Messages in this thread | | | Date | Thu, 1 Apr 2004 17:04:03 -0800 | From | Andrew Morton <> | Subject | Re: Properly stop kernel threads on aic7xxx |
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Andrea Arcangeli <andrea@suse.de> wrote: > > I'm also unsure why _all_ multipage allocations really need this > compound thing setup and why can't the owner of the page take care of > the refcounting itself by always using the head page. I may actually > add a GFP bitflag asking for a multipage but w/o a compound setup. There > are million ways to fix this, none of which is obvious.
For direct-io into higher-order pages. When doing direct-io into a hugetlb page we need to make sure that get_user_pages() pins the correct pageframe.
Possibly we need to turn it on regardless of CONFIG_HUGETLBPAGE for people who want to do direct-io or PEEKTEXT/POKETEXT into mmapped soundcard buffers, for example. Perhaps there's a race which could permit direct-io to write to a freed page via this route..
Davem had some reason why he might want to turn on the compound logic permanently - related to TCP access to/from higher-order pages, I think. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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