Messages in this thread |  | | Date | Tue, 12 Jul 2011 13:53:55 -0500 (CDT) | | From | Christoph Lameter <> | | Subject | Re: [slubllv7 06/17] slub: Add cmpxchg_double_slab() |
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On Tue, 12 Jul 2011, H. Peter Anvin wrote:
> On 07/12/2011 09:47 AM, Christoph Lameter wrote: > > On Tue, 12 Jul 2011, Eric Dumazet wrote: > > > >> Le mardi 12 juillet 2011 à 10:59 -0500, Christoph Lameter a écrit : > >> > >>> We do not need to have _count included. This is just there because the > >>> field is in the way on 64 bit and we can only do 2x 64 bit cmpxchges. On > >>> 32 bi we can drop _count from "counters". > >> > >> OK, thanks for clarification. > > > > Still I'd like to get some ideas on how to make the whole thing much > > cleaner. Isnt there some way to convert a struct to an unsigned long > > without going through a union? And a way to convert a struct + 32 bit > > atomic_t into a 64 bit unsigned long? Would simplify things significantly. > > If you know it is in memory you can cast ("pun") the pointer.
Well I use a page struct on the stack now to put the information in memory and then use the union to cast it.
> If it's not in memory that can be inefficient, though.
Yeah. Isnt there some C trick to cast a word size struct to unsigned long?
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