random: reorder struct entropy_store to remove padding on 64bits
in [Kernel]
|
Prev: mmotm 2010-07-27-14-56 uploaded (staging/iio)
Next: x86: Add memory modify constraints to xchg() and cmpxchg()
From: Matt Mackall on 28 Jul 2010 12:10 On Wed, 2010-07-28 at 10:32 +0100, Richard Kennedy wrote: > Re-order structure entropy_store to remove 8 bytes of padding on > 64 bit builds, so shrinking this structure from 72 to 64 bytes > and allowing it to fit into one cache line. I have a vague memory that we reordered things so that the r/w bits would be on a separate cache line than the r/o bits. But as we never added the alignment primitives to actually enforce that, I guess it doesn't matter much. > Signed-off-by: Richard Kennedy <richard(a)rsk.demon.co.uk> Signed-off-by: Matt Mackall <mpm(a)selenic.com> -- Mathematics is the supreme nostalgia of our time. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Matt Mackall on 31 Jul 2010 09:40
On Sat, 2010-07-31 at 19:58 +0800, Herbert Xu wrote: > On Wed, Jul 28, 2010 at 11:02:28AM -0500, Matt Mackall wrote: > > On Wed, 2010-07-28 at 10:32 +0100, Richard Kennedy wrote: > > > Re-order structure entropy_store to remove 8 bytes of padding on > > > 64 bit builds, so shrinking this structure from 72 to 64 bytes > > > and allowing it to fit into one cache line. > > > > I have a vague memory that we reordered things so that the r/w bits > > would be on a separate cache line than the r/o bits. But as we never > > added the alignment primitives to actually enforce that, I guess it > > doesn't matter much. > > > > > Signed-off-by: Richard Kennedy <richard(a)rsk.demon.co.uk> > > > > Signed-off-by: Matt Mackall <mpm(a)selenic.com> > > Patch applied. Thanks! Oops, I forgot to cc: you on this and Andrew queued it. Andrew, I've been queueing the RNG bits through Herbert's crypto tree lately. -- Mathematics is the supreme nostalgia of our time. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |