> On 25 Oct 2016, at 12:15, Paul Mackerras <pau...@ozlabs.org> wrote: > > On Tue, Oct 25, 2016 at 11:24:34AM +0800, Li Zhong wrote: >> The core_idle_lock_held loops when the lock bit is held by others. >> However, it is possible that after the lock bit is cleared, some one >> else sees it first and sets the lock bit. And lwarx loads a value with >> lock bit set, and the lock bit may be cleared in the following stwcx. >> It is possible the first one is still executing in the critical section. >> >> This patch rechecks the lock bit after lwarx, and go back to loop if it >> is set. > > You're quite correct, in fact I posted almost exactly the same patch a > few days ago... See http://patchwork.ozlabs.org/patch/684963/.
Forget to check the list before sending … One minor difference, maybe we can use bne- for the rechecking :) Thanks, Zhong > > Thanks, > Paul. >
