On Tue, May 31, 2022 at 7:02 PM Allen Pais <apais@xxxxxxxxxxxxxxxxxxx> wrote: [note: something is wrong with your email client, your previous reply appears to be in HTML] > > That is a good idea, lot of drivers are waiting for completion which can > > be signalled from hardirq, this would also reduce the hops we have and > > help improve latency a bit. On the downside, some controllers provide > > error information, which would need to be dealt with. > > > I am not an expert in dma subsystem, but by using completion from > Hardirq context be a concern? Especially with latency. I don't see how: to the task waiting for the completion, there should be no difference, and for the irq handler sending it, it just avoids a few cycles going into softirq context. > > Yes that would be a very reasonable mechanism, thanks for the > > suggestions. > > I have started working on the idea of global softirq. A RFC should be ready > For review soon. Ok, thanks! Arnd