Re: [PATCH] net: Add back alignment for size for __alloc_skb

From: Eric Dumazet
Date: Wed Nov 02 2011 - 19:21:11 EST


On 03/11/2011 00:19, Tony Lindgren wrote:

> * David Miller <davem@xxxxxxxxxxxxx> [111102 15:42]:
>> c>
>>> The issue is calculation of skb->end, which is based upon calculated
>>> 'size' variable.
>>>
>>> skb->end determines alignment of skb_shared_info, which is where the
>>> alignment problem is occuring for Tony.
>>
>> Right, and SMP_CACHE_BYTES setting should save us in any case.
>>
>> For ARM, SMP_CACHE_BYTES seems to be set to L1_CACHE_BYTES which in
>> turn is set via ARM_L1_CACHE_SHIFT which can be set seemingly to any
>> value but the defaults are 5 and 6 which should be OK.
>>
>> So unless Tony is using a non-standard setting of ARM_L1_CACHE_SHIFT,
>> this report is a bit mysterious.
>
> This is happening at least with omap1_defconfig. In that case we have
> ARM_L1_CACHE_SHIFT=5.
>
> Regards,
>
> Tony


Do you use SLOB, SLUB or SLAB ?

Thanks

--
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/