Re: [PATCH v7 1/4] spinlock: A new lockref structure for locklessupdate of refcount

From: Linus Torvalds
Date: Tue Sep 03 2013 - 11:41:32 EST


On Tue, Sep 3, 2013 at 3:15 AM, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> One more thing to try would be a regular '-e cycles' non-PEBS run and see
> whether there's still largish overhead visible around that instruction.

I've done that, and it matches the PEBS runs, except obviously with
the instruction skew (so then depending on run it's 95% the
instruction after the xadd). So the PEBS profiles are entirely
consistent with other data.

Linus
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