site_archiver@lists.apple.com Delivered-To: Darwin-dev@lists.apple.com while (1) { Is this a known issue in 10.3.xxx version of the system? Thanks Stephane Letz _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... We are debugging a strange issue with abnormal CPU spikes occurring in a test application. The test starts a time-constraint thread running with period = 1000 us, computation = 500 us, constraint = 1000 us. In the test, the thread does nothing but reschedule itself every 1000 us, basically doing: next_absolute_name = current_absolute_date (using "mach_absolute_time" based code) + 1000 us (converted in absolute date) ; mach_wait_until(next_absolute_name); } (the real code maintains an absolute value incremented exactly by 1000 us to avoid timing deviation...) On 10.3.9 the average CPU use on a dual G5 is 0%... but we get CPU spike up to 50-60 % on a dual G5 (up to 90% on the mono G5) every 3-4 minutes in the RT thread. On 10.4.3, the average CPU use on a dual G5 is now 0.6 %, but there is no more CPU spike .... This email sent to site_archiver@lists.apple.com