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    SubjectRe: Short question regarding generic_make_request()
    Jens Axboe wrote:
    >
    > On Sun, Feb 03 2002, Ingo Molnar wrote:
    > >
    > > On Sun, 3 Feb 2002, Steffen Persvold wrote:
    > >
    > > > Can generic_make_request() be called from interrupt level (or tasklet)
    > > > ?
    > >
    > > no.
    >
    > In theory, READA from interrupt context would be ok, though. That
    > doesn't work in real-life due to the non flag saving spin locking in
    > __make_request.
    >

    Ok, the reason I'm asking is that I receive a request from a remote machine on interrupt level
    (tasklet) and want to submit this to the local device. The reason I'm using a tasklet instead of a
    kernel thread is that somewhere between RedHat's 2.4.3-12 and 2.4.9-12 kernels the latency of waking
    up a kernel thread increased (using a semaphore method similar to the one used in loop.c). I don't
    know why this happened, but I guess that if I still could use a kernel thread there wouldn't be any
    problems using generic_make_request().

    Regards,
    --
    Steffen Persvold | Scalable Linux Systems | Try out the world's best
    mailto:sp@scali.com | http://www.scali.com | performing MPI implementation:
    Tel: (+47) 2262 8950 | Olaf Helsets vei 6 | - ScaMPI 1.13.8 -
    Fax: (+47) 2262 8951 | N0621 Oslo, NORWAY | >320MBytes/s and <4uS latency
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