel *evsel, + int cpu, int prot, int mask, int fd) { evlist->mmap[cpu].prev = 0; evlist->mmap[cpu].mask = mask; evlist->mmap[cpu].base = mmap(NULL, evlist->mmap_len, prot, MAP_SHARED, fd, 0); - if (evlist->mmap[cpu].base == MAP_FAILED) + if (evlist->mmap[cpu].base == MAP_FAILED) { + if (evlist->cpus->map[cpu] == -1 && evsel->attr.inherit) + ui__warning("Inherit is not allowed on per-task " + "events using mmap.\n"); return -1; + } perf_evlist__add_pollfd(evlist, fd); return 0; @@ -312,7 +317,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite) if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, FD(first_evsel, cpu, 0)) != 0) goto out_unmap; - } else if (__perf_evlist__mmap(evlist, cpu, prot, mask, fd) < 0) + } else if (__perf_evlist__mmap(evlist, evsel, cpu, + prot, mask, fd) < 0) goto out_unmap; if ((evsel->attr.read_format & PERF_FORMAT_ID) && diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 662596a..d6fd59b 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -175,7 +175,7 @@ int __perf_evsel__read(struct perf_evsel *evsel, } static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, - struct thread_map *threads, bool group, bool inherit) + struct thread_map *threads, bool group) { int cpu, thread; unsigned long flags = 0; @@ -192,19 +192,6 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, for (cpu = 0; cpu < cpus->nr; cpu++) { int group_fd = -1; - /* - * Don't allow mmap() of inherited per-task counters. This - * would create a performance issue due to all children writing - * to the same buffer. - * - * FIXME: - * Proper fix is not to pass 'inherit' to perf_evsel__open*, - * but a 'flags' parameter, with 'group' folded there as well, - * then introduce a PERF_O_{MMAP,GROUP,INHERIT} enum, and if - * O_MMAP is set, emit a warning if cpu < 0 and O_INHERIT is - * set. Lets go for the minimal fix first tho. - */ - evsel->attr.inherit = (cpus->map[cpu] >= 0) && inherit; for (thread = 0; thread < threads->nr; thread++) { @@ -253,7 +240,7 @@ static struct { }; int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, - struct thread_map *threads, bool group, bool inherit) + struct thread_map *threads, bool group) { if (cpus == NULL) { /* Work around old compiler warnings about strict aliasing */ @@ -263,19 +250,19 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, if (threads == NULL) threads = &empty_thread_map.map; - return __perf_evsel__open(evsel, cpus, threads, group, inherit); + return __perf_evsel__open(evsel, cpus, threads, group); } int perf_evsel__open_per_cpu(struct perf_evsel *evsel, - struct cpu_map *cpus, bool group, bool inherit) + struct cpu_map *cpus, bool group) { - return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group, inherit); + return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group); } int perf_evsel__open_per_thread(struct perf_evsel *evsel, - struct thread_map *threads, bool group, bool inherit) + struct thread_map *threads, bool group) { - return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group, inherit); + return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group); } static int perf_event__parse_id_sample(const union perf_event *event, u64 type, diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 6710ab5..f79bb2c 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -81,11 +81,11 @@ void perf_evsel__free_id(struct perf_evsel *evsel); void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads); int perf_evsel__open_per_cpu(struct perf_evsel *evsel, - struct cpu_map *cpus, bool group, bool inherit); + struct cpu_map *cpus, bool group); int perf_evsel__open_per_thread(struct perf_evsel *evsel, - struct thread_map *threads, bool group, bool inherit); + struct thread_map *threads, bool group); int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, - struct thread_map *threads, bool group, bool inherit); + struct thread_map *threads, bool group); #define perf_evsel__match(evsel, t, c) \ (evsel->attr.type == PERF_TYPE_##t && \ diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c index a9f2d7e..f5e3845 100644 --- a/tools/perf/util/python.c +++ b/tools/perf/util/python.c @@ -498,11 +498,11 @@ static PyObject *pyrf_evsel__open(struct pyrf_evsel *pevsel, struct cpu_map *cpus = NULL; struct thread_map *threads = NULL; PyObject *pcpus = NULL, *pthreads = NULL; - int group = 0, overwrite = 0; - static char *kwlist[] = {"cpus", "threads", "group", "overwrite", NULL, NULL}; + int group = 0, inherit = 0; + static char *kwlist[] = {"cpus", "threads", "group", "inherit", NULL, NULL}; if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|OOii", kwlist, - &pcpus, &pthreads, &group, &overwrite)) + &pcpus, &pthreads, &group, &inherit)) return NULL; if (pthreads != NULL) @@ -511,7 +511,8 @@ static PyObject *pyrf_evsel__open(struct pyrf_evsel *pevsel, if (pcpus != NULL) cpus = ((struct pyrf_cpu_map *)pcpus)->cpus; - if (perf_evsel__open(evsel, cpus, threads, group, overwrite) < 0) { + evsel->attr.inherit = inherit; + if (perf_evsel__open(evsel, cpus, threads, group) < 0) { PyErr_SetFromErrno(PyExc_OSError); return NULL; } -- 1.7.1 -- 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/