Date: Sat, 19 Feb 2011 01:10:07 +1030 From: "Daniel O'Connor" <doconnor@gsoft.com.au> To: "Daniel O'Connor" <doconnor@gsoft.com.au> Cc: freebsd-usb@freebsd.org Subject: Re: libusb performance on 8.1 Message-ID: <FF467587-6B4C-4F46-9B8B-C5041E4B224E@gsoft.com.au> In-Reply-To: <0F80A010-B97C-4D05-B604-5EF4B07EF248@gsoft.com.au> References: <9CF6C32F-E230-446B-94FC-C57F0F02B0E4@gsoft.com.au> <201101221433.23194.hselasky@c2i.net> <6AD22899-0B00-483D-A01E-786029A82C9F@gsoft.com.au> <201101280858.05077.hselasky@c2i.net> <0F80A010-B97C-4D05-B604-5EF4B07EF248@gsoft.com.au>
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On 03/02/2011, at 17:26, Daniel O'Connor wrote: > BTW do you have a feel for the latency in bulk vs iso? I currently = have 5-10 msec of buffering in the hardware which I plan on increasing = but I'm not sure what a reasonable amount would be :) I increased this by a factor of 8 but I still get drop outs during disk = activity. I timed libusb_handle_events_timeout() with a timeout of 1 millisecond = and it quite often exceeds this (by a significant amount) eg.. Triggered at 1298039742 2011/02/18 14:35:27:ugsio_child: libusb took > 10msec - 32.44 ms 2011/02/18 14:35:27:ugsio_child: libusb took > 10msec - 27.19 ms 2011/02/18 14:35:27:ugsio_child: libusb took > 10msec - 25.27 ms 2011/02/18 14:35:27:ugsio_child: libusb took > 10msec - 21.83 ms 2011/02/18 14:35:36:ugsio_child: libusb took > 10msec - 48.23 ms Error during acquisition - ERROR:305 UGSIO aborted transfer: stalled (still using bulk transfers for now) -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
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