Messages in this thread | | | Date | Sat, 14 Nov 2020 21:55:34 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH v2] perf data: Allow to use stdio functions for pipe mode |
| |
On Fri, Oct 30, 2020 at 02:47:42PM +0900, Namhyung Kim wrote: > When perf data is in a pipe, it reads each event separately using > read(2) syscall. This is a huge performance bottleneck when > processing large data like in perf inject. Also perf inject needs to > use write(2) syscall for the output. > > So convert it to use buffer I/O functions in stdio library for pipe > data. This makes inject-build-id bench time drops from 20ms to 8ms. > > $ perf bench internals inject-build-id > # Running 'internals/inject-build-id' benchmark: > Average build-id injection took: 8.074 msec (+- 0.013 msec) > Average time per event: 0.792 usec (+- 0.001 usec) > Average memory usage: 8328 KB (+- 0 KB) > Average build-id-all injection took: 5.490 msec (+- 0.008 msec) > Average time per event: 0.538 usec (+- 0.001 usec) > Average memory usage: 7563 KB (+- 0 KB) > > This patch enables it just for perf inject when used with pipe (it's a > default behavior). Maybe we could do it for perf record and/or report > later.. > > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
thanks, jirka
> --- > v2: check result of fdopen() > > tools/perf/builtin-inject.c | 2 ++ > tools/perf/util/data.c | 41 ++++++++++++++++++++++++++++++++++--- > tools/perf/util/data.h | 11 +++++++++- > tools/perf/util/header.c | 8 ++++---- > tools/perf/util/session.c | 7 ++++--- > 5 files changed, 58 insertions(+), 11 deletions(-) > > diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c > index 452a75fe68e5..14d6c88fed76 100644 > --- a/tools/perf/builtin-inject.c > +++ b/tools/perf/builtin-inject.c > @@ -853,10 +853,12 @@ int cmd_inject(int argc, const char **argv) > .output = { > .path = "-", > .mode = PERF_DATA_MODE_WRITE, > + .use_stdio = true, > }, > }; > struct perf_data data = { > .mode = PERF_DATA_MODE_READ, > + .use_stdio = true, > }; > int ret; > > diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c > index c47aa34fdc0a..05bbcb663c41 100644 > --- a/tools/perf/util/data.c > +++ b/tools/perf/util/data.c > @@ -174,8 +174,21 @@ static bool check_pipe(struct perf_data *data) > is_pipe = true; > } > > - if (is_pipe) > - data->file.fd = fd; > + if (is_pipe) { > + if (data->use_stdio) { > + const char *mode; > + > + mode = perf_data__is_read(data) ? "r" : "w"; > + data->file.fptr = fdopen(fd, mode); > + > + if (data->file.fptr == NULL) { > + data->file.fd = fd; > + data->use_stdio = false; > + } > + } else { > + data->file.fd = fd; > + } > + } > > return data->is_pipe = is_pipe; > } > @@ -334,6 +347,9 @@ int perf_data__open(struct perf_data *data) > if (check_pipe(data)) > return 0; > > + /* currently it allows stdio for pipe only */ > + data->use_stdio = false; > + > if (!data->path) > data->path = "perf.data"; > > @@ -353,7 +369,21 @@ void perf_data__close(struct perf_data *data) > perf_data__close_dir(data); > > zfree(&data->file.path); > - close(data->file.fd); > + > + if (data->use_stdio) > + fclose(data->file.fptr); > + else > + close(data->file.fd); > +} > + > +ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size) > +{ > + if (data->use_stdio) { > + if (fread(buf, size, 1, data->file.fptr) == 1) > + return size; > + return feof(data->file.fptr) ? 