James Harper
2005-May-20 01:54 UTC
RE: [Xen-devel] asterisk, ztdummy, and usb (and HZ = 100 under xen ???)
The x86 arch sets the kernel internal timer to 1000HZ by default, but xen seems to set it to 100HZ (2.4 default). The ztdummy driver makes the assumption that under 2.6, HZ = 1000, but this isn''t the case under xen which is probably the cause of all my problems. Is there a problem with me changing this, or is there a dynamic way to change this??? Thanks James> -----Original Message----- > From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel- > bounces@lists.xensource.com] On Behalf Of James Harper > Sent: Friday, 20 May 2005 11:20 > To: James Harper; Xen-devel@lists.xensource.com > Subject: RE: [Xen-devel] asterisk, ztdummy, and usb > > Reading the docs more closely, it looks like the ztdummy module undera> 2.6 kernel uses the rtc to generate interrupts at the required > precision. What sort of rtc interface does xen give the domains? > > Thanks > > James_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2005-May-20 07:56 UTC
Re: [Xen-devel] asterisk, ztdummy, and usb (and HZ = 100 under xen ???)
On 20 May 2005, at 02:54, James Harper wrote:> The x86 arch sets the kernel internal timer to 1000HZ by default, but > xen seems to set it to 100HZ (2.4 default). > > The ztdummy driver makes the assumption that under 2.6, HZ = 1000, but > this isn''t the case under xen which is probably the cause of all my > problems. > > Is there a problem with me changing this, or is there a dynamic way to > change this???Having HZ differ between Xen and a guest doesn''t really matter that much. The guest will get fewer upcalls than it expects, but it will count ten ticks for each upcall. So I doubt that thsi is your problem. Does ztdummy use the rtc driver? I''m not sure how weel we support that on Xen... -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel