Messages in this thread | | | Date | Thu, 14 Sep 2000 16:12:01 +0200 | From | "Andi Kleen" <> | Subject | Re: elevator code |
| |
On Thu, Sep 14, 2000 at 04:00:31PM +0200, Andrea Arcangeli wrote: > On Wed, 13 Sep 2000, Andi Kleen wrote: > > >I guess it boils down to that the plugging (run_task(&tq_disc)) is overloaded > >in Linux. It does merging of requests which are the same anyways (=from the > >same operation in upper layers) and merging of requests that are unrelated. > > &tq_disk doesn't merge anything. It only tells the driver to start eating > the requests in the queue. The driver will just blindy process them and if > they're big with many bh on them it will do scatter gather with lots of > I/O in one scsi command. If they're small, the driver will produce 4k/1k > sized scsi commands as worse (same for IDE).
Sorry, i've been imprecise in my wording. I really meant "controls the end of merging" with "does the merging"
-Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
| |