> -----Original Message----- > From: Peter Zijlstra [mailto:peterz@xxxxxxxxxxxxx] > Sent: Tuesday, November 26, 2013 4:26 PM > To: Ma, Xindong > Cc: stable@xxxxxxxxxxxxxxx; stable-commits@xxxxxxxxxxxxxxx; Wysocki, Rafael > J; ccross@xxxxxxxxxx; tglx@xxxxxxxxxxxxx; dvhart@xxxxxxxxxxxxxxx; > mingo@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; > Tu, Xiaobing > Subject: Re: Add memory barrier when waiting on futex > > On Tue, Nov 26, 2013 at 01:07:25AM +0000, Ma, Xindong wrote: > > I've already aware that they've protected by spinlock, this is why I adding a > memory barrier to fix it. > > That doesn't make sense.. the spinlocks should provide the required > serialization, there's nothing to fix. > > > I reproduced this issue several times on android which running on IA dual > core. > > I think you need to be more specific, in particular, if spinlocks do not provide > serialization on your IA32 device, I'd call that thing broken. > Adding random memory barriers is _WRONG_. > I agree with you. Thanks, Peter. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html