aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorIan Rogers <[email protected]>2023-05-26 20:43:22 -0700
committerArnaldo Carvalho de Melo <[email protected]>2023-06-12 18:18:14 -0300
commit892d00fba18a6dec2620165ce05e1697496f8381 (patch)
tree8ecb3d6d45b382f274dedf6732b17a4d1cfac8a8
parentd3944f0ed4e4039201b160fc11004abaa2ca5385 (diff)
perf inject: Lazily allocate guest_event event_buf
The event_buf is 64kb (PERF_SAMPLE_SIZE_MAX) and stack allocated in struct perf_inject. It is used for guest events that may not exist in a file. Make the array allocation lazy to cut down on the stack usage. Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
-rw-r--r--tools/perf/builtin-inject.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 2023b7a0daa6..c8cf2fdd9cff 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -47,7 +47,7 @@
struct guest_event {
struct perf_sample sample;
union perf_event *event;
- char event_buf[PERF_SAMPLE_MAX_SIZE];
+ char *event_buf;
};
struct guest_id {
@@ -1374,11 +1374,19 @@ static void guest_session__convert_time(struct guest_session *gs, u64 guest_time
static int guest_session__fetch(struct guest_session *gs)
{
- void *buf = gs->ev.event_buf;
- struct perf_event_header *hdr = buf;
+ void *buf;
+ struct perf_event_header *hdr;
size_t hdr_sz = sizeof(*hdr);
ssize_t ret;
+ buf = gs->ev.event_buf;
+ if (!buf) {
+ buf = malloc(PERF_SAMPLE_MAX_SIZE);
+ if (!buf)
+ return -ENOMEM;
+ gs->ev.event_buf = buf;
+ }
+ hdr = buf;
ret = readn(gs->tmp_fd, buf, hdr_sz);
if (ret < 0)
return ret;
@@ -2401,5 +2409,6 @@ out_close_output:
perf_data__close(&inject.output);
free(inject.itrace_synth_opts.vm_tm_corr_args);
free(inject.event_copy);
+ free(inject.guest_session.ev.event_buf);
return ret;
}