Marcelo Tosatti wrote: > On Mon, May 12, 2008 at 02:19:24PM -0500, Ryan Harper wrote: > > Hi Ryan, > > There are two places that attempt to use delivery mode 7: kexec crash > and io_apic_64.c::check_timer(). > > The later will happen if the guest fails to receive PIT IRQ's for 10 > ticks. If you're using HZ=1000 thats 10ms. See timer_irq_works(). > > The in-kernel pit emulation has logic which avoids injecting more than > one IRQ during 10ms. > > Note that the guest 10ms delay is TSC based and uses only the lower > 32-bits of the value. It is quite likely that the TSC adjustment results > in them increasing more rapidly then they should. >
Or that the TSC is terribly miscalibrated. Here is the log of all 48 guests. In this case, the host detects 1995.008 as the frequency. This is a Barcelona. I suspect that we're masking the X86_FEATURE_CONSTANT_TSC though. From a quick look, I suspect that the number of wildly off TSC calibrations correspond to the VMs that are misbehaving. I think this may mean that we have to re-examine the tsc delta computation. 10_serial.log:time.c: Detected 1995.038 MHz processor. 11_serial.log:time.c: Detected 2363.195 MHz processor. 12_serial.log:time.c: Detected 2492.675 MHz processor. 13_serial.log:time.c: Detected 1995.061 MHz processor. 14_serial.log:time.c: Detected 1994.917 MHz processor. 15_serial.log:time.c: Detected 4100.735 MHz processor. 16_serial.log:time.c: Detected 2075.800 MHz processor. 17_serial.log:time.c: Detected 2674.350 MHz processor. 18_serial.log:time.c: Detected 1995.002 MHz processor. 19_serial.log:time.c: Detected 1994.978 MHz processor. 1_serial.log:time.c: Detected 4384.310 MHz processor. 20_serial.log:time.c: Detected 1994.969 MHz processor. 21_serial.log:time.c: Detected 3670.696 MHz processor. 22_serial.log:time.c: Detected 1994.997 MHz processor. 23_serial.log:time.c: Detected 2218.613 MHz processor. 24_serial.log:time.c: Detected 1995.048 MHz processor. 25_serial.log:time.c: Detected 1995.015 MHz processor. 26_serial.log:time.c: Detected 1994.957 MHz processor. 27_serial.log:time.c: Detected 1995.051 MHz processor. 28_serial.log:time.c: Detected 1995.021 MHz processor. 29_serial.log:time.c: Detected 3679.640 MHz processor. 2_serial.log:time.c: Detected 2191.105 MHz processor. 30_serial.log:time.c: Detected 1995.086 MHz processor. 31_serial.log:time.c: Detected 1995.071 MHz processor. 32_serial.log:time.c: Detected 1995.051 MHz processor. 33_serial.log:time.c: Detected 2331.760 MHz processor. 34_serial.log:time.c: Detected 1995.011 MHz processor. 35_serial.log:time.c: Detected 1995.050 MHz processor. 36_serial.log:time.c: Detected 1994.911 MHz processor. 37_serial.log:time.c: Detected 1994.905 MHz processor. 38_serial.log:time.c: Detected 1994.881 MHz processor. 39_serial.log:time.c: Detected 1995.027 MHz processor. 3_serial.log:time.c: Detected 2051.467 MHz processor. 40_serial.log:time.c: Detected 1994.987 MHz processor. 41_serial.log:time.c: Detected 1994.970 MHz processor. 42_serial.log:time.c: Detected 1994.952 MHz processor. 43_serial.log:time.c: Detected 1995.042 MHz processor. 44_serial.log:time.c: Detected 1994.998 MHz processor. 45_serial.log:time.c: Detected 1995.016 MHz processor. 46_serial.log:time.c: Detected 1995.006 MHz processor. 47_serial.log:time.c: Detected 1995.000 MHz processor. 4_serial.log:time.c: Detected 1995.112 MHz processor. 5_serial.log:time.c: Detected 1995.081 MHz processor. 6_serial.log:time.c: Detected 2017.303 MHz processor. 7_serial.log:time.c: Detected 1995.046 MHz processor. 8_serial.log:time.c: Detected 1994.951 MHz processor. 9_serial.log:time.c: Detected 2184.754 MHz processor. Regards, Anthony Liguori > So can you try setting KVM_MAX_PIT_INTR_INTERVAL to a lower value? HZ/10 > or something. > > You can confirm this theory by booting the guests with "apic=debug". > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > kvm-devel mailing list > kvm-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/kvm-devel > ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
