Re: [RFC][PATCH v3] slub: Keep page and object in sync inslab_alloc_node()

[Eric Dumazet]

On Fri, 2013-01-18 at 18:40 +0000, Christoph Lameter wrote:

> The fetching of the tid is the only critical thing here. If the tid is
> retrieved from the right cpu then the cmpxchg will fail if any changes
> occured to freelist or the page variable.
> 
> The tid can be retrieved without disabling preemption through
> this_cpu_read().

Strictly speaking, this_cpu_read() _does_ disable preemption.

Of course, on x86, this_cpu_read() uses __this_cpu_read()



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