Messages in this thread | | | Date | Wed, 02 Nov 2011 19:22:14 -0400 (EDT) | Subject | Re: [PATCH] net: Add back alignment for size for __alloc_skb | From | David Miller <> |
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From: Tony Lindgren <tony@atomide.com> Date: Wed, 2 Nov 2011 16:19:17 -0700
> * David Miller <davem@davemloft.net> [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.
Ok, so ksize(x) gives an odd value for whichever allocator you are using. Which is the point Eric was trying to make. It becomes clearernow.
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