From: Adrian Ratiu Date: Mon, 02 Mar 2026 18:02:31 GMT Subject: Re: Performance regression in "update" hooks Message-ID: <87wlzu5cug.fsf@collabora.com> In-Reply-To: <20260302175052.GA28275@coredump.intra.peff.net> On Mon, 02 Mar 2026, Jeff King wrote: > On Mon, Mar 02, 2026 at 03:27:22PM +0100, Patrick Steinhardt wrote: > >> > > I don't have the benchmark setup and it might be easier for you to >> > > confirm? >> >> All you need is a normal development infra and hyperfine. The >> benchmarking scripts in the repo I linked should then "just work" with >> the above invocation. > > Thanks, these were very cool and easy to use. > > Looking at the patch, my guess was that the problem is that we are now > setting up and tearing down the sideband muxer for each hook invocation. > This is expensive for the "update" hook, since it fires once per ref. I independently root caused it and came up with (mostly) the same fix, so this is a very good confirmation, thanks! Please wait for my patch because it needs fixing it 3 places, for 3 hooks which spin up/down no-op async threads. :)