* [PATCH v3 0/2] perf tools: Backward ring buffer support @ 2016-05-09 1:47 Wang Nan 2016-05-09 1:47 ` [PATCH v3 1/2] perf tools: Support reading from backward ring buffer Wang Nan 2016-05-09 1:47 ` [PATCH v3 2/2] perf tests: Add test to check " Wang Nan 0 siblings, 2 replies; 6+ messages in thread From: Wang Nan @ 2016-05-09 1:47 UTC (permalink / raw) To: acme; +Cc: linux-kernel, lizefan, pi3orama, Wang Nan Commit 9ecda41acb97 ("perf/core: Add ::write_backward attribute to perf event") introduces backward ring buffer. This 2 patches add basic support for reading from it, and add a new test case for it. v2 -> v3: Improve commit message, add more comments (patch 1/2). patch 1-2/4 in v2 have been collected so remove them. v1 -> v2: Patch 1/5 in v1 has been collected by perf/core, so remove it; Change function names in patch 2/5 in v1 (1/4 in v2): __perf_evlist__mmap_read -> perf_mmap__read Wang Nan (2): perf tools: Support reading from backward ring buffer perf tests: Add test to check backward ring buffer tools/perf/tests/Build | 1 + tools/perf/tests/backward-ring-buffer.c | 151 ++++++++++++++++++++++++++++++++ tools/perf/tests/builtin-test.c | 4 + tools/perf/tests/tests.h | 1 + tools/perf/util/evlist.c | 50 +++++++++++ tools/perf/util/evlist.h | 4 + 6 files changed, 211 insertions(+) create mode 100644 tools/perf/tests/backward-ring-buffer.c -- 1.8.3.4 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v3 1/2] perf tools: Support reading from backward ring buffer 2016-05-09 1:47 [PATCH v3 0/2] perf tools: Backward ring buffer support Wang Nan @ 2016-05-09 1:47 ` Wang Nan 2016-05-10 20:31 ` [tip:perf/core] " tip-bot for Wang Nan 2016-05-09 1:47 ` [PATCH v3 2/2] perf tests: Add test to check " Wang Nan 1 sibling, 1 reply; 6+ messages in thread From: Wang Nan @ 2016-05-09 1:47 UTC (permalink / raw) To: acme Cc: linux-kernel, lizefan, pi3orama, Wang Nan, Arnaldo Carvalho de Melo, Peter Zijlstra perf_evlist__mmap_read_backward() is introduced for reading backward ring buffer. Since direction for reading such ring buffer is different from the direction kernel writing to it, and since user need to fetch most recent record from it, a perf_evlist__mmap_read_catchup() is introduced to move the reading pointer to the end of the buffer. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com --- tools/perf/util/evlist.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/evlist.h | 4 ++++ 2 files changed, 54 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 17cd014..c4bfe11 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -766,6 +766,56 @@ union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx) return perf_mmap__read(md, evlist->overwrite, old, head, &md->prev); } +union perf_event * +perf_evlist__mmap_read_backward(struct perf_evlist *evlist, int idx) +{ + struct perf_mmap *md = &evlist->mmap[idx]; + u64 head, end; + u64 start = md->prev; + + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!atomic_read(&md->refcnt)) + return NULL; + + head = perf_mmap__read_head(md); + if (!head) + return NULL; + + /* + * 'head' pointer starts from 0. Kernel minus sizeof(record) form + * it each time when kernel writes to it, so in fact 'head' is + * negative. 