Messages in this thread | | | Date | Thu, 10 Oct 2002 15:50:50 -0700 | From | Mike Fedyk <> | Subject | Re: [PATCH] O_STREAMING - flag for optimal streaming I/O |
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On Thu, Oct 10, 2002 at 03:39:19PM +0200, Giuliano Pochini wrote: > > > Look, the pagecache is already smart. New stuff will replace unusued > > old stuff. On VM pressure, the pagecache will be pruned. Streaming I/O > > is a fundamentally different problem in that the data is so large it > > _continually_ thrashes the pagecache. Such I/O is sequential and > > use-once. You end up with a permanent waste of memory (the cached > > I/O). > > When a process opens a file with O_STREAMING, it tells the kernel > it will use the data only once, but it tells nothing about other > tasks. If that process reads something which is already cached, > then it must not drop it because someone other used it recently > and IMHO pagecache only should be allowed to drop it. >
You are missing the point. If the app thinks that might happen, it shouldn't use O_STREAMING.
Though, how do you get around some binary app using O_STREAMING when it shouldn't? - 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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