Messages in this thread | | | Subject | Re: Possible Idea with filesystem buffering. | From | (Eric W. Biederman) | Date | 21 Jan 2002 08:37:12 -0700 |
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Hans Reiser <reiser@namesys.com> writes:
> Mark Hahn wrote: > > >On Sun, 20 Jan 2002, Hans Reiser wrote: > > > >> Write clustering is one thing it achieves. When we flush a slum, the > > > >sure, that's fine. when the VM tells you to write a page, > >you're free to write *more*, but you certainly must give back > > that particular page. afaicr, this was the conclusion of the long-ago thread > > that you're referring to. > > > >regards, mark hahn. > > > > > > > This is bad for use with internal nodes. It simplifies version 4 a bunch to > assume that if a node is in cache, its parent is also. Not sure what to do > about it, maybe we need to copy the node. Surely we don't want to copy it > unless it is a DMA related page cleaning.
Increment the count on the parent page, and don't decrement it until the child goes away. This might need a notification from page_cache_release when so you can decrement the count at the appropriate time. But internal nodes are ``meta'' data which has always had special freeing rules.
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