0 : -1; > + } > + return readn(data->file.fd, buf, size); > } > > ssize_t perf_data_file__write(struct perf_data_file *file, > @@ -365,6 +395,11 @@ ssize_t perf_data_file__write(struct perf_data_file *file, > ssize_t perf_data__write(struct perf_data *data, > void *buf, size_t size) > { > + if (data->use_stdio) { > + if (fwrite(buf, size, 1, data->file.fptr) == 1) > + return size; > + return -1; > + } > return perf_data_file__write(&data->file, buf, size); > } > > diff --git a/tools/perf/util/data.h b/tools/perf/util/data.h > index 75947ef6bc17..c563fcbb0288 100644 > --- a/tools/perf/util/data.h > +++ b/tools/perf/util/data.h > @@ -2,6 +2,7 @@ > #ifndef __PERF_DATA_H > #define __PERF_DATA_H > > +#include <stdio.h> > #include <stdbool.h> > > enum perf_data_mode { > @@ -16,7 +17,10 @@ enum perf_dir_version { > > struct perf_data_file { > char *path; > - int fd; > + union { > + int fd; > + FILE *fptr; > + }; > unsigned long size; > }; > > @@ -26,6 +30,7 @@ struct perf_data { > bool is_pipe; > bool is_dir; > bool force; > + bool use_stdio; > enum perf_data_mode mode; > > struct { > @@ -62,11 +67,15 @@ static inline bool perf_data__is_single_file(struct perf_data *data) > > static inline int perf_data__fd(struct perf_data *data) > { > + if (data->use_stdio) > + return fileno(data->file.fptr); > + > return data->file.fd; > } > > int perf_data__open(struct perf_data *data); > void perf_data__close(struct perf_data *data); > +ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size); > ssize_t perf_data__write(struct perf_data *data, > void *buf, size_t size); > ssize_t perf_data_file__write(struct perf_data_file *file, > diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c > index be850e9f8852..d9a70154426b 100644 > --- a/tools/perf/util/header.c > +++ b/tools/perf/util/header.c > @@ -3652,7 +3652,8 @@ static int perf_file_section__process(struct perf_file_section *section, > } > > static int perf_file_header__read_pipe(struct perf_pipe_file_header *header, > - struct perf_header *ph, int fd, > + struct perf_header *ph, > + struct perf_data* data, > bool repipe) > { > struct feat_fd ff = { > @@ -3661,7 +3662,7 @@ static int perf_file_header__read_pipe(struct perf_pipe_file_header *header, > }; > ssize_t ret; > > - ret = readn(fd, header, sizeof(*header)); > + ret = perf_data__read(data, header, sizeof(*header)); > if (ret <= 0) > return -1; > > @@ -3684,8 +3685,7 @@ static int perf_header__read_pipe(struct perf_session *session) > struct perf_header *header = &session->header; > struct perf_pipe_file_header f_header; > > - if (perf_file_header__read_pipe(&f_header, header, > - perf_data__fd(session->data), > + if (perf_file_header__read_pipe(&f_header, header, session->data, > session->repipe) < 0) { > pr_debug("incompatible file format\n"); > return -EINVAL; > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index 7a5f03764702..f901a09a58e4 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -1923,7 +1923,6 @@ static int __perf_session__process_pipe_events(struct perf_session *session) > { > struct ordered_events *oe = &session->ordered_events; > struct perf_tool *tool = session->tool; > - int fd = perf_data__fd(session->data); > union perf_event *event; > uint32_t size, cur_size = 0; > void *buf = NULL; > @@ -1943,7 +1942,8 @@ static int __perf_session__process_pipe_events(struct perf_session *session) > ordered_events__set_copy_on_queue(oe, true); > more: > event = buf; > - err = readn(fd, event, sizeof(struct perf_event_header)); > + err = perf_data__read(session->data, event, > + sizeof(struct perf_event_header)); > if (err <= 0) { > if (err == 0) > goto done; > @@ -1975,7 +1975,8 @@ static int __perf_session__process_pipe_events(struct perf_session *session) > p += sizeof(struct perf_event_header); > > if (size - sizeof(struct perf_event_header)) { > - err = readn(fd, p, size - sizeof(struct perf_event_header)); > + err = perf_data__read(session->data, p, > + size - sizeof(struct perf_event_header)); > if (err <= 0) { > if (err == 0) { > pr_err("unexpected end of event stream\n"); > -- > 2.29.1.341.ge80a0c044ae-goog >
| |