From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hedi Berriche Date: Fri, 27 Aug 2010 14:52:31 +0000 Subject: Re: Serious problem with ticket spinlocks on ia64 Message-Id: <20100827145231.GZ18967@zorg.emea.sgi.com> List-Id: References: <201008271537.35709.ptesarik@suse.cz> <201008271609.16099.ptesarik@suse.cz> <20100827143135.GY18967@zorg.emea.sgi.com> <201008271640.49542.ptesarik@suse.cz> In-Reply-To: <201008271640.49542.ptesarik@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Petr Tesarik Cc: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, Tony Luck On Fri, Aug 27, 2010 at 15:40 Petr Tesarik wrote: | On Friday 27 of August 2010 16:31:35 Hedi Berriche wrote: | | > That said, I'm letting my already over 36 hours run carry on chewing CPU | > time, and see if it will eventually trip the same problem seen with 4-byte | > ticket locks. | | Hm, this doesn't sound like a viable approach. Since the siglock gets | initialized to 0 when a new process is started, it may never actually wrap | around. | | I would rather attach a SystemTap probe somewhere during process fork and add | a bias to the siglock. That should work fine. Let me knock up the SystemTap | script... That would be nice. Ta! Cheers, Hedi. -- Hedi Berriche Global Product Support http://www.sgi.com/support