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author | Rusty Russell <rusty@rustcorp.com.au> | 2007-11-12 13:39:18 +1100 |
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committer | Rusty Russell <rusty@rustcorp.com.au> | 2007-11-12 13:59:40 +1100 |
commit | 42b36cc0ce717deeb10030141a43dede763a3ebe (patch) | |
tree | b2dc48b4f16c5dc59461ad24b027d631edda1da4 /include/asm-sparc/poll.h | |
parent | 1200e646ae238afc536be70257290eb33fb6e364 (diff) |
virtio: Force use of power-of-two for descriptor ring sizes
The virtio descriptor rings of size N-1 were nicely set up to be
aligned to an N-byte boundary. But as Anthony Liguori points out, the
free-running indices used by virtio require that the sizes be a power
of 2, otherwise we get problems on wrap (demonstrated with lguest).
So we replace the clever "2^n-1" scheme with a simple "align to page
boundary" scheme: this means that all virtio rings take at least two
pages, but it's safer than guessing cache alignment.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'include/asm-sparc/poll.h')
0 files changed, 0 insertions, 0 deletions