Date: Thu, 10 Jun 2004 10:11:39 -0400 From: Don Bowman <don@sandvine.com> To: 'Bruce Evans' <bde@zeta.org.au>, Don Bowman <don@sandvine.com> Cc: "'current@freebsd.org'" <current@FreeBSD.org> Subject: RE: kernel trap 19 with interrupts disabled Message-ID: <FE045D4D9F7AED4CBFF1B3B813C85337051D8F5C@mail.sandvine.com>
next in thread | raw e-mail | index | archive | help
From: Bruce Evans [mailto:bde@zeta.org.au] > ... NMI, output but no debugger, hang, patch to workaround ... I have applied the patch, and will await the next hang. Out of curiousity, why not use something like this, so the timeout is fixed in time, rather than a #? I used the tsc here. static int my_stop_cpus(u_int map) { unsigned long long end_ts = rdtsc() + 1ULL * tsc_freq; /* send the Xcpustop IPI to all CPUs in map */ selected_apic_ipi(map, XCPUSTOP_OFFSET, APIC_DELMODE_FIXED); while ((stopped_cpus & map) != map) { /* Wait 1 second */ if ( rdtsc() > end_ts ) return 0; } return 1; } Has anyone else been observing system hangs with SMP Xeon (P4-based Xeon)? I have been observing this for more than a year with 4.7. We came up with a workaround by having a periodic NMI from the perfmon registers, and having it check for hardclock still incrementing. The problem we found is that hardclock would stop. I was hoping it was a race condition in the stable kernel, but now that i see what is most likely the same issue on current, i'm starting to wonder. I have a dual p3 system which has never experienced this problem. --don
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?FE045D4D9F7AED4CBFF1B3B813C85337051D8F5C>