On 05/01/2013 03:42 PM, David Rientjes wrote:
On Wed, 1 May 2013, Cody P Schafer wrote:
Signed-off-by: Cody P Schafer <cody@xxxxxxxxxxxxxxxxxx>
Nack, pgdat_resize_unlock() is unnecessary if irqs are known to be
disabled.
All this patch does is is indicate that rather than using node_size_lock
directly (as it won't be around without CONFIG_MEMORY_HOTPLUG), one should use
the pgdat_resize_[un]lock() helper macros.
I think that's obvious given the lock is surrounded by
#ifdef CONFIG_MEMORY_HOTPLUG. The fact remains that hotplug code need not
use pgdat_resize_lock() if irqs are disabled.
Obvious how? This comment is the documentation on how to handle locking
of pg_data_t, and doesn't mention pgdat_resize_lock() at all. Sure, a
newcomer would probably find pgdat_resize_lock() eventually, even more
so if they were interested in performance gains from not re-disabling
local irqs.
I don't see a convincing reason to omit relevant documentation and make
it more difficult to find the "right" way to do things.
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