Messages in this thread |  | | | Date | Thu, 12 Jun 2003 05:04:12 +0200 | | From | Andrea Arcangeli <> | | Subject | Re: [PATCH] io stalls |
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On Thu, Jun 12, 2003 at 12:51:30PM +1000, Nick Piggin wrote: > I guess you could fix this by having a "last woken" flag, and > allow that process to allocate requests without blocking from > the batch limit until the queue full limit. That is how > batch_requests is supposed to work.
I see what you mean, I did care about the case of each request belonging to a different task, but of course this doesn't work if there's just one task. In such case there will be a single wakeup and one for each request, so it won't be able to eat all the requests and it'll keep hanging on the full bitflag. So yes, the ->full bit partly disabled the batch sectors in presence of only 1 task. With multiple tasks and the wake_up_nr batch_sectors will still work. However I don't care about that right now ;), it's a minor issue I guess, single task I/O normally doesn't seek heavily so more likely it will run into the oversized queue before being able to take advantage of the batch sectors.
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