From 8c3e05c827ef687215723680862ebd2d431dee49 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 21 May 2020 19:09:14 -0700 Subject: [PATCH] perf script: Don't force less for non tty output with --xed --xed currently forces less. When piping the output to other scripts this can waste a lot of CPU time because less is rather slow. I've seen it using up a full core on its own in a pipeline. Only force less when the output is actually a terminal. Signed-off-by: Andi Kleen Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20200522020914.527564-1-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-script.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 4c0837efaceb..2810d5a7096b 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -3301,7 +3301,10 @@ static int parse_xed(const struct option *opt __maybe_unused, const char *str __maybe_unused, int unset __maybe_unused) { - force_pager("xed -F insn: -A -64 | less"); + if (isatty(1)) + force_pager("xed -F insn: -A -64 | less"); + else + force_pager("xed -F insn: -A -64"); return 0; }