Re: 2.5.2-pre1 dbench 32 hangs in vmstat "b" state

Jens Axboe
2001-12-21T22:20:53Z

On Fri, Dec 21 2001, rwhron@earthlink.net wrote:
> On Fri, Dec 21, 2001 at 06:01:56PM +0100, Jens Axboe wrote:
> > Thanks -- could you also try and do sysrq-t back traces when it seems
> > stuck?
> >
> > Does a non-highmem kernel run ok?
> >
> > --
> > Jens Axboe
>
> I recompiled with highmem turned off.
> # CONFIG_HIGHMEM4G is not set
> # CONFIG_HIGHMEM64G is not set
>
> I run a scripty that executes dbench 32, then dbench 128.

Ok, please try something for me. In drivers/block/elevator.c, comment
out this block:

if (q->last_merge) {
__rq = list_entry_rq(q->last_merge);
BUG_ON(__rq->flags & REQ_STARTED);

if ((ret = elv_try_merge(__rq, bio))) {
*req = __rq;
return ret;
}
}

(just #if 0 the entire thing) -- the one inside elevator_linus_merge()

Loop back highmem issue is different, I'll take a look at that later.
I'll be pretty unresponsive over christmas, though.

--
Jens Axboe