From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11153 invoked by alias); 27 Nov 2019 12:52:41 -0000 Mailing-List: contact dwz-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: dwz-owner@sourceware.org Received: (qmail 11144 invoked by uid 89); 27 Nov 2019 12:52:41 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.100.3 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-6.0 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.1 spammy=HX-Languages-Length:1575, 32400, promising, vehicle X-Spam-Status: No, score=-6.0 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on sourceware.org X-Spam-Level: X-HELO: mx1.suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Subject: Re: [Highlight] Performance improvements To: Tom de Vries , dwz@sourceware.org, Jakub Jelinek , Mark Wielaard , Michael Matz References: From: =?UTF-8?Q?Martin_Li=c5=a1ka?= Message-ID: Date: Tue, 01 Jan 2019 00:00:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-SW-Source: 2019-q4/txt/msg00084.txt.bz2 On 11/26/19 6:59 PM, Tom de Vries wrote: > Hi, > > I've been working on performance improvements for dwz, using a cc1 > binary as my optimization vehicle. > > Comparing the situation: > - before (commit 04a676d Add --devel-partition-dups-opt), and > - after (current master, commit e405c62 Add --devel-die-count-method > {none,estimate}) > I get the following results. > > When avoiding running into the low-mem die-limit using -lnone, we get > ~25% performance improvement, due to an improved hash function and an > improved hash table allocation strategy (without increasing peak memory > usage): > ... > real: mean: 7378.10 100.00% stddev: 45.31 > mean: 5558.80 75.34% stddev: 35.18 > user: mean: 7106.30 100.00% stddev: 41.53 > mean: 5328.10 74.98% stddev: 22.33 > sys: mean: 271.60 100.00% stddev: 39.57 > mean: 230.00 84.68% stddev: 40.45 > ... > > And if we don't avoid running into the low-mem die-limit, we get ~38% > performance improvement: > ... > real: mean: 15084.80 100.00% stddev: 44.53 > mean: 9232.90 61.21% stddev: 41.80 > user: mean: 14759.40 100.00% stddev: 30.62 > mean: 9100.10 61.66% stddev: 41.75 > sys: mean: 324.00 100.00% stddev: 39.51 > mean: 132.00 40.74% stddev: 27.26 > ... > which is also paired with a reduction in peak memory usage of ~34%, from > 0.95GB to 0.63GB, due to running into the low-mem die-limit in a more > efficient manner. Hi. That sounds very promising! I would like to see it being used in our openSUSE package. Are you planning to use it? Thanks, Martin > > Thanks, > - Tom >