[PATCH v6 16/20] perf session: Introduce decompressor into trace reader object

From: Alexey Bayduraev
Date: Wed May 26 2021 - 06:55:13 EST


Introduce decompressor into trace reader object so that decompression
could be executed on per data file basis separately for every data
file located in data directory.

Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@xxxxxxxxxxxxxxx>
---
tools/perf/util/session.c | 51 +++++++++++++++++++++++++++++----------
tools/perf/util/session.h | 1 +
2 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 335c073bae87..6c9a682eb291 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -73,6 +73,9 @@ struct reader {
u64 data_offset;
reader_cb_t process;
bool in_place_update;
+ struct zstd_data zstd_data;
+ struct decomp *decomp;
+ struct decomp *decomp_last;
struct reader_state state;
};

@@ -85,7 +88,10 @@ static int perf_session__process_compressed_event(struct perf_session *session,
size_t decomp_size, src_size;
u64 decomp_last_rem = 0;
size_t mmap_len, decomp_len = session->header.env.comp_mmap_len;
- struct decomp *decomp, *decomp_last = session->decomp_last;
+ struct decomp *decomp, *decomp_last = session->active_reader ?
+ session->active_reader->decomp_last : session->decomp_last;
+ struct zstd_data *zstd_data = session->active_reader ?
+ &session->active_reader->zstd_data : &session->zstd_data;

if (decomp_last) {
decomp_last_rem = decomp_last->size - decomp_last->head;
@@ -113,7 +119,7 @@ static int perf_session__process_compressed_event(struct perf_session *session,
src = (void *)event + sizeof(struct perf_record_compressed);
src_size = event->pack.header.size - sizeof(struct perf_record_compressed);

- decomp_size = zstd_decompress_stream(&(session->zstd_data), src, src_size,
+ decomp_size = zstd_decompress_stream(zstd_data, src, src_size,
&(decomp->data[decomp_last_rem]), decomp_len - decomp_last_rem);
if (!decomp_size) {
munmap(decomp, mmap_len);
@@ -123,12 +129,22 @@ static int perf_session__process_compressed_event(struct perf_session *session,

decomp->size += decomp_size;

- if (session->decomp == NULL) {
- session->decomp = decomp;
- session->decomp_last = decomp;
+ if (session->active_reader) {
+ if (session->active_reader->decomp == NULL) {
+ session->active_reader->decomp = decomp;
+ session->active_reader->decomp_last = decomp;
+ } else {
+ session->active_reader->decomp_last->next = decomp;
+ session->active_reader->decomp_last = decomp;
+ }
} else {
- session->decomp_last->next = decomp;
- session->decomp_last = decomp;
+ if (session->decomp == NULL) {
+ session->decomp = decomp;
+ session->decomp_last = decomp;
+ } else {
+ session->decomp_last->next = decomp;
+ session->decomp_last = decomp;
+ }
}

pr_debug("decomp (B): %zd to %zd\n", src_size, decomp_size);
@@ -319,11 +335,10 @@ static void perf_session__delete_threads(struct perf_session *session)
machine__delete_threads(&session->machines.host);
}

-static void perf_session__release_decomp_events(struct perf_session *session)
+static void perf_decomp__release_events(struct decomp *next)
{
- struct decomp *next, *decomp;
+ struct decomp *decomp;
size_t mmap_len;
- next = session->decomp;
do {
decomp = next;
if (decomp == NULL)
@@ -336,6 +351,8 @@ static void perf_session__release_decomp_events(struct perf_session *session)

void perf_session__delete(struct perf_session *session)
{
+ int r;
+
if (session == NULL)
return;
auxtrace__free(session);
@@ -343,10 +360,12 @@ void perf_session__delete(struct perf_session *session)
perf_session__destroy_kernel_maps(session);
perf_session__delete_threads(session);
if (session->readers) {
+ for (r = 0; r < session->nr_readers; r++)
+ perf_decomp__release_events(session->readers[r].decomp);
zfree(&session->readers);
session->nr_readers = 0;
}
- perf_session__release_decomp_events(session);
+ perf_decomp__release_events(session->decomp);
perf_env__exit(&session->header.env);
machines__exit(&session->machines);
if (session->data)
@@ -2157,7 +2176,8 @@ static int __perf_session__process_decomp_events(struct perf_session *session)
{
s64 skip;
u64 size;
- struct decomp *decomp = session->decomp_last;
+ struct decomp *decomp = session->active_reader ?
+ session->active_reader->decomp_last : session->decomp_last;

if (!decomp)
return 0;
@@ -2214,6 +2234,9 @@ reader__process_events(struct reader *rd, struct perf_session *session,

memset(mmaps, 0, sizeof(st->mmaps));

+ if (zstd_init(&rd->zstd_data, 0))
+ return -1;
+
mmap_prot = PROT_READ;
mmap_flags = MAP_SHARED;

@@ -2257,12 +2280,13 @@ reader__process_events(struct reader *rd, struct perf_session *session,
goto remap;
}

+ session->active_reader = rd;
size = event->header.size;

skip = -EINVAL;

if (size < sizeof(struct perf_event_header) ||
- (skip = rd->process(session, event, st->file_pos, rd->path)) < 0) {
+ (skip = perf_session__process_event(session, event, st->file_pos, rd->path)) < 0) {
pr_err("%#" PRIx64 " [%s] [%#x]: failed to process type: %d [%s]\n",
st->file_offset + st->head, rd->path, event->header.size,
event->header.type, strerror(-skip));
@@ -2289,6 +2313,7 @@ reader__process_events(struct reader *rd, struct perf_session *session,
goto more;

out:
+ session->active_reader = NULL;
return err;
}

diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 2815d00b5467..e0a8712f8770 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -44,6 +44,7 @@ struct perf_session {
struct decomp *decomp_last;
struct reader *readers;
int nr_readers;
+ struct reader *active_reader;
};

struct decomp {
--
2.19.0