Messages in this thread | | | Date | Thu, 12 Apr 2007 11:57:02 +1000 | From | Nick Piggin <> | Subject | Re: [PATCH, take4] FUTEX : new PRIVATE futexes |
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Eric Dumazet wrote: > On Wed, 11 Apr 2007 19:23:26 +1000 > Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>>>As this external thing certainly is not doing the check itself, to be on the safe side we should enforce it in get_futex_key(). I agree with you : If we want to maximize performance, we could say : The check *must* be done by the caller. >> >>Well we _control_ the API, so let's make it as clean and performant as possible >>from the start. > > > Take a look at do_futex(). > Adding checks in callers just increase code size. I tried this got only bad results. > This would speedup only the slow path (ie when some user code want to give us non aligned addrs) > A single factorized check is cleaner and not slower, since we reduce icache pressure.
1 extra check versus all that additional argument passing? I don't think it is conclusive.
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