Messages in this thread | | | Date | Thu, 25 Apr 1996 01:34:18 +0100 | From | "Stephen C. Tweedie" <> | Subject | Re: Read-ahead in kernel |
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Hi,
On Tue, 23 Apr 1996 18:36:24 +0100 (BST), "J.J. Burgess" <92jjb@eng.cam.ac.uk> said:
> The current kernels have almost no idea about read ahead.
Not true.
> To implement read_ahead properly, we need code either in the buffer > cache or ll_rw_blk to a) recognise patterns & b) get this read_ahead > data & put it somewhere.
Nope, the buffer cache is currently used only for things like directories and other metadata (and directory reading does its own readahead anyway, in the fs/ext2fs/ functions). It's the *page cache* which handles most file data IO, and it supports readahead just fine, thank you. There's been quite a lot of work done on it in recent kernels.
Please read linux/mm/filemap.c.
Cheers, Stephen. -- Stephen Tweedie <sct@dcs.ed.ac.uk> Department of Computer Science, Edinburgh University, Scotland.
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