Messages in this thread | | | Date | Fri, 25 Nov 2022 16:49:23 +0100 | From | Johan Hovold <> | Subject | Re: [PATCH] arm64: dts: qcom: sc8280xp: fix PCIe DMA coherency |
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On Fri, Nov 25, 2022 at 08:23:36PM +0530, Manivannan Sadhasivam wrote: > On Fri, Nov 25, 2022 at 03:43:59PM +0100, Johan Hovold wrote: > > On Fri, Nov 25, 2022 at 07:56:25PM +0530, Manivannan Sadhasivam wrote: > > > On Thu, Nov 24, 2022 at 03:25:01PM +0100, Johan Hovold wrote:
> > I never claimed it would fix the problem, I explicitly wrote that it > > made it less likely to occur (to the point where my reproducer no longer > > triggers). > > > Increasing the buffer sizes to two pages to force CMA allocation also appears > > to make the problem go away. > > The "go away" part sounded like a claim to me and hence I added the statement. > But no worries :)
Hopefully it's clear enough if you also read the preceding sentence (with emphasis added):
presumably as these queues are small enough to not be allocated using CMA which in turn make them *more likely to be cached* (e.g. due to accesses to nearby pages through the cacheable linear map).
Johan
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