From 887fa86d6fd7a45cee2d0f9d5f75026786d61df2 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 5 Aug 2016 12:37:21 -0300 Subject: [PATCH] perf hists: Trim libtraceevent trace_seq buffers When we use libtraceevent to format trace event fields into printable strings to use in hist entries it is important to trim it from the default 4 KiB it starts with to what is really used, to reduce the memory footprint, so use realloc(seq.buffer, seq.len + 1) when returning the seq.buffer formatted with the fields contents. Reported-and-Tested-by: Wang Nan Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lkml.kernel.org/n/tip-t3hl7uxmilrkigzmc90rlhk2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/sort.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c index 947d21f38398..3d3cb8392c86 100644 --- a/tools/perf/util/sort.c +++ b/tools/perf/util/sort.c @@ -588,7 +588,11 @@ static char *get_trace_output(struct hist_entry *he) } else { pevent_event_info(&seq, evsel->tp_format, &rec); } - return seq.buffer; + /* + * Trim the buffer, it starts at 4KB and we're not going to + * add anything more to this buffer. + */ + return realloc(seq.buffer, seq.len + 1); } static int64_t