Hi all,
I tried to use the new syscall readahead and i found out the
following in do_readahead (mm/filemap.c)
--------------------------------------------------
.....
/* And limit it to a sane percentage of the inactive list..*/
max = nr_inactive_pages/ 2;
if (nr > max)
nr = max;
while (nr) {
page_cache_read(file, index);
index++;
nr--;
}
....
---------------------------
My question is why use only nr_inactive_pages/2. I checked this
value on unloaded machine and it was very very small (~100) pages.
While the nr_free_pages() value was much larger.
Why not take into consideration also the value of nr_free_pages()
and do something like
max = (nr_inactive_pages + nr_free_pages())/ 2;
So if i have free pages i would be able to perform large readaheads
10x
--lior
________________________________________________________________
Lior Amar Distributed Computing Lab MOSIX
E-mail : lior@cs.huji.ac.il
________________________________________________________________
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