Messages in this thread | | | Date | Tue, 29 Jan 2002 16:34:55 -0200 (BRST) | From | Rik van Riel <> | Subject | Re: 2.4: NFS client kmapping across I/O |
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On Tue, 29 Jan 2002, Hugh Dickins wrote: > On Mon, 28 Jan 2002, Xeno wrote: > > > > Now I also have time to mention the other NFS client issue we ran into > > recently, I have not found mention of it on the mailing lists. The NFS > > client is kmapping pages for the duration of reads from and writes to > > the server. This creates a scaling limitation, especially under > > You're right that kmap users should avoid holding them for very long, > I'd certainly not discourage anyone from pursuing that effort.
Things like this would be fixed by having a kmap variant which maps the pages into process-private space, kind of like kmap_atomic(), but into a (4 MB sized?) part of address space which is only visible within this process.
This would mean that each process can have a few MB of kmap()d pages ... should be nice for things like having copy_{to,from}_user "cache" the hot pages while keeping longer term mappings from filling the global pool.
regards,
Rik -- DMCA, SSSCA, W3C? Who cares? http://thefreeworld.net/
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