Re: pre8: where has the anti-hog code gone?

[arjan@fenrus.demon.nl (Arjan van de Ven)]

[snip stuff about "first make it work, then make it nice/fast"]

> So pre-8 with your suggested for for kswapd() looks pretty good, actually,
> but still has this issue that try_to_free_pages() seems to give up too
> easily and return failure when it shouldn't. 

I have been looking at it right now, and I think there are a few issues:

1) shrink_[id]node_memory always return 0, even if they free memory
2) shrink_inode_memory is broken for priority == 0

2) is easily fixable, but even with that fixed, my traces show that, for the
mmap002 test, shrink_mmap fails just before the OOM.

My idea is (but I have not tested this) that for priority == 0 (aka "Uh oh")
shrink_mmap or do_try_to_free_pages have to block while waiting for pages to
be commited to disk. As far as I can see, shrink_mmap just skips pages that
are being commited to disk, while these could be freed when they are waited
upon. 

Greetings,
    Arjan van de Ven
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