Greg Smith wrote:
The drives themselves, and possibly the OS and disk controller, are all
running read-ahead algorithms to accelerate this case. In fact, this
*exact* case for the Linux read-ahead stuff that just went mainline
recently: http://kerneltrap.org/node/6642
Apparently only the "simple" stuff hit mainline, see [1] and [2], not
knowing how this turns out for pg-style loads, especially compared to
the full-fledged patch.
Readahead is probably too much of a beast that no one dares to touch
with a 3-foot-pole, unless given a large team with good standing in the
kernel community and concerted regression testing in whatever
environment Linux is used these days...
michael
[1] http://lwn.net/Articles/235164/
[2]
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=history;f=mm/readahead.c
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