Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751112Ab0DMEGo (ORCPT ); Tue, 13 Apr 2010 00:06:44 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:52126 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750728Ab0DMEGn (ORCPT ); Tue, 13 Apr 2010 00:06:43 -0400 Subject: Re: [PATCH] time: remove xtime_cache (take 2) From: john stultz To: Andrew Morton Cc: lkml , Petr =?UTF-8?Q?Tit=C4=9Bra?= , Thomas Gleixner In-Reply-To: <20100412210044.2ebbc058.akpm@linux-foundation.org> References: <1270589451-30773-1-git-send-email-johnstul@us.ibm.com> <20100412210044.2ebbc058.akpm@linux-foundation.org> Content-Type: text/plain; charset="UTF-8" Date: Mon, 12 Apr 2010 21:06:40 -0700 Message-ID: <1271131600.3469.20.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1683 Lines: 46 On Mon, 2010-04-12 at 21:00 -0400, Andrew Morton wrote: > On Tue, 6 Apr 2010 14:30:51 -0700 John Stultz wrote: > > > Thomas: Mind queueing this up for 2.6.35? > > > > With the earlier logarithmic time accumulation patch, xtime will now > > always be within one "tick" of the current time, instead of possibly > > half a second off. > > > > This removes the need for the xtime_cache value, which always stored the > > time at the last interrupt, so this patch cleans that up removing the > > xtime_cache related code. > > > > This patch also addresses an issue with an earlier version of this change, > > where xtime_cache was normalizing xtime, which could in some cases be > > not valid (ie: tv_nsec == NSEC_PER_SEC). This is fixed by handling > > the edge case in update_wall_time(). > > > > ... > > > > --- a/kernel/time.c > > +++ b/kernel/time.c > > @@ -135,7 +135,6 @@ static inline void warp_clock(void) > > write_seqlock_irq(&xtime_lock); > > wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; > > xtime.tv_sec += sys_tz.tz_minuteswest * 60; > > - update_xtime_cache(0); > > write_sequnlock_irq(&xtime_lock); > > clock_was_set(); > > } > > This conflicts with your time-clean-up-warp_clock.patch, below. > > Shrug, I simply ignored the rejected hunk. Yep. That should be fine. We're just dropping the update_xtime_cache call, so if it doesn't exist, its not a problem. thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/