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Date:   Fri, 19 Mar 2021 10:14:39 -0700
From:   Jacob Pan <jacob.jun.pan@linux.intel.com>
To:     Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        David Woodhouse <dwmw2@infradead.org>,
        iommu@lists.linux-foundation.org, cgroups@vger.kernel.org,
        Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Eric Auger <eric.auger@redhat.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Raj Ashok <ashok.raj@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>, Yi Liu <yi.l.liu@intel.com>,
        Wu Hao <hao.wu@intel.com>, Dave Jiang <dave.jiang@intel.com>,
        jacob.jun.pan@linux.intel.com
Subject: Re: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and
 allocation APIs
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Hi Jean-Philippe,

On Fri, 19 Mar 2021 10:58:41 +0100, Jean-Philippe Brucker
<jean-philippe@linaro.org> wrote:

> > Slightly off the title. As we are moving to use cgroup to limit PASID
> > allocations, it would be much simpler if we enforce on the current
> > task.  
> 
> Yes I think we should do that. Is there a problem with charging the
> process that does the PASID allocation even if the PASID indexes some
> other mm?
Besides complexity, my second concern is that we are sharing the misc
cgroup controller with other resources that do not have such behavior.

Cgroup v2 also has unified hierarchy which also requires coherent behavior
among controllers.

Thanks,

Jacob