Messages in this thread |  | | Date | Mon, 21 Jan 2013 01:40:41 +0000 | From | Christoph Lameter <> | Subject | Re: [RFC][PATCH v3] slub: Keep page and object in sync in slab_alloc_node() |
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On Fri, 18 Jan 2013, Eric Dumazet wrote:
> 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.
Yes on x86 the relocation and the fetch is just a single instruction and therefore no preemption can occur.
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