[lkml]   [2006]   [Dec]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [RFC PATCH 1/8] rqbased-dm: allow blk_get_request() to be called from interrupt context
    On Fri, Dec 22 2006, Christoph Hellwig wrote:
    > On Wed, Dec 20, 2006 at 12:50:02PM -0500, Kiyoshi Ueda wrote:
    > > Because I'd like to use blk_get_request() in q->request_fn()
    > > which can be called from interrupt context like below:
    > > scsi_io_completion -> scsi_end_request -> scsi_next_command
    > > -> scsi_run_queue -> blk_run_queue -> q->request_fn
    > > Or request should not be allocated in q->request_fn() anyway?
    > > Do you have any other ideas?
    > The right long-term fix is to make sure request_fn is only ever called
    > from process context. This means moving retry handling to a thread instead
    > of a softirq, but this will need careful performance testing and tweaking.

    It's a lot more than just retry handling. Most driver reinvoke queueing
    from the completion handling, so basically most of the time request_fn
    is run from either softirq (like SCSI) or interrupt context (like IDE).

    Jens Axboe

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2006-12-22 18:33    [W:0.020 / U:5.224 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site