Re: [PATCH/RFC 10/11] Shared Policy: per cpuset shared file policy control

[Lee Schermerhorn <Lee.Schermerhorn@hp.com>]

On Wed, 2007-06-27 at 12:52 -0700, Paul Jackson wrote:
> > If my patches eventually go in, I'd agree with this.  I was trying to be
> > a good doobee and not add code that wasn't needed.
> 
> The ifdef's are added code -- added source code.
> 
> For a body of code that's as big as the Linux kernel, and changing
> at the speed of Andrew's Enter key, I worry more about keeping the
> source code as easy to read as possible, than I do about the last
> few bytes of kernel text size.

Point taken.
> 
> The success of Linux is far more constrained by the limitations of
> human neurons than by the limitations of dynamic RAM chips.
> 
> > 	[[ ! -f $cpuset/shared_file_policy ]] || echo 1 >$cpuset/...
> 
> Sure - you can code that - that 'shared_file_policy' file is your baby,
> and you know how best to care for it.
> 
> But it leads to others writing code that doesn't have this [[ ! -f
> ... ]] guard, which code works fine ... for a while.  Works long
> enough to get good and buried in three layers of cruft, leading to
> a problem costing someone hours or days to unravel, when it finally
> hits a machine lacking that file.
> 
> I'd sure like to see that ifdef gone.  I wish I had the time now to
> go stamp out that other ifdef in kernel/cpuset.c as well.

Well, I'm sure I've got a few more spins to go on this patch set ;-).  I
can easily just remove the ifdefs and see what folks think.  I'll need
to add a couple of conditionally defined functions/macros to handle the
update/test of "shared_file_policy_enabled" when the system is
configured w/o NUMA.  The resulting #ifdefs will be in the header.  Are
you "OK" with that?

Lee

> 

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