Messages in this thread | | | From | Andrew Lutomirski <> | Date | Mon, 21 Apr 2014 18:06:19 -0700 | Subject | Re: [PATCH] x86-64: espfix for 64-bit mode *PROTOTYPE* |
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On Mon, Apr 21, 2014 at 5:53 PM, H. Peter Anvin <hpa@zytor.com> wrote: > Well, if 2^17 CPUs are allocated we might 2K pages allocated. We could easily do a bitmap here, of course. NR_CPUS/64 is a small number, and would reduce the code complexity. >
Even simpler: just get rid of the check entirely. That is, break out of the higher level loops once one of them is set (this should be a big speedup regardless) and don't allocate the page if the first PTE is already pointing at something.
After all, espfix_already_there is mostly a duplicate of init_espfix_cpu.
--Andy
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