From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-op-o12.zoho.com (sender4-op-o12.zoho.com [136.143.188.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A16452877C3 for ; Mon, 2 Mar 2026 18:02:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.12 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772474565; cv=pass; b=fJMtRoX71szazBx8v5/JtqLzHJxcEBBLLPQvo6f/NgdEev/kaRX2KjJ1vBmQFyArLx+GYq3ZqmWImC4LRrXuhVpGBYSqOKAIy41r4s9e0RG22g5bdXrR3tMw0UgfK65WSvj1pS1Ho8kWoo9nANvRJDHJxF1qUZisjkR3CKm22dI= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772474565; c=relaxed/simple; bh=AwEVLKt7BNikP1VvLGDFzAsBpswApdRWshH3CULE3Cs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=pt2mQAvyOOPU9l3fQw26QvhyD7rwZ7FnMkvv9NyDBAi23RCpjyNMrdSzsGhuL9/Qn1NR4KthWpGkxpANLUMPZwcRVowEHk8vdoIx6nGxehZcQ+Q3kZcyXtdmIxSiadc+a+FQW97MATVHVIDbwc+E8ig4nupOhhrMJoYfG4TZmSw= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=adrian.ratiu@collabora.com header.b=Mvl9mZEJ; arc=pass smtp.client-ip=136.143.188.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=adrian.ratiu@collabora.com header.b="Mvl9mZEJ" ARC-Seal: i=1; a=rsa-sha256; t=1772474556; cv=none; d=zohomail.com; s=zohoarc; b=gebU6PKDXOl2Dnf6sJjy86EO4mG4YczKycQlzjfEPTnP/0pIiSBFANZZBia85YMwjZqjKCTmLSYHLlGADcE0v8OhZnym/qfDcJe78uVhhUZIeF5B73/u0PoeQKmIw1uObiRshNJSQCCbMLAff8kGYcFy1CIi9rxnewmmuGfkkpI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1772474556; h=Content-Type:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=97bHlU+UJl5b6VHD35KS5GbSCdGZGoXAKdHp4TR9mGw=; b=MTDT9NCSzGSwKjQWCK9uAji+0vG0BjWL7n6iKY5G+KV+CJUYqm526DPpqR9BqEPfyLqx2FrKOEi3T4r/HU/oYwYorHBRM2i/12IfEHYcBSVW6PxXg+m0zNDQNOpsyw3cYIR9xyByEVgiVLRLHe4gbUJxwgInTrAVfgOq7K40r3k= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=adrian.ratiu@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1772474556; s=zohomail; d=collabora.com; i=adrian.ratiu@collabora.com; h=From:From:To:To:Cc:Cc:Subject:Subject:In-Reply-To:References:Date:Date:Message-ID:MIME-Version:Content-Type:Message-Id:Reply-To; bh=97bHlU+UJl5b6VHD35KS5GbSCdGZGoXAKdHp4TR9mGw=; b=Mvl9mZEJRLQxcplTLteiLUOdr0LXDW+XEGE/Tbf+4IayXOMM788BWOWvvPL4+ZTr 0WDPwHN0psFLfTLSZIH179mlFTQ0bOmyPDZ/x8PGjhry1TGN3GqnX3rxjdvLbdkkz+/ 39UvMCEWlOvKsgVV/JTEQGMEQRp97mWyFHw0nKis= Received: by mx.zohomail.com with SMTPS id 1772474554846746.6820625080604; Mon, 2 Mar 2026 10:02:34 -0800 (PST) From: Adrian Ratiu To: Jeff King , Patrick Steinhardt Cc: git@vger.kernel.org Subject: Re: Performance regression in "update" hooks In-Reply-To: <20260302175052.GA28275@coredump.intra.peff.net> References: <87bjh673o0.fsf@gentoo.mail-host-address-is-not-set> <874imy7220.fsf@collabora.com> <20260302175052.GA28275@coredump.intra.peff.net> Date: Mon, 02 Mar 2026 20:02:31 +0200 Message-ID: <87wlzu5cug.fsf@collabora.com> Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-ZohoMailClient: External 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. :)