Messages in this thread | | | Date | Fri, 06 Jan 2012 10:50:07 +0000 | From | "Jan Beulich" <> | Subject | Re: x86-64: memset()/memcpy() not fully standards compliant |
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>>> On 06.01.12 at 11:37, Andi Kleen <andi@firstfloor.org> wrote: >> > You would slow a critical fast path operation down for something >> > that never happens?!? >> >> It does happen, just (so far) not in-tree. It's a latent problem that's >> just waiting for someone else to run into. Apart from large bootmem >> allocations (where not even the latency of the memory clearing > > Modern kernels are bootmem less.
It's not the traditional bootmem implementation anymore, but alloc_bootmem() et al still exist, and still clear the allocated memory (in __alloc_memory_core_early()). So there is a code path that can validly be used (and it is this code path that is presenting one of the problems with the non-pv-ops Xen kernels, as they're using flatmem rather than sparsemem since their physical address space is always fully continuous).
Jan
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