Messages in this thread |  | | Date | Tue, 6 Feb 2001 21:07:04 +0100 | From | Jens Axboe <> | Subject | Re: [Kiobuf-io-devel] RFC: Kernel mechanism: Compound event wait |
| |
On Tue, Feb 06 2001, Ingo Molnar wrote: > > This small correction is the crux of the problem: if it blocks, it > > takes away from the ability of the process to continue doing useful > > work. If it returns -EAGAIN, then that's okay, the io will be > > resubmitted later when other disk io has completed. But, it should be > > possible to continue servicing network requests or user io while disk > > io is underway. > > typical blocking point is waiting for page completion, not > __wait_request(). But, this is really not an issue, NR_REQUESTS can be > increased anytime. If NR_REQUESTS is large enough then think of it as the > 'absolute upper limit of doing IO', and think of the blocking as 'the > kernel pulling the brakes'.
Not just __get_request_wait, but also the limit on max locked buffers in ll_rw_block. Serves the same purpose though, brake effect.
-- Jens Axboe
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
|  |