Re: [PATCH v3 2/2] iommu/amd: Add basic debugfs infrastructure for AMD IOMMU

[Gary R Hook]

On 04/17/2018 12:38 PM, Hook, Gary wrote:
> On 4/13/2018 8:08 PM, Mehta, Sohil wrote:
> > On Fri, 2018-04-06 at 08:17 -0500, Gary R Hook wrote:
> > > +
> > > +
> > > +ÂÂÂ mutex_lock(&amd_iommu_debugfs_lock);
> > > +ÂÂÂ if (!amd_iommu_debugfs) {
> > > +ÂÂÂÂÂÂÂ d_top = iommu_debugfs_setup();
> > > +ÂÂÂÂÂÂÂ if (d_top)
> > > +ÂÂÂÂÂÂÂÂÂÂÂ amd_iommu_debugfs =
> > > debugfs_create_dir("amd", d_top);
> > > +ÂÂÂ }
> > > +ÂÂÂ mutex_unlock(&amd_iommu_debugfs_lock);
> >
> >
> > You can do the above only once if you iterate over the IOMMUs here
> > ÂÂinstead of doing it inÂamd_iommu_init.
>
> I'm not sure it matters, given the finite number of IOMMUs in a system, 
> and the fact that this work is done exactly once. However, removal of a 
> lock is fine thing, so I'll move this around.

After thinking about this, and looking at the code, I've decided to 
leave this alone.

v4 is on its way.