On 22-07-25, 15:46, Dmitry Baryshkov wrote: > On Tue, Jul 22, 2025 at 05:50:08PM +0530, Jyothi Kumar Seerapu wrote: > > On 7/19/2025 3:27 PM, Dmitry Baryshkov wrote: > > > On Mon, Jul 07, 2025 at 09:58:30PM +0530, Jyothi Kumar Seerapu wrote: > > > > On 7/4/2025 1:11 AM, Dmitry Baryshkov wrote: > > > > > On Thu, 3 Jul 2025 at 15:51, Jyothi Kumar Seerapu
[Folks, would be nice to trim replies] > > > > Could you please confirm if can go with the similar approach of unmap > > > > the > > > > processed TREs based on a fixed threshold or constant value, instead of > > > > unmapping them all at once? > > > > > > I'd still say, that's a bad idea. Please stay within the boundaries of > > > the DMA API. > > > > > I agree with the approach you suggested—it's the GPI's responsibility to > > manage the available TREs. > > > > However, I'm curious whether can we set a dynamic watermark value perhaps > > half the available TREs) to trigger unmapping of processed TREs ? This would > > allow the software to prepare the next set of TREs while the hardware > > continues processing the remaining ones, enabling better parallelism and > > throughput. > > Let's land the simple implementation first, which can then be improved. > However I don't see any way to return 'above the watermark' from the DMA > controller. You might need to enhance the API. Traditionally, we set the dma transfers for watermark level and we get a interrupt. So you might want to set the callback for watermark level and then do mapping/unmapping etc in the callback. This is typical model for dmaengines, we should follow that well BR -- ~Vinod