'end' pointer is made manually by adding the size of + * the ring buffer to 'head' pointer, means the validate data can + * read is the whole ring buffer. If 'end' is positive, the ring + * buffer has not fully filled, so we must adjust 'end' to 0. + * + * However, since both 'head' and 'end' is unsigned, we can't + * simply compare 'end' against 0. Here we compare '-head' and + * the size of the ring buffer, where -head is the number of bytes + * kernel write to the ring buffer. + */ + if (-head < (u64)(md->mask + 1)) + end = 0; + else + end = head + md->mask + 1; + + return perf_mmap__read(md, false, start, end, &md->prev); +} + +void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx) +{ + struct perf_mmap *md = &evlist->mmap[idx]; + u64 head; + + if (!atomic_read(&md->refcnt)) + return; + + head = perf_mmap__read_head(md); + md->prev = head; +} + static bool perf_mmap__empty(struct perf_mmap *md) { return perf_mmap__read_head(md) == md->prev && !md->auxtrace_mmap.base; diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 208897a..85d1b59 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -129,6 +129,10 @@ struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id); union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx); +union perf_event *perf_evlist__mmap_read_backward(struct perf_evlist *evlist, + int idx); +void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx); + void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx); int perf_evlist__open(struct perf_evlist *evlist); -- 1.8.3.4 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [tip:perf/core] perf tools: Support reading from backward ring buffer 2016-05-09 1:47 ` [PATCH v3 1/2] perf tools: Support reading from backward ring buffer Wang Nan @ 2016-05-10 20:31 ` tip-bot for Wang Nan 0 siblings, 0 replies; 6+ messages in thread From: tip-bot for Wang Nan @ 2016-05-10 20:31 UTC (permalink / raw) To: linux-tip-commits Cc: tglx, lizefan, acme, mingo, wangnan0, hpa, linux-kernel, peterz Commit-ID: e24c7520ea9c3e5bb51592c2134aafbf75a3f88a Gitweb: http://git.kernel.org/tip/e24c7520ea9c3e5bb51592c2134aafbf75a3f88a Author: Wang Nan <wangnan0@huawei.com> AuthorDate: Mon, 9 May 2016 01:47:50 +0000 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitDate: Mon, 9 May 2016 17:20:53 -0300 perf tools: Support reading from backward ring buffer perf_evlist__mmap_read_backward() is introduced for reading backward ring buffer. Since direction for reading such ring buffer is different from the direction kernel writing to it, and since user need to fetch most recent record from it, a perf_evlist__mmap_read_catchup() is introduced to move the reading pointer to the end of the buffer. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1462758471-89706-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/evlist.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/evlist.h | 4 ++++ 2 files changed, 54 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 17cd014..c4bfe11 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -766,6 +766,56 @@ union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx) return perf_mmap__read(md, evlist->overwrite, old, head, &md->prev); } +union perf_event * +perf_evlist__mmap_read_backward(struct perf_evlist *evlist, int idx) +{ + struct perf_mmap *md = &evlist->mmap[idx]; + u64 head, end; + u64 start = md->prev; + + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!atomic_read(&md->refcnt)) + return NULL; + + head = perf_mmap__read_head(md); + if (!head) + return NULL; + + /* + * 'head' pointer starts from 0. Kernel minus sizeof(record) form + * it each time when kernel writes to it, so in fact 'head' is + * negative. 