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    SubjectRe: [UPDATE PATCH] ieee1394/sbp2: use ssleep() instead of schedule_timeout()
    On Sun, Jan 09, 2005 at 10:01:21AM +0100, Stefan Richter wrote:
    > Nishanth Aravamudan wrote:
    > >Description: Use ssleep() instead of schedule_timeout() to guarantee
    > >the task
    > >delays as expected. The existing code should not really need to run in
    > >TASK_INTERRUPTIBLE, as there is no check for signals (or even an
    > >early return
    > >value whatsoever). ssleep() takes care of these issues.
    > >--- 2.6.10-v/drivers/ieee1394/sbp2.c 2004-12-24 13:34:00.000000000
    > >-0800
    > >+++ 2.6.10/drivers/ieee1394/sbp2.c 2005-01-05 14:23:05.000000000 -0800
    > >@@ -902,8 +902,7 @@ alloc_fail:
    > > * connected to the sbp2 device being removed. That host would
    > > * have a certain amount of time to relogin before the sbp2 device
    > > * allows someone else to login instead. One second makes sense. */
    > >- set_current_state(TASK_INTERRUPTIBLE);
    > >- schedule_timeout(HZ);
    > >+ ssleep(1);
    > Maybe the current code is _deliberately_ accepting interruption by
    > signals but trying to complete sbp2_probe() anyway. However it seems
    > more plausible to me to abort the device probe, for example like this:
    > if (msleep_interruptible(1000)) {
    > sbp2_remove_device(scsi_id);
    > return -EINTR;
    > }

    You might be right, but I'd like to get Ben's input on this, as I honeslty am
    unsure. To be fair, I am trying to audit all usage of schedule_timeout() and the
    semantic interpretation (to me) of using TASK_INTERRUPTIBLE is that you wish to
    sleep a certain amount of time, but also are prepared for an early return on
    either signals or wait-queue events. msleep_interruptible() cleanly removes this
    second issue, but still requires the caller to respond appropriately if there is
    a return value. Hence, I like your change. I think it makes the most sense.
    Since I didn't/don't know how the device works, I was not able to make the
    change myself. Thanks for your input!

    > Anyway, signal handling does not appear to be critical there.

    Just out of curiousity, doesn't that run the risk, though, of
    signal_pending(current) being true for quite a bit of time following the

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