Messages in this thread | | | Date | Thu, 25 Oct 2001 19:33:43 +0200 | From | Jens Axboe <> | Subject | Re: xmm2 - monitor Linux MM active/inactive lists graphically |
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On Thu, Oct 25 2001, Linus Torvalds wrote: > > On 25 Oct 2001, Zlatko Calusic wrote: > > > > Yes, I definitely have DMA turned ON. All parameters are OK. :) > > I suspect it may just be that "queue_nr_requests"/"batch_count" is > different in -ac: what happens if you tweak them to the same values? > > (See drivers/block/ll_rw_block.c) > > I think -ac made the queues a bit deeper the regular kernel does 128 > requests and a batch-count of 16, I _think_ -ac does something like "2 > requests per megabyte" and batch_count=32, so if you have 512MB you should > try with > > queue_nr_requests = 1024 > batch_count = 32
Right, -ac keeps the elevator flow control and proper queue sizes.
-- Jens Axboe
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