Messages in this thread | | | Date | Tue, 28 Mar 2000 02:25:48 +0200 (CEST) | From | Andrea Arcangeli <> | Subject | Re: kernel performance & profiles under heavy disk I/O |
| |
On 20 Mar 2000, Dimitris Michailidis wrote:
>faster than 2.3.99-pre2. Notice the increase in the number of IRQs from the >disk controller (~250%) and the increase in scheduling activity (~400%), a >good deal of which is due to __get_request_wait.
Since 2.3.99-pre1 you can tune the elevator with an userspace tools avaiable in the latest util-linux (see Changes for the URL). With elvtune you can tune the elevator at runtime to give you a behaviour close to the one of 2.3.40 if you really want to do so.
The current values gives good performance and good inteactiveness, if you don't care about interactiveness you are free to change that.
laser:~ # elvtune /dev/hda
/dev/hda elevator ID 0xc02370e4 read_latency: 128 write_latency: 8192 max_bomb_segments: 4
laser:~ # elvtune -r 100000 -w 100000 -b 128 /dev/hda
/dev/hda elevator ID 0xc02370e4 read_latency: 100000 write_latency: 100000 max_bomb_segments: 128
Something like the above should give you bad interactiveness (not infinite as 2.2.x at least) but more aggressive ordering and coalescing of the requests.
There's also a manpage that explains some of the details of the parameter.
Thank you for the feedback.
Andrea
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |