Hi everyone, I''m trying to understand the values in /proc/interrupts of unprivileged domains. Specifically, I''m interested in the value of the timer interrupt. AFAIK, this value reflects the number of times this domain received the timer interrupt from Xen? Equivalently, the number of times the timer_interrupt() function (and thus the do_timer_interrupt) function of the guest OS (linux, in this case) were called? Please correct me if I''m wrong. If that is indeed the case, then my real curiosity is this -- what parameters affect this number? Again, AFAIK Xen gives a timer interrupt periodically to a currently running domain, and also when a domain gets scheduled. But how does this indirectly depend on other parameters -- like the cpu frequency, the system time, the tsc timestamp value and so on. TIA Diwaker PS: I''m afraid I might not have been very articular in this email, but I''m happy to give clarifications :) -- Diwaker Gupta http://resolute.ucsd.edu/diwaker ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
Keir Fraser
2004-Dec-15 23:21 UTC
Re: [Xen-devel] /proc/interrupts on unprivileged domains
> Hi everyone, > > I''m trying to understand the values in /proc/interrupts of > unprivileged domains. Specifically, I''m interested in the value of the > timer interrupt. AFAIK, this value reflects the number of times this > domain received the timer interrupt from Xen? Equivalently, the number > of times the timer_interrupt() function (and thus the > do_timer_interrupt) function of the guest OS (linux, in this case) > were called? Please correct me if I''m wrong.All correct.> If that is indeed the case, then my real curiosity is this -- what > parameters affect this number? Again, AFAIK Xen gives a timer > interrupt periodically to a currently running domain, and also when a > domain gets scheduled.Xen gives a domain an interrupt every 10ms while it runs, and every time the domain is rescheduled. It also gives an interrupt whenever the domain''s prgrammable one-shot timer expires (used by Linux to set an appropriate timeout whenever it blocks).> But how does this indirectly depend on other > parameters -- like the cpu frequency, the system time, the tsc > timestamp value and so on.It doesn''t. :-) -- Keir ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel