From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from puffin.external.hp.com (puffin.external.hp.com [192.25.206.4]) by dsl2.external.hp.com (Postfix) with ESMTP id 8C442482C for ; Thu, 29 Nov 2001 12:02:48 -0700 (MST) Received: from puffin (IDENT:grundler@localhost [127.0.0.1]) by puffin.external.hp.com (8.9.3/8.9.3) with ESMTP id LAA02339 for ; Thu, 29 Nov 2001 11:58:19 -0700 Message-Id: <200111291858.LAA02339@puffin.external.hp.com> To: parisc-linux@parisc-linux.org Subject: Re: [parisc-linux] travel backwards in time? In-Reply-To: Message from Randolph Chung of "Thu, 18 Oct 2001 13:21:45 PDT." <20011018132145.H4123@tausq.org> Date: Thu, 29 Nov 2001 11:58:19 -0700 From: Grant Grundler Sender: parisc-linux-admin@lists.parisc-linux.org Errors-To: parisc-linux-admin@lists.parisc-linux.org List-Help: List-Post: List-Subscribe: , List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: Randolph Chung wrote: > Recently Grant and I have observed several hangs in do_gettimeofday on a > c3k running 32 or 64-bit kernels (UP). > > The symptom we see is gettimeoffset returns a negative number which > results in a huge (unsigned) usec offset in do_gettimeofday, which ends > up spinning in a while loop. ... > The last_tick adjustment looks a bit odd. Looking at ia64, it looks more > like this: > > last_tick -= clocktick * (jiffies - wall_jiffies + 1); For the record, this fix was committed in one of the 2.4.14-pa5 http://lists.parisc-linux.org/pipermail/parisc-linux-cvs/2001-November/030021.html I'm still not 100% certain all our time keeping code is correct. But I'm comfortable this patch fixes the problem we saw and does not introduce any new ones. grant