Messages in this thread | | | Date | Sat, 4 Sep 2021 18:19:27 +0800 | From | Boqun Feng <> | Subject | Re: [RFC] locking: rwbase: Take care of ordering guarantee for fastpath reader |
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On Sat, Sep 04, 2021 at 12:14:29PM +0200, Peter Zijlstra wrote: > On Fri, Sep 03, 2021 at 10:50:58PM +0800, Boqun Feng wrote: > > > * ordering, either is strong enough to provide ACQUIRE order > > > * for the above load of @readers. > > > */ > > > rwbase_set_and_save_current_state(state); > > > raw_spin_lock_irqsave(&rtm->wait_lock, flags); > > > > > > while (readers) { > > > ... > > > readers = atomic_read(&rwb->readers); > > > > The above should be _acquire(), right? Pairs with the last reader > > exiting the critical section and dec ->readers to 0. If so, it > > undermines the necessity of the restructure? > > This is the one that's followed by set_current_state(), no?
You're right. I was missing that ;-/
Regards, Boqun
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