From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: [patch 18/20] clean up tsc-based sched_clock Date: Fri, 06 Apr 2007 16:27:20 -0700 Message-ID: <4616D758.6020300@goop.org> References: <20070404191151.009821039@goop.org> <20070404191206.476822257@goop.org> <20070406162233.b835bd4c.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20070406162233.b835bd4c.akpm@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton Cc: Andi Kleen , virtualization@lists.osdl.org, lkml List-Id: virtualization@lists.linuxfoundation.org Andrew Morton wrote: > On Wed, 04 Apr 2007 12:12:09 -0700 Jeremy Fitzhardinge wrote: > > >> Three cleanups: >> - change "instable" -> "unstable" >> - its better to use get_cpu_var for getting this cpu's variables >> - change cycles_2_ns to do the full computation rather than just the >> tsc->ns scaling. Its a simpler interface, and it makes the function >> more generally useful. >> >> Signed-off-by: Jeremy Fitzhardinge >> >> --- >> arch/i386/kernel/sched-clock.c | 35 +++++++++++++++++++++-------------- >> > > I'm dropping the relevant patch from Andi's tree due to it causing > mysterious hangs when initscripts start ondemand. So I'll need to drop > this patch and "[patch 19/20] Add a sched_clock paravirt_op". > OK. That just means we need to go back to the original "Add a sched_clock paravirt_op" follow-on patch. > I still need to work out why that hang is happening - it is very > mysterious. I got as far as working out that it was hanging on > write_seqlock_irqsave(xtime_lock), then remembered that it's with > CONFIG_SMP=n so I stomped off to bed in disgust. Later. > Hangs always, or just sometimes? I haven't seen any problems with it. J