lkml.org 
[lkml]   [2004]   [May]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Cache queue_congestion_on/off_threshold
    On Tue, May 11 2004, Chen, Kenneth W wrote:
    > >>>> Jens Axboe wrote on Monday, May 10, 2004 7:30 AM
    > > > >
    > > > > Actually, with the good working batching we might get away with killing
    > > > > freereq completely. Have you tested that (if not, could you?)
    > > >
    > > > Sorry, I'm clueless on "good working batching". If you could please give
    > > > me some pointers, I will definitely test it.
    > >
    > > Something like this.
    > >
    > > --- linux-2.6.6/drivers/block/ll_rw_blk.c~ 2004-05-10 16:23:45.684726955 +0200
    > > +++ linux-2.6.6/drivers/block/ll_rw_blk.c 2004-05-10 16:29:04.333792268 +0200
    > > @@ -2138,8 +2138,8 @@
    > >
    > > static int __make_request(request_queue_t *q, struct bio *bio)
    > > {
    > > - struct request *req, *freereq = NULL;
    > > int el_ret, rw, nr_sectors, cur_nr_sectors, barrier, ra;
    > > + struct request *req;
    > > sector_t sector;
    > >
    > >
    > > [snip] ...
    >
    > I'm still working on this. With this patch, several processes stuck
    > in "D" state and never finish. Suspect it's the barrier thing, it
    > jumps through blk_plug_device() and might goof up the queue afterwards.

    BTW, the barrier bit was buggy, but it could not make a difference since
    the stock kernels + -mm doesn't use barriers. So you are right it's
    wrong, but no impact on this test.

    --
    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: 2005-03-22 14:03    [W:0.033 / U:0.008 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site