From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Thu, 14 Dec 2000 06:21:49 +0000 Subject: Re: [Linux-ia64] switch_stack position Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On Thu, 14 Dec 2000 16:13:06 +1100, Keith Owens said: Keith> On Wed, 13 Dec 2000 20:39:17 -0800, David Mosberger Keith> wrote: >> Note that the unwind code is written such that it cannot fault, >> even if the initial state on the stack is completely bogus. This >> is why it's safe to call get_wchan() on a process that's running. Keith> Safe but it gives misleading results which confuse people Keith> doing debugging. I had the same problem on kdb for ia32. Keith> Doing backtrace of the running process on cpu 0 from cpu 1 Keith> (btp pid) gave different results compared to backtrace of the Keith> current process on cpu 0 (bt). Debuggers should not give Keith> different results for the same process just because you are Keith> looking from another cpu. Sure, kdb should do it's job right, but kdb is certainly no reason to to hack the context switch code. Not for something that 99.9% of the users never even know existed. --david