Messages in this thread | | | Subject | Re: Comment on patch to remove nr_async_pages limit | From | Zlatko Calusic <> | Date | 05 Jun 2001 17:57:45 +0200 |
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Mike Galbraith <mikeg@wen-online.de> writes:
> On Mon, 4 Jun 2001, Marcelo Tosatti wrote: > > > Zlatko, > > > > I've read your patch to remove nr_async_pages limit while reading an > > archive on the web. (I have to figure out why lkml is not being delivered > > correctly to me...) > > > > Quoting your message: > > > > "That artificial limit hurts both swap out and swap in path as it > > introduces synchronization points (and/or weakens swapin readahead), > > which I think are not necessary." > > > > If we are under low memory, we cannot simply writeout a whole bunch of > > swap data. Remember the writeout operations will potentially allocate > > buffer_head's for the swapcache pages before doing real IO, which takes > > _more memory_: OOM deadlock. > > What's the point of creating swapcache pages, and then avoiding doing > the IO until it becomes _dangerous_ to do so? That's what we're doing > right now. This is a problem because we guarantee it will become one. > We guarantee that the pagecache will become almost pure swapcache by > delaying the writeout so long that everything else is consumed. >
Huh, this looks just like my argument, just put in different words. I should have read this sooner. :) -- Zlatko - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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