Date: Sun, 16 Nov 2003 17:34:36 -0800 From: Marcel Moolenaar <marcel@xcllnt.net> To: deischen@freebsd.org Cc: davidxu@freebsd.org Subject: Re: KSE/ia64 broken Message-ID: <20031117013436.GA61716@dhcp01.pn.xcllnt.net> In-Reply-To: <Pine.GSO.4.10.10311161951020.11563-100000@pcnet5.pcnet.com> References: <20031116222200.GA61279@dhcp01.pn.xcllnt.net> <Pine.GSO.4.10.10311161951020.11563-100000@pcnet5.pcnet.com>
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On Sun, Nov 16, 2003 at 07:54:24PM -0500, Daniel Eischen wrote: > On Sun, 16 Nov 2003, Marcel Moolenaar wrote: > > > On Sun, Nov 16, 2003 at 04:55:44PM -0500, Daniel Eischen wrote: > > > On Sun, 16 Nov 2003, Marcel Moolenaar wrote: > > > > > > > > The same thread (main thread) is being resumed over and over again > > > > > which shouldn't happen for this simple program. > > > > > > > > Can it be that the thread is deadlocked? There's no forward progress. > > > > There's only context switching... > > > > > > I don't think so. I think the thread stack/frame is corrupted, either > > > because it is copied out or resumed incorrectly. I'll do some more > > > digging. > > > > I loaded it up in the simulator. The thread is continuously being > > resumed because of a page fault that results in an upcall, which > > ends up in the UTS, which selects the same thread, which causes the > > page fault again. > > Is it possible the thread is marked for an upcall when the > page is not yet present? No, it's just a side-effect. The problem is that we get an upcall when we allocate struct pthread for the signal daemon. This is before we set the maximum concurrency. The upcall is what's causing problems, because previously the KSE lock prevented the upcall. I don't yet know what exactly is being messed up, but eventually we clobber memory. The clobbering invalidates pointerd and that's what's causing the page faults. Hence, the damage has been done before we get the SIGILL. > I'm not getting threads@ mail any longer, just the CC. Are > you? Yes, I get the threads@ mail. -- Marcel Moolenaar USPA: A-39004 marcel@xcllnt.net
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