Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH 4/4] perf inject: Fix output from a file to a pipe | Date | Wed, 7 Jul 2021 11:05:36 -0700 |
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When the input is a regular file but the output is a pipe, it should write a pipe header. But just repiping would write a portion of the existing header which is different in 'size' value. So we need to prevent it and write a new pipe header along with other information like event attributes and features.
This can handle something like this:
# perf record -a -B sleep 1
# perf inject -b -i perf.data | perf report -i -
Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/builtin-inject.c | 57 +++++++++++++++++++++++++++++++++++-- 1 file changed, 55 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index 7c126597d3f5..50ed158c8076 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -918,6 +918,7 @@ int cmd_inject(int argc, const char **argv) .use_stdio = true, }; int ret; + bool repipe = true; struct option options[] = { OPT_BOOLEAN('b', "build-ids", &inject.build_ids, @@ -992,10 +993,18 @@ int cmd_inject(int argc, const char **argv) } data.path = inject.input_name; - if (!strcmp(inject.input_name, "-") || inject.output.is_pipe) + if (!strcmp(inject.input_name, "-") || inject.output.is_pipe) { inject.is_pipe = true; + /* + * Do not repipe header when input is a regular file + * since either it can rewrite the header at the end + * or write a new pipe header. + */ + if (strcmp(inject.input_name, "-")) + repipe = false; + } - inject.session = __perf_session__new(&data, inject.is_pipe, + inject.session = __perf_session__new(&data, repipe, perf_data__fd(&inject.output), &inject.tool); if (IS_ERR(inject.session)) @@ -1004,6 +1013,50 @@ int cmd_inject(int argc, const char **argv) if (zstd_init(&(inject.session->zstd_data), 0) < 0) pr_warning("Decompression initialization failed.\n"); + if (!data.is_pipe && inject.output.is_pipe) { + ret = perf_header__write_pipe(perf_data__fd(&inject.output)); + if (ret < 0) { + pr_err("Couldn't write a new pipe header.\n"); + goto out_delete; + } + + ret = perf_event__synthesize_attrs(&inject.tool, + inject.session->evlist, + perf_event__repipe); + if (ret < 0) { + pr_err("Couldn't inject synthesized attrs.\n"); + goto out_delete; + } + + ret = perf_event__synthesize_features(&inject.tool, + inject.session, + inject.session->evlist, + perf_event__repipe); + if (ret < 0) { + pr_err("Couldn't inject synthesized features.\n"); + goto out_delete; + } + + if (have_tracepoints(&inject.session->evlist->core.entries)) { + /* + * FIXME err <= 0 here actually means that + * there were no tracepoints so its not really + * an error, just that we don't need to + * synthesize anything. We really have to + * return this more properly and also + * propagate errors that now are calling die() + */ + ret = perf_event__synthesize_tracing_data(&inject.tool, + perf_data__fd(&inject.output), + inject.session->evlist, + perf_event__repipe); + if (ret <= 0) { + pr_err("Couldn't inject tracing data.\n"); + goto out_delete; + } + } + } + if (inject.build_ids && !inject.build_id_all) { /* * to make sure the mmap records are ordered correctly -- 2.32.0.93.g670b81a890-goog
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