Re: Overload question
Re: Overload question
- Subject: Re: Overload question
- From: Jeff Moore <email@hidden>
- Date: Tue, 11 Oct 2005 11:13:31 -0700
It would help if I could see all of the telemetry, especially the
cycles before and after. A screen shot would be fine. It would also
help to know what the IO cycle duration in samples is.
At any rate, the start time for the IO cycle is not necessarily the
same value as the host time displayed for the cycle event. They are
taken from different fields in the event data sometimes.
Feel free to talk to me off-list if you have large attachments to send.
On Oct 10, 2005, at 6:24 PM, Ted Barram wrote:
Hi,
I’m looking for the cause of some sporadic overload notifications
with one of our usb devices. When I analyze the overload in the IO
Cycle Telemetry window, I see that there is a large diff between
the main ‘Start’ timestamp (next to the UI arrow) and the ‘->Cycle”
timestamp (about 1ms). This diff appears to be the cause of the
overload, because all the other timestamp diffs look reasonable
(and are the same as in other non-overload cycles.)
Here’s a snippet of the first few entries on the first 2 lines (the
V represents the UI arrow):
V 93327.517 ( +2.663 +0.030)
->Cycle: 34993 93328.604 ( +0.000)
The diff between 93328.604 and 93327.517 is what appears top be
causing the overload. In all other non-overload cycles this diff is
much smaller, typically .003 ms.
So it looks as if something is pre-empting the IOProc, but it
always happens at the same place, ie right at the very beginning,
so I wonder of something else is going on.
One other difference that I see in the overload cycle compared with
the other cycles is that the Wake:samp time is later, it’s 181
samples on the overload cycle as compared to 128 samples on the
succesful cycles.
Thanks in advance, if any more data is needed let me know.
-Ted
--
Jeff Moore
Core Audio
Apple
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden