Messages in this thread | | | Date | Thu, 17 Nov 2005 15:29:00 -0800 (PST) | Subject | Re: [PATCH 01/11] unpaged: get_user_pages VM_RESERVED | From | "David S. Miller" <> |
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From: Hugh Dickins <hugh@veritas.com> Date: Thu, 17 Nov 2005 19:29:17 +0000 (GMT)
> The PageReserved removal in 2.6.15-rc1 prohibited get_user_pages on the > areas flagged VM_RESERVED in place of PageReserved. That is correct in > theory - we ought not to interfere with struct pages in such a reserved > area; but in practice it broke BTTV for one. > > So revert to prohibiting only on VM_IO: if someone gets into trouble > with get_user_pages on VM_RESERVED, it'll just be a "don't do that". > > You can argue that videobuf_mmap_mapper shouldn't set VM_RESERVED in the > first place, but now's not the time for breaking drivers without notice. > > Signed-off-by: Hugh Dickins <hugh@veritas.com>
It might be a nice little 2.6.16 project to simplify that videobuf_mmap_mapper() code, and in fact other driver subsystems want a similar facility, such as DVB.
So putting some helper routines in the core MM for this, in one spot, seems like the long term way to handle this peculiar stuff. - 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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