Avi Kivity wrote: > Jan Kiszka wrote: >> Avi Kivity wrote: >> >>> Jan Kiszka wrote: >>> >>>> I ran >>>> >>>> user/kvmctl user/test/bootstrap user/test/smp.flat >>>> >>>> with the busy loop hacked into bootstrap, but I got no latency spots >>>> this time. And what should I look for in the output of kvm_stat? >>>> >>>> >>>> >>> The first numeric column is the total number of exits; the second is the >>> rate of change (per second). For a spinning workload, both irq_exits >>> and exits rate should equal the timer frequency. >>> >> It matches roughly, but this isn't surprising given the lack of latency >> peaks in this scenario. >> >> > > Okay, that's expected. But I really can't think what causes the latency > spike you see running the bios code. 300 microseconds is enough for 3000 > cache misses. No instruction can cause so many except rep movs and > friends, and these are supposed to be preemptible. > > You might try isolating it by adding code to output markers to some I/O > port and scattering it throughout the bios. A binary search should find > the problem spot quickly. >
Got it! It's wbinvd from smm_init in rombios32.c! Anyone any comments on this? Jan (who's leaving now...) -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
