Hello, On 04/26/2010 09:22 AM, Pekka Enberg wrote: > On Mon, Apr 26, 2010 at 9:59 AM, Zhang, Yanmin > <[email protected]> wrote: >>> I haven't been able to reproduce this either on my Core 2 machine. >> Mostly, the regression exists on Nehalem machines. I suspect it's related to >> hyper-threading machine. > > OK, so does anyone know why hyper-threading would change things for > the per-CPU allocator?
My wild speculation is that previously the cpu_slub structures of two neighboring threads ended up on the same cacheline by accident thanks to the back to back allocation. W/ the percpu allocator, this no longer would happen as the allocator groups percpu data together per-cpu. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
