From a7c1c102562c141b752f06f94c99438fa80319e8 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 10 Jul 2024 04:35:13 -0400 Subject: [PATCH] chainlint.pl: only start threads if jobs > 1 If the system supports threads, chainlint.pl will always spawn worker threads to do the real work. But when --jobs=1, this is pointless, since we could just do the work in the main thread. And spawning even a single thread has a high overhead. For example, on my Linux system, running: for i in chainlint/*.test; do perl chainlint.pl --jobs=1 $i done >/dev/null takes ~1.7s without this patch, and ~1.1s after. We don't usually spawn a bunch of individual chainlint.pl processes (instead we feed several scripts at once, and the parallelism outweighs the setup cost). But it's something we've considered doing, and since we already have fallback code for systems without thread support, it's pretty easy to make this work. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- t/chainlint.pl | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/t/chainlint.pl b/t/chainlint.pl index 1bbd985b78..1864d048ae 100755 --- a/t/chainlint.pl +++ b/t/chainlint.pl @@ -807,7 +807,8 @@ unless (@scripts) { exit; } -unless ($Config{useithreads} && eval { +unless ($jobs > 1 && + $Config{useithreads} && eval { require threads; threads->import(); require Thread::Queue; Thread::Queue->import(); 1; -- 2.52.0