From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15755 invoked by alias); 15 Jul 2013 21:35:48 -0000 Mailing-List: contact glibc-bugs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: glibc-bugs-owner@sourceware.org Received: (qmail 13107 invoked by uid 48); 15 Jul 2013 21:33:44 -0000 From: "adeb at nvidia dot com" To: glibc-bugs@sourceware.org Subject: [Bug nptl/15640] The ARM port of lll_unlock uses atomic compare and swap to release a lock Date: Mon, 15 Jul 2013 21:35:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: nptl X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: enhancement X-Bugzilla-Who: adeb at nvidia dot com X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-07/txt/msg00085.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=15640 --- Comment #2 from Abhishek Deb --- On second thoughts, I think what is required is an atomic_exchange_rel and not atomic_compare_and_exchange. Though lll_unlock uses atomic_exchange_rel, but because atomic_exchange_rel was never defined for ARM, it gets defined to atomic_compare_and_exhange_rel. I think atomic_exchange_rel could perhaps be implemented with a pair of ldex, stex and a branch if the atomic exchange failed. -- You are receiving this mail because: You are on the CC list for the bug.