On Thu, Jul 16, 2020 at 11:19:41AM +0100, Will Deacon wrote: > On Tue, Jun 23, 2020 at 01:28:36AM +0800, John Garry wrote: > > As mentioned in [0], the CPU may consume many cycles processing > > arm_smmu_cmdq_issue_cmdlist(). One issue we find is the cmpxchg() loop to > > get space on the queue takes approx 25% of the cycles for this function. > > > > This series removes that cmpxchg(). > > How about something much simpler like the diff below?
Ah, scratch that, I don't drop the lock if we fail the cas with it held. Let me hack it some more (I have no hardware so I can only build-test this). Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
