On Thu, Nov 6, 2014 at 6:01 AM, Michal Nazarewicz <min...@mina86.com> wrote: >> On Tue, Nov 04 2014, Gregory Fong wrote: >>> The alignment in cma_alloc() is done w.r.t. the bitmap. This is a >>> problem when, for example: >>> >>> - a device requires 16M (order 12) alignment >>> - the CMA region is not 16 M aligned > > On Wed, Nov 05 2014, Weijie Yang wrote: >> I think the device driver should ensure that situation could not occur, >> by assign suitable alignment parameter in cma_declare_contiguous(). > > What about default CMA area? Besides, I think principle of least > surprise applies here and alignment should be physical.
I agree the current code doesn't handle this issue properly. However, I prefer to add specific usage to CMA interface rather than modify the cma code, Because the latter hide the issue and could waste memory. > -- > Best regards, _ _ > .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o > ..o | Computer Science, Michał “mina86” Nazarewicz (o o) > ooo +--<m...@google.com>--<xmpp:min...@jabber.org>--ooO--(_)--Ooo-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
