From 0c1d46a8796e8309f1ca693e5cad6f318e4b8159 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 20 Apr 2016 18:59:52 +0000 Subject: perf record: Disable buildid cache options by default in switch output mode The cost of buildid cache processing is high: reading all events in output perf.data, opening each elf file to read buildids then copying them into ~/.debug directory. In switch output mode, these heavy works block perf from receiving perf events for too long. Enable no-buildid and no-buildid-cache by default if --switch-output is provided. Still allow user use --no-no-buildid to explicitly enable buildid in this case. Signed-off-by: Wang Nan Cc: Adrian Hunter Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1461178794-40467-6-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang [ Updated man page ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-record.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/perf/Documentation') diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 79a8a14f37b1..8dbee832abd9 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -358,7 +358,7 @@ A possible use case is to, given an external event, slice the perf.data file that gets then processed, possibly via a perf script, to decide if that particular perf.data snapshot should be kept or not. -Implies --timestamp-filename. +Implies --timestamp-filename, --no-buildid and --no-buildid-cache. SEE ALSO -------- -- cgit v1.2.3