'end' pointer is made manually by adding the size of + * the ring buffer to 'head' pointer, means the validate data can + * read is the whole ring buffer. If 'end' is positive, the ring + * buffer has not fully filled, so we must adjust 'end' to 0. + * + * However, since both 'head' and 'end' is unsigned, we can't + * simply compare 'end' against 0. Here we compare '-head' and + * the size of the ring buffer, where -head is the number of bytes + * kernel write to the ring buffer. + */ + if (-head < (u64)(md->mask + 1)) + end = 0; + else + end = head + md->mask + 1; + + return perf_mmap__read(md, false, start, end, &md->prev); +} + +void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx) +{ + struct perf_mmap *md = &evlist->mmap[idx]; + u64 head; + + if (!atomic_read(&md->refcnt)) + return; + + head = perf_mmap__read_head(md); + md->prev = head; +} + static bool perf_mmap__empty(struct perf_mmap *md) { return perf_mmap__read_head(md) == md->prev && !md->auxtrace_mmap.base; diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 208897a..85d1b59 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -129,6 +129,10 @@ struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id); union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx); +union perf_event *perf_evlist__mmap_read_backward(struct perf_evlist *evlist, + int idx); +void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx); + void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx); int perf_evlist__open(struct perf_evlist *evlist); ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v3 2/2] perf tests: Add test to check backward ring buffer 2016-05-09 1:47 [PATCH v3 0/2] perf tools: Backward ring buffer support Wang Nan 2016-05-09 1:47 ` [PATCH v3 1/2] perf tools: Support reading from backward ring buffer Wang Nan @ 2016-05-09 1:47 ` Wang Nan 2016-05-09 21:12 ` Arnaldo Carvalho de Melo 2016-05-10 20:32 ` [tip:perf/core] " tip-bot for Wang Nan 1 sibling, 2 replies; 6+ messages in thread From: Wang Nan @ 2016-05-09 1:47 UTC (permalink / raw) To: acme Cc: linux-kernel, lizefan, pi3orama, Wang Nan, Arnaldo Carvalho de Melo, Peter Zijlstra This test checks reading from backward ring buffer. Test result: # ~/perf test 'ring buffer' 45: Test backward reading from ring buffer : Ok Test case is a while loop which calls prctl(PR_SET_NAME) multiple times. Each prctl should issue 2 events: one PERF_RECORD_SAMPLE, one PERF_RECORD_COMM. The first round creates a relative large ring buffer (256 pages). It can afford all events. Read from it and check the count of each type of events. The second round creates a small ring buffer (1 page) and makes it overwritable. Check the correctness of the buffer. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com --- tools/perf/tests/Build | 1 + tools/perf/tests/backward-ring-buffer.c | 151 ++++++++++++++++++++++++++++++++ tools/perf/tests/builtin-test.c | 4 + tools/perf/tests/tests.h | 1 + 4 files changed, 157 insertions(+) create mode 100644 tools/perf/tests/backward-ring-buffer.c diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build index 449fe97..66a2898 100644 --- a/tools/perf/tests/Build +++ b/tools/perf/tests/Build @@ -38,6 +38,7 @@ perf-y += cpumap.o perf-y += stat.o perf-y += event_update.o perf-y += event-times.o +perf-y += backward-ring-buffer.o $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build $(call rule_mkdir) diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c new file mode 100644 index 0000000..d9ba991 --- /dev/null +++ b/tools/perf/tests/backward-ring-buffer.c @@ -0,0 +1,151 @@ +/* + * Test backward bit in event attribute, read ring buffer from end to + * beginning + */ + +#include <perf.h> +#include <evlist.h> +#include <sys/prctl.h> +#include "tests.h" +#include "debug.h" + +#define NR_ITERS 111 + +static void testcase(void) +{ + int i; + + for (i = 0; i < NR_ITERS; i++) { + char proc_name[10]; + + snprintf(proc_name, sizeof(proc_name), "p:%d\n", i); + prctl(PR_SET_NAME, proc_name); + } +} + +static int count_samples(struct perf_evlist *evlist, int *sample_count, + int *comm_count) +{ + int i; + + for (i = 0; i < evlist->nr_mmaps; i++) { + union perf_event *event; + + perf_evlist__mmap_read_catchup(evlist, i); + while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) { + const u32 type = event->header.type; + + switch (type) { + case PERF_RECORD_SAMPLE: + (*sample_count)++; + break; + case PERF_RECORD_COMM: + (*comm_count)++; + break; + default: + pr_err("Unexpected record of type %d\n", type); + return TEST_FAIL; + } + } + } + return TEST_OK; +} + +static int do_test(struct perf_evlist *evlist, int mmap_pages, + int *sample_count, int *comm_count) +{ + int err; + char sbuf[STRERR_BUFSIZE]; + + err = perf_evlist__mmap(evlist, mmap_pages, true); + if (err < 0) { + pr_debug("perf_evlist__mmap: %s\n", + strerror_r(errno, sbuf, sizeof(sbuf))); + return TEST_FAIL; + } + + perf_evlist__enable(evlist); + testcase(); + perf_evlist__disable(evlist); + + err = count_samples(evlist, sample_count, comm_count); + perf_evlist__munmap(evlist); + return err; +} + + +int test__backward_ring_buffer(int subtest __maybe_unused) +{ + int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0; + char pid[16], sbuf[STRERR_BUFSIZE]; + struct perf_evlist *evlist; + struct perf_evsel *evsel __maybe_unused; + struct parse_events_error parse_error; + struct record_opts opts = { + .target = { + .uid = UINT_MAX, + .uses_mmap = true, + }, + .freq = 0, + .mmap_pages = 256, + .default_interval = 1, + }; + + snprintf(pid, sizeof(pid), "%d", getpid()); + pid[sizeof(pid) - 1] = '\0'; + opts.target.tid = opts.target.pid = pid; + + evlist = perf_evlist__new(); + if (!evlist) { + pr_debug("No ehough memory to create evlist\n"); + return TEST_FAIL; + } + + err = perf_evlist__create_maps(evlist, &opts.target); + if (err < 0) { + pr_debug("Not enough memory to create thread/cpu maps\n"); + goto out_delete_evlist; + } + + bzero(&parse_error, sizeof(parse_error)); + err = parse_events(evlist, "syscalls:sys_enter_prctl", &parse_error); + if (err) { + pr_debug("Failed to parse tracepoint event, try use root\n"); + ret = TEST_SKIP; + goto out_delete_evlist; + } + + perf_evlist__config(evlist, &opts, NULL); + + /* Set backward bit, ring buffer should be writing from end */ + evlist__for_each(evlist, evsel) + evsel->attr.write_backward = 1; + + err = perf_evlist__open(evlist); + if (err < 0) { + pr_debug("perf_evlist__open: %s\n", + strerror_r(errno, sbuf, sizeof(sbuf))); + goto out_delete_evlist; + } + + ret = TEST_FAIL; + err = do_test(evlist, opts.mmap_pages, &sample_count, + &comm_count); + if (err != TEST_OK) + goto out_delete_evlist; + + if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) { + pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n", + sample_count, comm_count); + goto out_delete_evlist; + } + + err = do_test(evlist, 1, &sample_count, &comm_count); + if (err != TEST_OK) + goto out_delete_evlist; + + ret = TEST_OK; +out_delete_evlist: + perf_evlist__delete(evlist); + return ret; +} diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index 93c4670..0e95c20 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -208,6 +208,10 @@ static struct test generic_tests[] = { .func = test__event_times, }, { + .desc = "Test backward reading from ring buffer", + .func = test__backward_ring_buffer, + }, + { .func = NULL, }, }; diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h index 0fc9469..c57e72c 100644 --- a/tools/perf/tests/tests.h +++ b/tools/perf/tests/tests.h @@ -86,6 +86,7 @@ int test__synthesize_stat(int subtest); int test__synthesize_stat_round(int subtest); int test__event_update(int subtest); int test__event_times(int