Re: [PATCH 1/4] iommu/arm-smmu-v3: Use command queue batching helpers to improve performance

From: Will Deacon
Date: Mon Aug 16 2021 - 04:21:38 EST

On Mon, Aug 16, 2021 at 03:47:58PM +0800, Leizhen (ThunderTown) wrote:
> On 2021/8/16 15:24, John Garry wrote:
> >> In addition, I find that function arm_smmu_cmdq_build_cmd() can also be optimized
> >> slightly, three useless instructions can be reduced.
> >
> > I think that you could optimise further by pre-building commonly used commands.
> >
> > For example, CMD_SYNC without MSI polling is always the same. And then only different in 1 field for MSI polling.
> >
> > But you need to check if the performance gain is worth the change.
> Good advice. I can give it a try.

Please send it as a new patch on top. I've queued the old one and sent
it to Joerg. Since this is just further cleanup, it can be done separately.