From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xose Vazquez Perez Date: Fri, 30 Apr 2010 20:33:21 +0000 Subject: Re: [PATCH 1/1] dasd: do not force use of deadline IO scheduler Message-Id: <4BDB3E91.8070505@gmail.com> To: linux-s390@vger.kernel.org List-ID: On 2008-03-04 8:52:10, Martin Schwidefsky wrote: a bit old. > On Mon, 2008-03-03 at 15:21 -0500, Josef 'Jeff' Sipek wrote: >> Signed-off-by: Josef 'Jeff' Sipek >> --- >> drivers/s390/block/dasd.c | 9 --------- >> 1 files changed, 0 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c >> index ccf46c9..4d4f6ff 100644 >> --- a/drivers/s390/block/dasd.c >> +++ b/drivers/s390/block/dasd.c >> @@ -1946,21 +1946,12 @@ static void do_dasd_request(struct request_queue *queue) >> */ >> static int dasd_alloc_queue(struct dasd_block *block) >> { >> - int rc; >> - >> block->request_queue = blk_init_queue(do_dasd_request, >> &block->request_queue_lock); >> if (block->request_queue == NULL) >> return -ENOMEM; >> >> block->request_queue->queuedata = block; >> - >> - elevator_exit(block->request_queue->elevator); >> - rc = elevator_init(block->request_queue, "deadline"); >> - if (rc) { >> - blk_cleanup_queue(block->request_queue); >> - return rc; >> - } >> return 0; >> } > > Um, why? We have a reason to force the deadline scheduler, our > performance test have shown that the deadline scheduler get the highest > throughout out of the storage subsystems which are used with the > machines. Are there recent tests, cfq vs. deadline, with current kernels? This FCP/SCSI test is a bit old(2005-03-16), and cfq vs. deadline shows no differences: http://www.ibm.com/developerworks/linux/linux390/perf/tuning_res_dasd_ioScheduler.html Any DASD test out there ? -thanks- -- �All� muevan feroz guerra, ciegos reyes por un palmo m�s de tierra; que yo aqu� tengo por m�o cuanto abarca el mar brav�o, a quien nadie impuso leyes. Y no hay playa, sea cualquiera, ni bandera de esplendor, que no sienta mi derecho y d� pecho a mi valor.