[RFC] Improving scalability of smp_mb__[before|after]_clear_bit

Russell King - ARM Linux linux at arm.linux.org.uk
Tue Jul 19 06:59:37 EDT 2011

On Tue, Jul 19, 2011 at 11:43:08AM +0100, Russell King - ARM Linux wrote:
> On Tue, Jul 12, 2011 at 12:34:59AM -0700, heechul Yun wrote:
> > I think L2 cache sync operation, called by mb(), is not necessary for bitops.
> > This patch improves lat_pagefault of lmbench by up to 11% on a A9 SMP.
> > Higher proceesor
> > counts can benefit more.
> bitops should only be used on normal memory and not for stuff used for IO,
> so this should be safe.
> Could you submit it to the patch system please with Catalins ack?

Oh, you have but yet again the patch is broken by tabs converted to

$ pdb getpatch 6998/1 | tr ' ' '.'

If you can't fix your mail client not to do this, the patch system gives
you another way to submit - via the web interface where you can simply
attach the patch as a file.  That will avoid any messing about with your
mail client.

However, you really should get your mail client fixed so that it doesn't
mess up whitespace in patches.

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