lkml.org 
[lkml]   [2005]   [Apr]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Regarding posted scsi midlyaer patchsets
    On Mon, Apr 18 2005, Tejun Heo wrote:
    > And, James, regarding REQ_SOFTBARRIER, if the REQ_SOFTBARRIER thing can
    > be removed from SCSI midlayer, do you agree to change REQ_SPECIAL to
    > mean special requests? If so, I have three proposals.
    >
    > * move REQ_SOFTBARRIER setting to right after the allocation of
    > scsi_cmnd in scsi_prep_fn(). This will be the only place where
    > REQ_SOFTBARRIER is used in SCSI midlayer, making it less pervasive.
    > * Or, make another API which sets REQ_SOFTBARRIER on requeue. maybe
    > blk_requeue_ordered_request()?
    > * Or, make blk_insert_request() not set REQ_SPECIAL on requeue. IMHO,
    > this is a bit too subtle.
    >
    > I like #1 or #2. Jens, what do you think? Do you agree to remove
    > requeue feature from blk_insert_request()?

    #2 is the best, imho. We really want to maintain ordering on requeue
    always, marking it softbarrier automatically in the block layer means
    the io schedulers don't have to do anything specific to handle it.

    I have no problem with removing the requeue stuff from
    blk_insert_request(). That function is horribly weird as it is, it is
    supposed to look generic but is really just a scsi special case.

    --
    Jens Axboe

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-04-19 14:38    [W:4.173 / U:0.484 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site