From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16082 invoked by alias); 8 Nov 2019 16:22:40 -0000 Mailing-List: contact elfutils-devel-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: elfutils-devel-owner@sourceware.org Received: (qmail 16012 invoked by uid 89); 8 Nov 2019 16:22:39 -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=-6.5 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.1 spammy= X-Spam-Status: No, score=-6.5 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: gnu.wildebeest.org Received: from wildebeest.demon.nl (HELO gnu.wildebeest.org) (212.238.236.112) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 08 Nov 2019 16:22:38 +0000 Received: from tarox.wildebeest.org (tarox.wildebeest.org [172.31.17.39]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by gnu.wildebeest.org (Postfix) with ESMTPSA id 4030530014AB; Fri, 8 Nov 2019 17:22:36 +0100 (CET) Received: by tarox.wildebeest.org (Postfix, from userid 1000) id 39C2940006C6; Fri, 8 Nov 2019 17:22:36 +0100 (CET) Message-ID: <9caa7eee4a810e3f26cb2cb4ec4046e15d7dad4e.camel@klomp.org> Subject: Re: [PATCH 2/2] libdw: Rewrite the memory handler to be more robust. From: Mark Wielaard To: Jonathon Anderson Cc: elfutils-devel@sourceware.org Date: Fri, 08 Nov 2019 16:22:00 -0000 In-Reply-To: <1573152030.2173.2@rice.edu> References: <1572380520.19948.0@rice.edu> <20191029211437.3268-1-mark@klomp.org> <20191029211437.3268-2-mark@klomp.org> <93a4d8983b6ec43c09c6c3b3f6ed8d358321bb9d.camel@klomp.org> <1573152030.2173.2@rice.edu> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Mailer: Evolution 3.28.5 (3.28.5-5.el7) Mime-Version: 1.0 X-Spam-Flag: NO X-IsSubscribed: yes X-SW-Source: 2019-q4/txt/msg00117.txt.bz2 On Thu, 2019-11-07 at 12:40 -0600, Jonathon Anderson wrote: > I haven't benchmarked this version, but I did benchmark the equivalent=20 > earlier version (this version is almost quite literally a rebase of the=20 > other). I don't have the exact results on hand, what I remember is that=20 > the pthread_key method was faster (and handled the many-thread case=20 > better), by maybe a factor of 1.5x-2x in parallel. In serial the=20 > overhead was minimal (just an extra pointer indirection on allocations). I just tested the single-threaded case a bit and is not measurable slower than the previous version, and compared to 0.177 things are maybe ~1% slower (so probably in the noise). A factor 1.5x-2.0x slower in parallel does seem significant. Is that in the case of many-threads that are colliding a lot or in general? Thanks, Mark