Re: [PATCH 04/15] mm/huge_memory: use new hashtable implementation

[Sasha Levin <sasha.levin@oracle.com>]

On 12/20/2012 03:28 PM, David Rientjes wrote:
> On Wed, 19 Dec 2012, Sasha Levin wrote:
> 
>> In this case, the downside is that you'll waste 8KB if hugepages aren't available,
>> but the upside is that you'll have one less dereference when accessing the
>> hashtable.
>>
>> If the 8KB saving is preferable here I'll drop the patch and come back when
>> dynamic hashtable is supported.
>>
> 
> If a distro releases with CONFIG_TRANSPARNET_HUGEPAGE=y and a user is 
> running on a processor that does not support pse then this just cost them 
> 8KB for no reason.  The overhead by simply enabling 
> CONFIG_TRANSPARENT_HUGEPAGE is worse in this scenario, but this is whole 
> reason for having the dynamic allocation in the original code.  If there's 
> a compelling reason for why we want this change, then that fact should at 
> least be documented.
> 
> Could you propose a v2 that includes fixes for the other problems that 
> were mentioned?
> 

Sure, will do.


Thanks,
Sasha

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