Changes in v2:
- introduced struct decomp_data suggested by Jiri Olsa
- removed unnecessary [PATCH v1 1/6]
- removed unnecessary extra line in [PATCH v2 4/5]
- removed unnecessary reader_state.eof flag in [PATCH v2 5/5]
Patch set adds state info and decompressor object into reader object
that made possible to split reader__process_events function into three
logical parts: init/exit, map/unmap and single event reader which are
used in events reader loop. This approach allows reading multiple trace
files at the same time.
The design and implementation are based on the prototype [1], [2].
The patch set was separated from [3] and already was rewieved by
Namhyung Kim and Riccardo Mancini. The difference from [3] is that
this patch set keeps reader object allocation on the stack.
Tested:
tools/perf/perf record -o prof.data -- matrix.gcc.g.O3
tools/perf/perf record -o prof.data -z -- matrix.gcc.g.O3
tools/perf/perf report -i prof.data
tools/perf/perf report -i prof.data --call-graph=callee
tools/perf/perf report -i prof.data --stdio --header
tools/perf/perf report -i prof.data -D --header
[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/[email protected]/
[3] https://lore.kernel.org/lkml/[email protected]/
Alexey Bayduraev (5):
perf session: Introduce reader_state in reader object
perf session: Introduce decompressor in reader object
perf session: Move init/exit code to separate functions
perf session: Move map/unmap to separate function
perf session: Load single file for analysis
tools/perf/util/session.c | 215 +++++++++++++++++++++++++-------------
tools/perf/util/session.h | 10 +-
2 files changed, 151 insertions(+), 74 deletions(-)
--
2.19.0
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.
Suggested-by: Jiri Olsa <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Reviewed-by: Riccardo Mancini <[email protected]>
Tested-by: Riccardo Mancini <[email protected]>
Signed-off-by: Alexey Bayduraev <[email protected]>
---
tools/perf/util/session.c | 61 ++++++++++++++++++++++-----------------
1 file changed, 35 insertions(+), 26 deletions(-)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 53cd7a3b5efd..6c825e4a9dfe 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -2193,13 +2193,9 @@ static int
reader__init(struct reader *rd, bool *one_mmap)
{
struct reader_state *st = &rd->state;
- u64 page_offset;
char **mmaps = st->mmaps;
- 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;
st->mmap_size = MMAP_SIZE;
@@ -2226,15 +2222,12 @@ reader__exit(struct reader *rd)
}
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;
@@ -2245,20 +2238,45 @@ 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:
@@ -2267,17 +2285,8 @@ 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_decomp = &rd->decomp_data;
size = event->header.size;
--
2.19.0