subtest); +int test__backward_ring_buffer(int subtest); #if defined(__arm__) || defined(__aarch64__) #ifdef HAVE_DWARF_UNWIND_SUPPORT -- 1.8.3.4 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v3 2/2] perf tests: Add test to check backward ring buffer 2016-05-09 1:47 ` [PATCH v3 2/2] perf tests: Add test to check " Wang Nan @ 2016-05-09 21:12 ` Arnaldo Carvalho de Melo 2016-05-10 20:32 ` [tip:perf/core] " tip-bot for Wang Nan 1 sibling, 0 replies; 6+ messages in thread From: Arnaldo Carvalho de Melo @ 2016-05-09 21:12 UTC (permalink / raw) To: Wang Nan; +Cc: acme, linux-kernel, lizefan, pi3orama, Peter Zijlstra Em Mon, May 09, 2016 at 01:47:51AM +0000, Wang Nan escreveu: > This test checks reading from backward ring buffer. > > Test result: > > # ~/perf test 'ring buffer' > 45: Test backward reading from ring buffer : Ok Thanks, applied and also I added a patch to show that bit when using -vv, i.e.: # perf test -vv back 45: Test backward reading from ring buffer : --- start --- <SNIP> ------------------------------------------------------------ perf_event_attr: type 2 size 112 config 0x98 { sample_period, sample_freq } 1 sample_type IP|TID|TIME|CPU|PERIOD|RAW disabled 1 mmap 1 comm 1 task 1 sample_id_all 1 exclude_guest 1 mmap2 1 comm_exec 1 write_backward 1 ------------------------------------------------------------ <SNIP> > Test case is a while loop which calls prctl(PR_SET_NAME) multiple > times. Each prctl should issue 2 events: one PERF_RECORD_SAMPLE, > one PERF_RECORD_COMM. > > The first round creates a relative large ring buffer (256 pages). It > can afford all events. Read from it and check the count of each type of > events. > > The second round creates a small ring buffer (1 page) and makes it > overwritable. Check the correctness of the buffer. > > Signed-off-by: Wang Nan <wangnan0@huawei.com> > Cc: Arnaldo Carvalho de Melo <acme@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Zefan Li <lizefan@huawei.com> > Cc: pi3orama@163.com > --- > tools/perf/tests/Build | 1 + > tools/perf/tests/backward-ring-buffer.c | 151 ++++++++++++++++++++++++++++++++ > tools/perf/tests/builtin-test.c | 4 + > tools/perf/tests/tests.h | 1 + > 4 files changed, 157 insertions(+) > create mode 100644 tools/perf/tests/backward-ring-buffer.c > > diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build > index 449fe97..66a2898 100644 > --- a/tools/perf/tests/Build > +++ b/tools/perf/tests/Build > @@ -38,6 +38,7 @@ perf-y += cpumap.o > perf-y += stat.o > perf-y += event_update.o > perf-y += event-times.o > +perf-y += backward-ring-buffer.o > > $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build > $(call rule_mkdir) > diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c > new file mode 100644 > index 0000000..d9ba991 > --- /dev/null > +++ b/tools/perf/tests/backward-ring-buffer.c > @@ -0,0 +1,151 @@ > +/* > + * Test backward bit in event attribute, read ring buffer from end to > + * beginning > + */ > + > +#include <perf.h> > +#include <evlist.h> > +#include <sys/prctl.h> > +#include "tests.h" > +#include "debug.h" > + > +#define NR_ITERS 111 > + > +static void testcase(void) > +{ > + int i; > + > + for (i = 0; i < NR_ITERS; i++) { > + char proc_name[10]; > + > + snprintf(proc_name, sizeof(proc_name), "p:%d\n", i); > + prctl(PR_SET_NAME, proc_name); > + } > +} > + > +static int count_samples(struct perf_evlist *evlist, int *sample_count, > + int *comm_count) > +{ > + int i; > + > + for (i = 0; i < evlist->nr_mmaps; i++) { > + union perf_event *event; > + > + perf_evlist__mmap_read_catchup(evlist, i); > + while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) { > + const u32 type = event->header.type; > + > + switch (type) { > + case PERF_RECORD_SAMPLE: > + (*sample_count)++; > + break; > + case PERF_RECORD_COMM: > + (*comm_count)++; > + break; > + default: > + pr_err("Unexpected record of type %d\n", type); > + return TEST_FAIL; > + } > + } > + } > + return TEST_OK; > +} > + > +static int do_test(struct perf_evlist *evlist, int mmap_pages, > + int *sample_count, int *comm_count) > +{ > + int err; > + char sbuf[STRERR_BUFSIZE]; > + > + err = perf_evlist__mmap(evlist, mmap_pages, true); > + if (err < 0) { > + pr_debug("perf_evlist__mmap: %s\n", > + strerror_r(errno, sbuf, sizeof(sbuf))); > + return TEST_FAIL; > + } > + > + perf_evlist__enable(evlist); > + testcase(); > + perf_evlist__disable(evlist); > + > + err = count_samples(evlist, sample_count, comm_count); > + perf_evlist__munmap(evlist); > + return err; > +} > + > + > +int test__backward_ring_buffer(int subtest __maybe_unused) > +{ > + int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0; > + char pid[16], sbuf[STRERR_BUFSIZE]; > + struct perf_evlist *evlist; > + struct perf_evsel *evsel __maybe_unused; > + struct parse_events_error parse_error; > + struct record_opts opts = { > + .target = { > + .uid = UINT_MAX, > + .uses_mmap = true, > + }, > + .freq = 0, > + .mmap_pages = 256, > + .default_interval = 1, > + }; > + > + snprintf(pid, sizeof(pid), "%d", getpid()); > + pid[sizeof(pid) - 1] = '\0'; > + opts.target.tid = opts.target.pid = pid; > + > + evlist = perf_evlist__new(); > + if (!evlist) { > + pr_debug("No ehough memory to create evlist\n"); > + return TEST_FAIL; > + } > + > + err = perf_evlist__create_maps(evlist, &opts.target); > + if (err < 0) { > + pr_debug("Not enough memory to create thread/cpu maps\n"); > + goto out_delete_evlist; > + } > + > + bzero(&parse_error, sizeof(parse_error)); > + err = parse_events(evlist, "syscalls:sys_enter_prctl", &parse_error); > + if (err) { > + pr_debug("Failed to parse tracepoint event, try use root\n"); > + ret = TEST_SKIP; > + goto out_delete_evlist; > + } > + > + perf_evlist__config(evlist, &opts, NULL); > + > + /* Set backward bit, ring buffer should be writing from end */ > + evlist__for_each(evlist, evsel) > + evsel->attr.write_backward = 1; > + > + err = perf_evlist__open(evlist); > + if (err < 0) { > + pr_debug("perf_evlist__open: %s\n", > + strerror_r(errno, sbuf, sizeof(sbuf))); > + goto out_delete_evlist; > + } > + > + ret = TEST_FAIL; > + err = do_test(evlist, opts.mmap_pages, &sample_count, > + &comm_count); > + if (err != TEST_OK) > + goto out_delete_evlist; > + > + if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) { > + pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n", > + sample_count, comm_count); > + goto out_delete_evlist; > + } > + > + err = do_test(evlist, 1, &sample_count, &comm_count); > + if (err != TEST_OK) > + goto out_delete_evlist; > + > + ret = TEST_OK; > +out_delete_evlist: > + perf_evlist__delete(evlist); > + return ret; > +} > diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c > index 93c4670..0e95c20 100644 > --- a/tools/perf/tests/builtin-test.c > +++ b/tools/perf/tests/builtin-test.c > @@ -208,6 +208,10 @@ static struct test generic_tests[] = { > .func = test__event_times, > }, > { > + .desc = "Test backward reading from ring buffer", > + .func = test__backward_ring_buffer, > + }, > + { > .func = NULL, > }, > }; > diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h > index 0fc9469..c57e72c 100644 > --- a/tools/perf/tests/tests.h > +++ b/tools/perf/tests/tests.h > @@ -86,6 +86,7 @@ int test__synthesize_stat(int subtest); > int test__synthesize_stat_round(int subtest); > int test__event_update(int