Re: [PATCH] perf record: handle death by SIGTERM

From: David Ahern
Date: Tue May 07 2013 - 16:56:26 EST


On 5/7/13 12:29 AM, Ingo Molnar wrote:

* Stephane Eranian <eranian@xxxxxxxxxx> wrote:

This is a good fix. I have run into this infinite loop in perf report
many times.

Hm, perf record should really not assume much about the perf.data and
should avoid infinite loops ...

So while making perf.data more consistent on SIGTERM is a nice fix, perf
report should be fixed as well to detect loops and such.

Thanks,

Ingo


This seems to do the trick:

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 326068a..e82646f 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2802,6 +2802,17 @@ int perf_session__read_header(struct perf_session *session, int fd)
if (perf_file_header__read(&f_header, header, fd) < 0)
return -EINVAL;

+ /*
+ * sanity check that perf.data was written cleanly: data size
+ * is initialized to 0 and updated only if the on_exit function
+ * is run. If data size is still 0 then the file cannot be
+ * processed.
+ */
+ if (f_header.data.size == 0) {
+ pr_err("data size is 0. Was record properly terminated?\n");
+ return -1;
+ }
+
nr_attrs = f_header.attrs.size / f_header.attr_size;
lseek(fd, f_header.attrs.offset, SEEK_SET);

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