Re: ll_rw_block/submit_bh and request limits

[Marcelo Tosatti]

On Thu, 22 Feb 2001, Andrea Arcangeli wrote:

<snip>

> However if you have houndred of different queues doing I/O at the same
> time it may make a difference, but probably with tons of harddisks
> you'll also have tons of ram... In theory we could put a global limit
> on top of the the per-queue one. Or we could at least upper bound the
> total_ram / 3.

The global limit on top of the per-queue limit sounds good. 

Since you're talking about the "total_ram / 3" hardcoded value... it
should be /proc tunable IMO. (Andi Kleen already suggested this)