Messages in this thread |  | | From | Thomas Gleixner <> | Subject | Re: [PATCH] locking/rtmutex: remove unused cmpxchg_relaxed | Date | Fri, 31 Jan 2020 21:23:01 +0100 |
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Davidlohr Bueso <dave@stgolabs.net> writes: > On Tue, 21 Jan 2020, Alex Shi wrote:
Subject: locking/rtmutex: remove unused cmpxchg_relaxed
should be
Subject: locking/rtmutex: Remove unused rt_mutex_cmpxchg_relaxed()
You're not removing cmpxchg_relaxed, right?
>> No one use this macro after it was introduced. Better to remove it?
Please make that factual.
The macro was never used at all. Remove it.
> You also need to remove it for the CONFIG_DEBUG_RT_MUTEXES=y case.
Yes.
> Hmm unrelated, but do we want CCAS for rtmutex fastpath? Ie: > > (l->owner == c && cmpxchg_acquire(&l->owner, c, n) == c) > > That would optimize for the contended case and avoid the cmpxchg - it would > also help if we ever do the top-waiter spin thing.
Not sure if it buys much, but it kinda makes sense.
Thanks,
tglx
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