> Subject: Re: arm-smmu-v3 high cpu usage for NVMe
>
> On 20/03/2020 10:41, John Garry wrote:
>
> + Barry, Alexandru
>
> > PerfTop: 85864 irqs/sec kernel:89.6% exact: 0.0% lost:
> > 0/34434 drop:
> > 0/40116 [4000Hz cycles], (all, 96 CPUs)
> >
>
The mapping operations of the Tegra SMMU driver are subjected to a race
condition issues because SMMU Address Space isn't allocated and freed
atomically, while it should be. This patch makes the mapping operations
atomic, it fixes an accidentally released Host1x Address Space problem
which happens
