Re: [PATCH] Cpuset: rcu optimization of page alloc hook

[Paul Jackson]

> Please do use __read_mostly for new kmem_cache :
> 
> static kmem_cache_t *cpuset_cache __read_mostly;

Is there any downside to this?  I ask because accesses through
this 'cpuset_cache' pointer are rather infrequent - only when
the sysadmin or the batch scheduler is creating or removing
cpusets, which for the purposes of 'back of the envelope'
estimates, might be once a minute or less.  Further, it is
not at all a performance critical path.

So I really don't give a dang if it takes a few milliseconds
to pick up this pointer, at least so far as cpusets matters.

That said, would you still advise marking this __read_mostly?


Andrew wrote:
> We've been shuffling towards removing kmem_cache_t in favour of `struct
> kmem_cache',

So I suppose what I should really have is:

  static struct kmem_cache *cpuset_cache __read_mostly;

??

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@xxxxxxx> 1.925.600.0401
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/