lkml.org 
[lkml]   [2020]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2] perf data: Allow to use stdio functions for pipe mode
    Em Sat, Nov 14, 2020 at 09:55:34PM +0100, Jiri Olsa escreveu:
    > 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, tested and applied.

    - Arnaldo

    > 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
    > >
    >

    --

    - Arnaldo

    \
     
     \ /
      Last update: 2020-11-16 17:41    [W:3.283 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site