Messages in this thread Patch in this message | | | Date | Wed, 22 Oct 2003 19:54:46 +1000 | From | Nick Piggin <> | Subject | Re: [BENCHMARK] I/O regression after 2.6.0-test5 |
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rwhron@earthlink.net wrote:
>>If you have time, would you please try testing as-iosched.c from >>test5 in a later kernel (it won't go into test8-mm1 though). >> > >copying drivers/block/as-iosched.c from 2.6.0-test5 to test8 >looks like it fixes the regression. Here are the results so far. >
Could you please try the following patch against 2.6.0-test8. Thanks. I'll have to come up with something more comprehensive because this destroys find | xargs grep during other IO. It looks like this might be the cause of a lot of AS's database problems though.
I'm working on something...
linux-2.6-npiggin/drivers/block/as-iosched.c | 23 +++-------------------- 1 files changed, 3 insertions(+), 20 deletions(-)
diff -puN drivers/block/as-iosched.c~as-fix drivers/block/as-iosched.c --- linux-2.6/drivers/block/as-iosched.c~as-fix 2003-10-22 19:47:48.000000000 +1000 +++ linux-2.6-npiggin/drivers/block/as-iosched.c 2003-10-22 19:49:41.000000000 +1000 @@ -99,7 +99,6 @@ struct as_data { sector_t last_sector[2]; /* last REQ_SYNC & REQ_ASYNC sectors */ struct list_head *dispatch; /* driver dispatch queue */ struct list_head *hash; /* request hash */ - unsigned long new_success; /* anticipation success on new proc */ unsigned long current_batch_expires; unsigned long last_check_fifo[2]; int changed_batch; /* 1: waiting for old batch to end */ @@ -585,18 +584,11 @@ static void as_antic_stop(struct as_data int status = ad->antic_status; if (status == ANTIC_WAIT_REQ || status == ANTIC_WAIT_NEXT) { - struct as_io_context *aic; - if (status == ANTIC_WAIT_NEXT) del_timer(&ad->antic_timer); ad->antic_status = ANTIC_FINISHED; /* see as_work_handler */ kblockd_schedule_work(&ad->antic_work); - - aic = ad->io_context->aic; - if (aic->seek_samples == 0) - /* new process */ - ad->new_success = (ad->new_success * 3) / 4 + 256; } } @@ -612,14 +604,8 @@ static void as_antic_timeout(unsigned lo spin_lock_irqsave(q->queue_lock, flags); if (ad->antic_status == ANTIC_WAIT_REQ || ad->antic_status == ANTIC_WAIT_NEXT) { - struct as_io_context *aic; ad->antic_status = ANTIC_FINISHED; kblockd_schedule_work(&ad->antic_work); - - aic = ad->io_context->aic; - if (aic->seek_samples == 0) - /* new process */ - ad->new_success = (ad->new_success * 3) / 4; } spin_unlock_irqrestore(q->queue_lock, flags); } @@ -708,11 +694,10 @@ static int as_can_break_anticipation(str return 1; } - if (ad->new_success < 256 && - (aic->seek_samples == 0 || aic->ttime_samples == 0)) { + if (aic->seek_samples == 0 && aic->ttime_samples == 0) { /* - * Process has just started IO and we have a bad history of - * success anticipating on new processes! + * Process has just started IO. Don't anticipate. + * TODO! Must fix this up. */ return 1; } @@ -1822,8 +1807,6 @@ static int as_init(request_queue_t *q, e if (ad->write_batch_count < 2) ad->write_batch_count = 2; - ad->new_success = 512; - return 0; } _
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