[lkml]   [1999]   [Mar]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: disk head scheduling
    On Wed, 24 Mar 1999, Gerard Roudier wrote:

    > You only thought IDE and it what I pointed out, btw.
    > For SCSI with 1 queue per device, if we are globally plugged we lose
    > time (think of SMP, and interruptions), and if we discard the plug, we
    > may break the coalescencing and sorting, and then just provide devices
    > with bunches small IOs.

    I admit that not implementing per-queue plugs at that time was a mistake.
    The time in which the plug is being held should be very short relative to
    actual I/O times, though, just enough to let the higher layers complete
    putting all those small requests and colaescencing them, which is a
    CPU <--> memory operation.



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

     \ /
      Last update: 2005-03-22 13:51    [W:0.018 / U:0.776 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site