Hello, I am using Xen 3.3.1-rc1-pre with SEDF scheduler. From time to time the SEDF scheduler behaves in a strange fashion: The scheduling timer s_timer expires much to early. This causes the scheduler to run very often and in very short distances. The xentrace output appended to this mail shows this situation. I have added own xentrace events ( sched-enter, do_sedf_schedule, sched_left, sedf_wake) to the source code. In line 17 of the xentrace output, the SEDF scheduler chooses the idle-task to run next for maximal 45864ns (ret.time). In schedule() the scheduling timer s_timer is then set to now+ret.time according to the source code. But the scheduling timer s_timer expires already after 2230ns and not as expected after 45.864ns (line 19). This goes on for many times. This behaviour also appears, when dom0 or any other domU are scheduled. Can anybody please tell me the reason for this behaviour? For me, this behaviour is bad, because it increases latency while sending network pakets. Thanks in advance, Thomas _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel