Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 27 Mar 2009 18:28:42 +0200 | From | Tilman Schmidt <> | Subject | Help: tasklet blocked for >8msec |
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A user of the Gigaset base driver (drivers/isdn/gigaset/bas-gigaset.c) reports his connection being dropped exactly every 30 seconds. Analysis of his dmesg indicates that when the error occurs, both the tasklets read_iso_tasklet and write_iso_tasklet handling the B channel data stream (125 USB isochronous packets per second in each direction) are at the same time not executed for an entire inter-packet interval, ie. 8 msecs.
The machine in question, an Intel Core2 Duo E8600 with 4 GB RAM and SATA hard disks, should really be fast enough. CPU load is negligible. I have asked the user to recompile the kernel with CONFIG_PREEMPT=y and to replace the calls to schedule_tasklet() for the two tasklets by schedule_hi_tasklet(). That had no noticeable effect on the problem.
I would be grateful for any hint on what could be the cause for that blockage and how to prevent it.
aTdHvAaNnKcSe Tilman
-- Tilman Schmidt E-Mail: tilman@imap.cc Bonn, Germany Diese Nachricht besteht zu 100% aus wiederverwerteten Bits. Ungeöffnet mindestens haltbar bis: (siehe Rückseite)
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