Messages in this thread |  | | Date | Fri, 14 Feb 2014 09:30:39 -0800 | From | "Paul E. McKenney" <> | Subject | Re: Memory allocator semantics |
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On Tue, Feb 11, 2014 at 12:43:35PM -0600, Christoph Lameter wrote: > On Tue, 11 Feb 2014, Pekka Enberg wrote: > > > So again, there's nothing in (A) that the memory allocator is > > concerned about. kmalloc() makes no guarantees whatsoever about the > > visibility of "r1" across CPUs. If you're saying that there's an > > implicit barrier between kmalloc() and kfree(), that's an unintended > > side-effect, not a design decision AFAICT. > > I am not sure that this side effect necessarily happens. The SLUB fastpath > does not disable interrupts and only uses a cmpxchg without lock > semantics.
That tells me what I need to know. Users should definitely not try a "drive-by kfree()" of something that was concurrently allocated. ;-)
Thanx, Paul
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