From mboxrd@z Thu Jan 1 00:00:00 1970 From: Petr Tesarik Date: Fri, 27 Aug 2010 20:41:14 +0000 Subject: Re: Serious problem with ticket spinlocks on ia64 Message-Id: <201008272241.15735.ptesarik@suse.cz> List-Id: References: <201008271537.35709.ptesarik@suse.cz> <987664A83D2D224EAE907B061CE93D53015D91D029@orsmsx505.amr.corp.intel.com> <987664A83D2D224EAE907B061CE93D53015D91D3B7@orsmsx505.amr.corp.intel.com> In-Reply-To: <987664A83D2D224EAE907B061CE93D53015D91D3B7@orsmsx505.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Luck, Tony" Cc: "linux-ia64@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Hedi Berriche On Friday 27 of August 2010 22:29:41 Luck, Tony wrote: > > If this is a memory ordering problem (and that seems quite plausible) > > then a liberal sprinkling of "ia64_mf()" calls throughout the spinlock > > routines would probably make it go away. > > I think I take this back ... if it were a memory ordering problem, then > it could show up any time - not just at wrap-around. Well, I wasn't originally sure if it only happens at wrap-around. OTOH I've now modified my tests, so that they would also catch any other badness, and I still only got another two failures after wrap-around. >From looking at the traces, I'm afraid this smells like another Itanium erratum. I'm now trying to write a minimal test case... Petr Tesarik