From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cloud.peff.net (cloud.peff.net [104.130.231.41]) (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 1CCB213D296 for ; Thu, 23 May 2024 10:54:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=104.130.231.41 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716461665; cv=none; b=lx5j3XHCf34qYiGQmYKXVNOzItYEbwn/f+f3cJqHS4H0E/KmCFP0DerJnTNz/2hZ6+SXwmj/MFlRvEmOFwHcPDOcGlPd2/Rc+i+QgOU5fCXzMZmyeKZ8FZEr+pM4Eyk3o7EpW96GLExFBlwqM8qiHaWZOuurgNkFFpCIz8MWpDs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716461665; c=relaxed/simple; bh=lQ+v3woZAgzk0TI+yofbVV0po3hgUF5WocUjv8+UHEU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=i2zh4oEop0S8Ps9ZNoruaA5rQZGeRUZJCt6n6Ogvr+rcQM6R5ntxGzaIGQpuTpS0/vvSOIky4bJ/po6/0WHRA8fMbWiSpV/S2Q3bihTY7nTwlLx2g1t/qsjouN1in6Rwvtb3N3lvBe8qVVcnB24qICzNok9XZDmpB5k3/nP3XAw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=peff.net; spf=pass smtp.mailfrom=peff.net; arc=none smtp.client-ip=104.130.231.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=peff.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=peff.net Received: (qmail 31379 invoked by uid 109); 23 May 2024 10:54:23 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with ESMTP; Thu, 23 May 2024 10:54:23 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 29340 invoked by uid 111); 23 May 2024 10:54:28 -0000 Received: from coredump.intra.peff.net (HELO coredump.intra.peff.net) (10.0.0.2) by peff.net (qpsmtpd/0.94) with (TLS_AES_256_GCM_SHA384 encrypted) ESMTPS; Thu, 23 May 2024 06:54:28 -0400 Authentication-Results: peff.net; auth=none Date: Thu, 23 May 2024 06:54:22 -0400 From: Jeff King To: Taylor Blau Cc: git@vger.kernel.org, Elijah Newren , Patrick Steinhardt , Junio C Hamano Subject: Re: [PATCH v3 30/30] t/perf: implement performace tests for pseudo-merge bitmaps Message-ID: <20240523105422.GF1308330@coredump.intra.peff.net> References: <6a6d88fa512ba344543f5f0df33d5a61e406f3db.1716318089.git.me@ttaylorr.com> Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <6a6d88fa512ba344543f5f0df33d5a61e406f3db.1716318089.git.me@ttaylorr.com> On Tue, May 21, 2024 at 03:03:17PM -0400, Taylor Blau wrote: > Implement a straightforward performance test demonstrating the benefit > of pseudo-merge bitmaps by measuring how long it takes to count > reachable objects in a few different scenarios: > > - without bitmaps, to demonstrate a reasonable baseline > - with bitmaps, but without pseudo-merges > - with bitmaps and pseudo-merges > > Results from running this test on git.git are as follows: > > Test this tree > ----------------------------------------------------------------------------------- > 5333.2: git rev-list --count --all --objects (no bitmaps) 3.46(3.37+0.09) > 5333.3: git rev-list --count --all --objects (no pseudo-merges) 0.13(0.11+0.01) > 5333.4: git rev-list --count --all --objects (with pseudo-merges) 0.12(0.11+0.01) That's not a very exciting result. I have a feeling that your git.git is not a very interesting test case. We'd want a lot of refs, and ones that are old and have bushy history that is not included in the more recent branches. So something like a bunch of old unmerged pull request heads, for example. ;) Do you have more interesting numbers for something like that? -Peff