diff options
| author | Ian Rogers <irogers@google.com> | 2025-02-21 22:10:10 -0800 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2025-02-24 15:46:33 -0800 |
| commit | 56406bd557fb928757cad53aea27e38c06e3f72b (patch) | |
| tree | 8ca5b9a3e7be78ff4e78f209d670c577e0e2d526 | |
| parent | d6cd7c9f0239b28652a7ca1870707f5ca6c49c9f (diff) | |
perf events: Remove scandir in thread synthesis
This avoids scanddir reading the directory into memory that's
allocated and instead allocates on the stack.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20250222061015.303622-6-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
| -rw-r--r-- | tools/perf/util/synthetic-events.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index 2dfc4260d36d..2fc4d0537840 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -38,6 +38,7 @@ #include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */ #include <api/fs/fs.h> #include <api/io.h> +#include <api/io_dir.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> @@ -767,10 +768,10 @@ static int __event__synthesize_thread(union perf_event *comm_event, bool needs_mmap, bool mmap_data) { char filename[PATH_MAX]; - struct dirent **dirent; + struct io_dir iod; + struct io_dirent64 *dent; pid_t tgid, ppid; int rc = 0; - int i, n; /* special case: only send one comm event using passed in pid */ if (!full) { @@ -802,16 +803,19 @@ static int __event__synthesize_thread(union perf_event *comm_event, snprintf(filename, sizeof(filename), "%s/proc/%d/task", machine->root_dir, pid); - n = scandir(filename, &dirent, filter_task, NULL); - if (n < 0) - return n; + io_dir__init(&iod, open(filename, O_CLOEXEC | O_DIRECTORY | O_RDONLY)); + if (iod.dirfd < 0) + return -1; - for (i = 0; i < n; i++) { + while ((dent = io_dir__readdir(&iod)) != NULL) { char *end; pid_t _pid; bool kernel_thread = false; - _pid = strtol(dirent[i]->d_name, &end, 10); + if (!isdigit(dent->d_name[0])) + continue; + + _pid = strtol(dent->d_name, &end, 10); if (*end) continue; @@ -845,9 +849,7 @@ static int __event__synthesize_thread(union perf_event *comm_event, } } - for (i = 0; i < n; i++) - zfree(&dirent[i]); - free(dirent); + close(iod.dirfd); return rc; } |