From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Owens Date: Thu, 13 Mar 2003 22:42:41 +0000 Subject: [Linux-ia64] Re: ia64_spinlock_contention and NEW_LOCK 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, 13 Mar 2003 14:26:28 -0800, David Mosberger wrote: >>>>>> On Fri, 14 Mar 2003 09:20:12 +1100, Keith Owens said: > > Keith> I am not touching the real ar.pfs, precisely to avoid > Keith> changing leaf routines. Setting r29 to 0 and .save ar.pfs, > Keith> r29 in ia64_unwind_contention will fool the unwind code into > Keith> doing the unwind correctly but without changing the state of > Keith> the routine using spin_lock(). > >Ah, sorry, I didn't read your mail carefully enough. Hmmh, not >exactly a pretty solution, but I don't see anything obviously wrong >with it either. With libunwind, you could in fact say > > .save ar.pfs,r0 > >but I don't remember whether this would work with the kernel unwinder >(if it doesn't, it would be easy to fix though). I wanted to do .save ar.pfs,r0, but it needs a change to unw_access_gr(). As you say, easy enough to fix, but I wanted to minimize the changes for this new spinlock code. OTOH, if you do not mind changing unw_access_gr(), I will do it that way and free up r29.