Messages in this thread | | | From | "Ma, Xindong" <> | Subject | RE: Add memory barrier when waiting on futex | Date | Wed, 27 Nov 2013 00:28:22 +0000 |
| |
> -----Original Message----- > From: Peter Zijlstra [mailto:peterz@infradead.org] > Sent: Tuesday, November 26, 2013 4:26 PM > To: Ma, Xindong > Cc: stable@vger.kernel.org; stable-commits@vger.kernel.org; Wysocki, Rafael > J; ccross@google.com; tglx@linutronix.de; dvhart@linux.intel.com; > mingo@kernel.org; linux-kernel@vger.kernel.org; gregkh@linuxfoundation.org; > 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.
| |