From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6064 invoked by alias); 6 Sep 2014 17:35:40 -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 6010 invoked by uid 48); 6 Sep 2014 17:35:28 -0000 From: "carlos at redhat dot com" To: glibc-bugs@sourceware.org Subject: [Bug nptl/17351] No hardware with functional lock elision available Date: Sat, 06 Sep 2014 17:35:00 -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: normal X-Bugzilla-Who: carlos at redhat 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: security- 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: 2014-09/txt/msg00036.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=17351 --- Comment #5 from Carlos O'Donell --- (In reply to Cedric BAIL from comment #4) > Checking the CPU RTM bit is not enough for application, they also need to > check the microcode version (This is the reason why glibc is turning on > elision when it should not use it in my opinion). You misunderstand. We will not protect you from faulty hardware. The choice is up to the user to apply the microcode update or not. It is *after* the microcode update that the RTM-enabled CPU with errata will have the RTM bit disabled, and therefore glibc will not use elision. On RTM-enabled CPUs that don't have the errata the RTM bit will be enabled and glibc will use elision. The library will not attempt to check the microcode version to disable elision, that is the responsibility of the user. All I was clarifying was that after the microcode update the library does the right thing. -- You are receiving this mail because: You are on the CC list for the bug.