Date: Thu, 23 Jan 2003 09:58:09 +0000 From: Doug Rabson <dfr@nlsystems.com> To: Arun Sharma <adsharma@unix-os.sc.intel.com> Cc: freebsd-ia64@FreeBSD.ORG Subject: Re: cat /proc/pid/map == panic Message-ID: <200301230958.09691.dfr@nlsystems.com> In-Reply-To: <20030122142309.A15191@unix-os.sc.intel.com> References: <200301220302.h0M323r01126@unix-os.sc.intel.com> <200301221021.29297.dfr@nlsystems.com> <20030122142309.A15191@unix-os.sc.intel.com>
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On Wednesday 22 January 2003 10:23 pm, Arun Sharma wrote: > On Wed, Jan 22, 2003 at 10:21:29AM +0000, Doug Rabson wrote: > > On Wednesday 22 January 2003 3:02 am, Arun Sharma wrote: > > > cat /proc/pid/map results in a page not present fault. The > > > attached patch fixed it for me. > > > > This is going to find the wrong pte, I think. Without the > > pmap_install(pmap), your pmap_find_vhpt will look in the current > > process instead of the target. > > That's right. An updated patch is attached. It looks right to me. Do you have a commit bit? Shall I commit the fix? > > > Does it work if you just add the check > > for pmap=3D=3D0 to the old code, i.e. still use pmap_install and tpa = to > > get the mapping? > > I haven't tried it, but I think in my case pmap was almost certainly > non-zero (the process in question is sshd). Further, cr.iip was > pointing to the tpa instruction when the page not present fault > happened. The problem with ia64_tpa is that it will result in faults. > The code in procfs is trying to count the number of resident pages - > so you may not want to fault more pages in. Oh, of course. It makes much more sense now. > > A further optimization of this patch may be to just load one region > register instead of loading all of them. I guess that depends how expensive the generic pmap_install actually is.=20 It would be pretty interesting to know the costs of e.g. loading a=20 region register, loading a translation register etc. --=20 Doug Rabson=09=09=09=09Mail: dfr@nlsystems.com =09=09=09=09=09Phone: +44 20 8348 6160 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-ia64" in the body of the message
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