From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14623 invoked by alias); 27 Feb 2009 22:16:46 -0000 Received: (qmail 14584 invoked by uid 48); 27 Feb 2009 22:16:36 -0000 Date: Sat, 28 Feb 2009 02:04:00 -0000 Message-ID: <20090227221636.14583.qmail@sourceware.org> From: "mhiramat at redhat dot com" To: systemtap@sources.redhat.com In-Reply-To: <20081001203800.6932.mhiramat@redhat.com> References: <20081001203800.6932.mhiramat@redhat.com> Reply-To: sourceware-bugzilla@sourceware.org Subject: [Bug translator/6932] c->busy can be non-atomic. X-Bugzilla-Reason: AssignedTo Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2009-q1/txt/msg00554.txt.bz2 ------- Additional Comments From mhiramat at redhat dot com 2009-02-27 22:16 ------- (In reply to comment #10) > (In reply to comment #9) > > Created an attachment (id=3782) --> (http://sourceware.org/bugzilla/attachment.cgi?id=3782&action=view) > > [PATCH] make busy nonatomic > > It should be fine to make this non-atomic, but I think it needs barriers to > preserve memory order. Otherwise the compiler/architecture could reorder the > writes into the context pointer. It might turn into: > > 1. write some c->fields > >>> interrupt with a probe -> step #1 is overwritten > 2. write c->busy = 1 > 3. write more c->fields, run the probe, etc. Oops, right. Thank you for pointing it out! I'll update it. -- http://sourceware.org/bugzilla/show_bug.cgi?id=6932 ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee.