On 07/11/2012 13:22, "Ian Campbell" <[email protected]> wrote:
>>> (XEN) XXX plt_overflow: plt_now=5ece12d34128 plt_wrap=5ece12d09306 >>> now=5ece12d16292 old_stamp=35c7c new_stamp=800366a5 >>> plt_stamp64=15b800366a5 plt_mask=ffffffff tsc=e3839fd23854 >>> tsc_stamp=e3839fcb0273 >> >> (below is the complete xm dmesg output) >> >> did that help you ? do you need more info ? > > I'll leave this to Keir (who wrote the debugging patch) to answer but it > looks to me like it should be useful! I'm scratching my head. plt_wrap is earlier than plt_now, which should be impossible. plt_stamp64 oddly has low 32 bits identical to new_stamp. That seems very very improbable! I wonder whether the overflow handling should just be removed, or made conditional on a command-line parameter, or on the 32-bit platform counter being at least somewhat likely to overflow before a softirq occurs -- it seems lots of systems are using 14MHz HPET, and that gives us a couple of minutes for the plt_overflow softirq to do its work before overflow occurs. I think we would notice that outage in other ways. :) -- Keir -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
