From 613d8602292165f86ba1969784fea01a06d55900 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 15 Jun 2009 08:17:12 +0200 Subject: [PATCH] perf record: Fix fast task-exit race Recording with -a (or with -p) can race with tasks going away: couldn't open /proc/8440/maps Causing an early exit() and no recording done. Do not abort the recording session - instead just skip that task. Also, only print the warnings under -v. Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo LKML-Reference: Signed-off-by: Ingo Molnar --- tools/perf/builtin-record.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index a177a591b52c..e1dfef24887f 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -202,8 +202,12 @@ static void pid_synthesize_comm_event(pid_t pid, int full) fd = open(filename, O_RDONLY); if (fd < 0) { - fprintf(stderr, "couldn't open %s\n", filename); - exit(EXIT_FAILURE); + /* + * We raced with a task exiting - just return: + */ + if (verbose) + fprintf(stderr, "couldn't open %s\n", filename); + return; } if (read(fd, bf, sizeof(bf)) < 0) { fprintf(stderr, "couldn't read %s\n", filename); @@ -273,8 +277,12 @@ static void pid_synthesize_mmap_samples(pid_t pid) fp = fopen(filename, "r"); if (fp == NULL) { - fprintf(stderr, "couldn't open %s\n", filename); - exit(EXIT_FAILURE); + /* + * We raced with a task exiting - just return: + */ + if (verbose) + fprintf(stderr, "couldn't open %s\n", filename); + return; } while (1) { char bf[BUFSIZ], *pbf = bf; -- 2.20.1