Re: [PATCH 3/8] readahead: replace ra->mmap_miss with ra->ra_flags

From: Wu Fengguang
Date: Mon Nov 28 2011 - 22:42:26 EST


On Wed, Nov 23, 2011 at 12:31:50PM -0800, Andrew Morton wrote:
> On Wed, 23 Nov 2011 20:47:45 +0800
> Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote:
>
> > > should be ulong, which is compatible with the bitops.h code.
> > > Or perhaps we should use a bitfield and let the compiler do the work.
> >
> > What if we do
> >
> > u16 mmap_miss;
> > u16 ra_flags;
> >
> > That would get rid of this patch. I'd still like to pack the various
> > flags as well as pattern into one single ra_flags, which makes it
> > convenient to pass things around (as one single parameter).
>
> I'm not sure that this will improve things much...
>
> Again, how does the code look if you use a bitfield and let the
> compiler do the worK?

It results in much clean code, as you may find in the V2 patches :-)

Thanks,
Fengguang
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