From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/3327 Path: news.gmane.org!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: cpuset/affinity interfaces and TSX lock elision in musl Date: Fri, 17 May 2013 13:28:02 +0200 Message-ID: <20130517112802.GA6699@port70.net> References: <20130516203658.GW20323@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1368790098 13633 80.91.229.3 (17 May 2013 11:28:18 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 17 May 2013 11:28:18 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-3331-gllmg-musl=m.gmane.org@lists.openwall.com Fri May 17 13:28:19 2013 Return-path: Envelope-to: gllmg-musl@plane.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1UdIpe-0003rY-TT for gllmg-musl@plane.gmane.org; Fri, 17 May 2013 13:28:19 +0200 Original-Received: (qmail 11288 invoked by uid 550); 17 May 2013 11:28:17 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 11270 invoked from network); 17 May 2013 11:28:14 -0000 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Xref: news.gmane.org gmane.linux.lib.musl.general:3327 Archived-At: * Daniel Cegie?ka [2013-05-17 09:41:18 +0200]: > >> 2) The upcoming glibc will have support for TSX lock elision. > >> > >> http://en.wikipedia.org/wiki/Transactional_Synchronization_Extensions > >> > >> http://lwn.net/Articles/534761/ > >> > >> Are there any outlook that we can support TSX lock elision in musl? > > > > I was involved in the discussions about lock elision on the glibc > > mailing list, and from what I could gather, it's a pain to implement > > and whether it brings you any benefit is questionable. > > There is currently no hardware support, so the tests were done in the > emulator. It's too early to say there's is no performance gain. > it's not the lock performance that's questionable but the benefits locks should not be the bottleneck in applications unless there is too much shared state on hot paths, which is probably a design bug or a special use-case for which non-standard synchronization methods may be better anyway for the implementation costs check the glibc discussion where rich pointed out conformance issues in the original design http://article.gmane.org/gmane.comp.lib.glibc.alpha/29240