Re: [PATCH net-2.6.26 1/2] Shrink size of net_device by filling alignment holes in it.

[Eric Dumazet <dada1@cosmosbay.com>]

Eric Dumazet a écrit :
> Pavel Emelyanov a écrit :
>> I've found a much easier way to shrink the net_device structure 
>> rather that moving all the operations out of it. However, since
>> the net_device may grow further, moving the operations into a
>> separate place may look reasonable.
>>
>> The pahole tool showed, that there are a 124 and 80 bytes holes
>> before the queue_lock and the _xmit_lock respectively. Moving most
>> of the devices callbacks into the 2nd hole makes the sizeof of the
>> structure be 1024 bytes.
>>
>>   
> On 32 bits platform and CONFIG_X86_L1_CACHE_SHIFT=7
> I presume :)
>
> Could you check if x86_64 machines with  X86_L1_CACHE_SHIFT = 7 or 8 
> dont suffer from this patch ?
>
> At first glance I would say it seems OK, but this net_device is really 
> touchy for SMP performance :)
I meant :

X86_L1_CACHE_SHIFT = 6 (MK8 | MCORE2)  or 7 (others)