From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11701 invoked by alias); 25 Aug 2007 05:39:13 -0000 Received: (qmail 6682 invoked by uid 48); 25 Aug 2007 05:38:58 -0000 Date: Sat, 25 Aug 2007 05:39:00 -0000 Message-ID: <20070825053858.6677.qmail@sourceware.org> From: "drepper at redhat dot com" To: glibc-bugs@sources.redhat.com In-Reply-To: <20070325101629.4274.bart.vanassche@gmail.com> References: <20070325101629.4274.bart.vanassche@gmail.com> Reply-To: sourceware-bugzilla@sourceware.org Subject: [Bug nptl/4274] Performance issue: pthread_cond_signal() causes three context switches instead of one X-Bugzilla-Reason: CC 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 X-SW-Source: 2007-08/txt/msg00107.txt.bz2 ------- Additional Comments From drepper at redhat dot com 2007-08-25 05:38 ------- Whatever you think you are measuring has nothing to do with glibc. Should there actually be extra wake-ups this happens entirely in the kernel. glibc uses FUTEX_WAKE_OP which prevents unnecessary delays. If the kernel schedules freshly woken threads right away before finishing the futex call something of course can go wrong. But all this happens in the kernel. glibc gives the kernel all the information it needs to avoid any problem. Talk to the kernel people. -- What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |WONTFIX http://sourceware.org/bugzilla/show_bug.cgi?id=4274 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.