Messages in this thread Patch in this message | | | From | Alexey Bayduraev <> | Subject | [PATCH v10 22/24] perf session: Move map/unmap into reader__mmap function | Date | Mon, 12 Jul 2021 09:46:22 +0300 |
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Moving mapping and unmapping code into reader__mmap, so the mmap code is located together. Moving head/file_offset computation into reader__mmap function, so all the offset computation is located together and in one place only.
Design and implementation are based on the prototype [1], [2].
[1] git clone https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git -b perf/record_threads [2] https://lore.kernel.org/lkml/20180913125450.21342-1-jolsa@kernel.org/
Suggested-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com> --- tools/perf/util/session.c | 60 +++++++++++++++++++++++---------------- 1 file changed, 35 insertions(+), 25 deletions(-)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index f25f5f33bec1..8be60ad6c818 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -2217,14 +2217,11 @@ static int reader__init(struct reader *rd, bool *one_mmap) { struct reader_state *st = &rd->state; - u64 page_offset; char **mmaps = st->mmaps; pr_debug("reader processing %s\n", rd->path); - page_offset = page_size * (rd->data_offset / page_size); - st->file_offset = page_offset; - st->head = rd->data_offset - page_offset; + st->head = rd->data_offset; st->data_size = rd->data_size + rd->data_offset; @@ -2244,15 +2241,12 @@ reader__init(struct reader *rd, bool *one_mmap) } static int -reader__process_events(struct reader *rd, struct perf_session *session, - struct ui_progress *prog) +reader__mmap(struct reader *rd, struct perf_session *session) { struct reader_state *st = &rd->state; - u64 page_offset, size; - int err = 0, mmap_prot, mmap_flags; + int mmap_prot, mmap_flags; char *buf, **mmaps = st->mmaps; - union perf_event *event; - s64 skip; + u64 page_offset; mmap_prot = PROT_READ; mmap_flags = MAP_SHARED; @@ -2263,20 +2257,45 @@ reader__process_events(struct reader *rd, struct perf_session *session, mmap_prot |= PROT_WRITE; mmap_flags = MAP_PRIVATE; } -remap: + + if (mmaps[st->mmap_idx]) { + munmap(mmaps[st->mmap_idx], st->mmap_size); + mmaps[st->mmap_idx] = NULL; + } + + page_offset = page_size * (st->head / page_size); + st->file_offset += page_offset; + st->head -= page_offset; + buf = mmap(NULL, st->mmap_size, mmap_prot, mmap_flags, rd->fd, st->file_offset); if (buf == MAP_FAILED) { pr_err("failed to mmap file\n"); - err = -errno; - goto out; + return -errno; } mmaps[st->mmap_idx] = st->mmap_cur = buf; st->mmap_idx = (st->mmap_idx + 1) & (ARRAY_SIZE(st->mmaps) - 1); st->file_pos = st->file_offset + st->head; + return 0; +} + +static int +reader__process_events(struct reader *rd, struct perf_session *session, + struct ui_progress *prog) +{ + struct reader_state *st = &rd->state; + u64 size; + int err = 0; + union perf_event *event; + s64 skip; + +remap: + err = reader__mmap(rd, session); + if (err) + goto out; if (session->one_mmap) { - session->one_mmap_addr = buf; - session->one_mmap_offset = st->file_offset; + session->one_mmap_addr = rd->state.mmap_cur; + session->one_mmap_offset = rd->state.file_offset; } more: @@ -2285,17 +2304,8 @@ reader__process_events(struct reader *rd, struct perf_session *session, if (IS_ERR(event)) return PTR_ERR(event); - if (!event) { - if (mmaps[st->mmap_idx]) { - munmap(mmaps[st->mmap_idx], st->mmap_size); - mmaps[st->mmap_idx] = NULL; - } - - page_offset = page_size * (st->head / page_size); - st->file_offset += page_offset; - st->head -= page_offset; + if (!event) goto remap; - } session->active_reader = rd; size = event->header.size; -- 2.19.0
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