diff options
| author | David Carrillo-Cisneros <davidcc@google.com> | 2017-07-18 07:25:44 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-07-19 05:14:34 +0300 |
| commit | a02c395cccc95e40b4c506c78857e24fdb049096 (patch) | |
| tree | f26850386eb31985efd9de475441ffca47531142 /tools/perf | |
| parent | 48e5fcea386009fb2515158fdaf8586ce72d86ce (diff) | |
| download | linux-a02c395cccc95e40b4c506c78857e24fdb049096.tar.xz | |
perf header: Make write_pmu_mappings pipe-mode friendly
In pipe-mode, we will operate over a buffer instead of a file descriptor
but write_pmu_mappings uses lseek to move over the perf.data file.
Refactor write_pmu_mappings to avoid the usage of lseek and allow
reusing the same logic in pipe-mode (next patch).
Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170718042549.145161-12-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
| -rw-r--r-- | tools/perf/util/header.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 14db9f204b0a..d5359e3384e3 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -797,11 +797,19 @@ static int write_pmu_mappings(struct feat_fd *ff, struct perf_evlist *evlist __maybe_unused) { struct perf_pmu *pmu = NULL; - off_t offset = lseek(ff->fd, 0, SEEK_CUR); - __u32 pmu_num = 0; + u32 pmu_num = 0; int ret; - /* write real pmu_num later */ + /* + * Do a first pass to count number of pmu to avoid lseek so this + * works in pipe mode as well. + */ + while ((pmu = perf_pmu__scan(pmu))) { + if (!pmu->name) + continue; + pmu_num++; + } + ret = do_write(ff, &pmu_num, sizeof(pmu_num)); if (ret < 0) return ret; @@ -809,7 +817,6 @@ static int write_pmu_mappings(struct feat_fd *ff, while ((pmu = perf_pmu__scan(pmu))) { if (!pmu->name) continue; - pmu_num++; ret = do_write(ff, &pmu->type, sizeof(pmu->type)); if (ret < 0) @@ -820,12 +827,6 @@ static int write_pmu_mappings(struct feat_fd *ff, return ret; } - if (pwrite(ff->fd, &pmu_num, sizeof(pmu_num), offset) != sizeof(pmu_num)) { - /* discard all */ - lseek(ff->fd, offset, SEEK_SET); - return -1; - } - return 0; } |