Messages in this thread | | | Date | Wed, 16 Jan 2002 09:42:23 +0200 (IST) | From | Amar Lior <> | Subject | sys_readahead. |
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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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