Messages in this thread | | | Date | Fri, 10 Sep 2021 15:17:04 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/4] sched/wakeup: Strengthen current_save_and_set_rtlock_wait_state() |
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On Fri, Sep 10, 2021 at 01:57:26PM +0100, Will Deacon wrote: > On Thu, Sep 09, 2021 at 04:27:46PM +0200, Peter Zijlstra wrote: > > Moo yes, so the earlier changelog I wrote was something like: > > > > current_save_and_set_rtlock_wait_state(); > > for (;;) { > > if (try_lock()) > > break; > > > > raw_spin_unlock_irq(&lock->wait_lock); > > if (!cond) > > schedule(); > > raw_spin_lock_irq(&lock->wait_lock); > > > > set_current_state(TASK_RTLOCK_WAIT); > > } > > current_restore_rtlock_saved_state(); > > > > which is more what the code looks like before these patches, and in that > > case the @cond load can be lifted before __state. > > Ah, so that makes more sense, thanks. I can't see how the try_lock() could > be reordered though, as it's going to have to do an atomic rmw.
OK, lemme go update the Changelog and make it __flags for bigeasy :-)
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