subtest); > int test__event_times(int subtest); > +int test__backward_ring_buffer(int subtest); > > #if defined(__arm__) || defined(__aarch64__) > #ifdef HAVE_DWARF_UNWIND_SUPPORT > -- > 1.8.3.4 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [tip:perf/core] perf tests: Add test to check backward ring buffer 2016-05-09 1:47 ` [PATCH v3 2/2] perf tests: Add test to check " Wang Nan 2016-05-09 21:12 ` Arnaldo Carvalho de Melo @ 2016-05-10 20:32 ` tip-bot for Wang Nan 1 sibling, 0 replies; 6+ messages in thread From: tip-bot for Wang Nan @ 2016-05-10 20:32 UTC (permalink / raw) To: linux-tip-commits Cc: mingo, hpa, lizefan, acme, tglx, wangnan0, peterz, linux-kernel Commit-ID: ee74701ed8add8ad13e642e8618b51fd75add32d Gitweb: http://git.kernel.org/tip/ee74701ed8add8ad13e642e8618b51fd75add32d Author: Wang Nan <wangnan0@huawei.com> AuthorDate: Mon, 9 May 2016 01:47:51 +0000 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitDate: Mon, 9 May 2016 18:11:22 -0300 perf tests: Add test to check backward ring buffer This test checks reading from backward ring buffer. Test result: # ~/perf test 'ring buffer' 45: Test backward reading from ring buffer : Ok The test case is a while loop which calls prctl(PR_SET_NAME) multiple times. Each prctl should issue 2 events: one PERF_RECORD_SAMPLE, one PERF_RECORD_COMM. The first round creates a relative large ring buffer (256 pages). It can afford all events. Read from it and check the count of each type of events. The second round creates a small ring buffer (1 page) and makes it overwritable. Check the correctness of the buffer. Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1462758471-89706-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/tests/Build | 1 + tools/perf/tests/backward-ring-buffer.c | 151 ++++++++++++++++++++++++++++++++ tools/perf/tests/builtin-test.c | 4 + tools/perf/tests/tests.h | 1 + 4 files changed, 157 insertions(+) diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build index 449fe97..66a2898 100644 --- a/tools/perf/tests/Build +++ b/tools/perf/tests/Build @@ -38,6 +38,7 @@ perf-y += cpumap.o perf-y += stat.o perf-y += event_update.o perf-y += event-times.o +perf-y += backward-ring-buffer.o $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build $(call rule_mkdir) diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c new file mode 100644 index 0000000..d9ba991 --- /dev/null +++ b/tools/perf/tests/backward-ring-buffer.c @@ -0,0 +1,151 @@ +/* + * Test backward bit in event attribute, read ring buffer from end to + * beginning + */ + +#include <perf.h> +#include <evlist.h> +#include <sys/prctl.h> +#include "tests.h" +#include "debug.h" + +#define NR_ITERS 111 + +static void testcase(void) +{ + int i; + + for (i = 0; i < NR_ITERS; i++) { + char proc_name[10]; + + snprintf(proc_name, sizeof(proc_name), "p:%d\n", i); + prctl(PR_SET_NAME, proc_name); + } +} + +static int count_samples(struct perf_evlist *evlist, int *sample_count, + int *comm_count) +{ + int i; + + for (i = 0; i < evlist->nr_mmaps; i++) { + union perf_event *event; + + perf_evlist__mmap_read_catchup(evlist, i); + while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) { + const u32 type = event->header.type; + + switch (type) { + case PERF_RECORD_SAMPLE: + (*sample_count)++; + break; + case PERF_RECORD_COMM: + (*comm_count)++; + break; + default: + pr_err("Unexpected record of type %d\n", type); + return TEST_FAIL; + } + } + } + return TEST_OK; +} + +static int do_test(struct perf_evlist *evlist, int mmap_pages, + int *sample_count, int *comm_count) +{ + int err; + char sbuf[STRERR_BUFSIZE]; + + err = perf_evlist__mmap(evlist, mmap_pages, true); + if (err < 0) { + pr_debug("perf_evlist__mmap: %s\n", + strerror_r(errno, sbuf, sizeof(sbuf))); + return TEST_FAIL; + } + + perf_evlist__enable(evlist); + testcase(); + perf_evlist__disable(evlist); + + err = count_samples(evlist, sample_count, comm_count); + perf_evlist__munmap(evlist); + return err; +} + + +int test__backward_ring_buffer(int subtest __maybe_unused) +{ + int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0; + char pid[16], sbuf[STRERR_BUFSIZE]; + struct perf_evlist *evlist; + struct perf_evsel *evsel __maybe_unused; + struct parse_events_error parse_error; + struct record_opts opts = { + .target = { + .uid = UINT_MAX, + .uses_mmap = true, + }, + .freq = 0, + .mmap_pages = 256, + .default_interval = 1, + }; + + snprintf(pid, sizeof(pid), "%d", getpid()); + pid[sizeof(pid) - 1] = '\0'; + opts.target.tid = opts.target.pid = pid; + + evlist = perf_evlist__new(); + if (!evlist) { + pr_debug("No ehough memory to create evlist\n"); + return TEST_FAIL; + } + + err = perf_evlist__create_maps(evlist, &opts.target); + if (err < 0) { + pr_debug("Not enough memory to create thread/cpu maps\n"); + goto out_delete_evlist; + } + + bzero(&parse_error, sizeof(parse_error)); + err = parse_events(evlist, "syscalls:sys_enter_prctl", &parse_error); + if (err) { + pr_debug("Failed to parse tracepoint event, try use root\n"); + ret = TEST_SKIP; + goto out_delete_evlist; + } + + perf_evlist__config(evlist, &opts, NULL); + + /* Set backward bit, ring buffer should be writing from end */ + evlist__for_each(evlist, evsel) + evsel->attr.write_backward = 1; + + err = perf_evlist__open(evlist); + if (err < 0) { + pr_debug("perf_evlist__open: %s\n", + strerror_r(errno, sbuf, sizeof(sbuf))); + goto out_delete_evlist; + } + + ret = TEST_FAIL; + err = do_test(evlist, opts.mmap_pages, &sample_count, + &comm_count); + if (err != TEST_OK) + goto out_delete_evlist; + + if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) { + pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n", + sample_count, comm_count); + goto out_delete_evlist; + } + + err = do_test(evlist, 1, &sample_count, &comm_count); + if (err != TEST_OK) + goto out_delete_evlist; + + ret = TEST_OK; +out_delete_evlist: + perf_evlist__delete(evlist); + return ret; +} diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index 93c4670..0e95c20 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -208,6 +208,10 @@ static struct test generic_tests[] = { .func = test__event_times, }, { + .desc = "Test backward reading from ring buffer", + .func = test__backward_ring_buffer, + }, + { .func = NULL, }, }; diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h index 0fc9469..c57e72c 100644 --- a/tools/perf/tests/tests.h +++ b/tools/perf/tests/tests.h @@ -86,6 +86,7 @@ int test__synthesize_stat(int subtest); int test__synthesize_stat_round(int subtest); int test__event_update(int subtest); int test__event_times(int subtest); +int test__backward_ring_buffer(int subtest); #if defined(__arm__) || defined(__aarch64__) #ifdef HAVE_DWARF_UNWIND_SUPPORT ^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-05-10 20:32 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2016-05-09 1:47 [PATCH v3 0/2] perf tools: Backward ring buffer support Wang Nan 2016-05-09 1:47 ` [PATCH v3 1/2] perf tools: Support reading from backward ring buffer Wang Nan 2016-05-10 20:31 ` [tip:perf/core] " tip-bot for Wang Nan 2016-05-09 1:47 ` [PATCH v3 2/2] perf tests: Add test to check " Wang Nan 2016-05-09 21:12 ` Arnaldo Carvalho de Melo 2016-05-10 20:32 ` [tip:perf/core] " tip-bot for Wang Nan
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