Messages in this thread | | | Date | Thu, 8 May 2008 08:27:47 +0300 | From | "Pekka Enberg" <> | Subject | Re: [PATCH 08 of 11] anon-vma-rwsem |
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On Thu, May 8, 2008 at 8:20 AM, Andrea Arcangeli <andrea@qumranet.com> wrote: > Actually I looked both at the struct and at the slab alignment just in > case it was changed recently. Now after reading your mail I also > compiled it just in case. > > @@ -27,6 +27,7 @@ struct anon_vma { > struct anon_vma { > > spinlock_t lock; /* Serialize access to vma list */ > > struct list_head head; /* List of private "related" vmas */ > + int flag:1; > };
You might want to read carefully what Linus wrote:
> The one that already has a 4 byte padding thing on x86-64 just after the > spinlock? And that on 32-bit x86 (with less than 256 CPU's) would have two > bytes of padding if we didn't just make the spinlock type unconditionally > 32 bits rather than the 16 bits we actually _use_?
So you need to add the flag _after_ ->lock and _before_ ->head....
Pekka
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