Re: [PATCH net-next v4 0/4] Add support to do threaded napi busy poll
From: Samiullah Khawaja <hidden>
Date: 2025-03-27 19:35:42
On Thu, Mar 27, 2025 at 11:40 AM Joe Damato [off-list ref] wrote:
On Wed, Mar 26, 2025 at 02:57:37PM -0700, Stanislav Fomichev wrote:quoted
On 03/26, Samiullah Khawaja wrote:quoted
On Tue, Mar 25, 2025 at 10:47 AM Martin Karsten [off-list ref] wrote:quoted
On 2025-03-25 12:40, Samiullah Khawaja wrote:quoted
On Sun, Mar 23, 2025 at 7:38 PM Martin Karsten [off-list ref] wrote:quoted
On 2025-03-20 22:15, Samiullah Khawaja wrote:quoted
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Nice catch. It seems a recent change broke the busy polling for AF_XDP and there was a fix for the XDP_ZEROCOPY but the XDP_COPY remained broken and seems in my experiments I didn't pick that up. During my experimentation I confirmed that all experiment modes are invoking the busypoll and not going through softirqs. I confirmed this through perf traces. I sent out a fix for XDP_COPY busy polling here in the link below. I will resent this for the net since the original commit has already landed in 6.13. https://lore.kernel.org/netdev/CAAywjhSEjaSgt7fCoiqJiMufGOi=oxa164_vTfk+3P43H60qwQ@mail.gmail.com/T/#t (local)In general, when sending the patches and numbers, try running everything against the latest net-next. Otherwise, it is very confusing to reason about..I had mentioned in my previous review, but worth mentioning again... using --base=auto when using format-patch to generate the base commit SHA would be really useful to potentially help avoid this problem.
I completely agree. But I have 2 platforms that I am working with, virito-net and idpf. I use idpf to generate experiment data but I cannot use the latest kernel with it since the AF_XDP support for it is broken. And I generate patches using format-patch after rebasing on top of net-next and doing functional testing with qemu. This is to make sure that the patches don't have any conflicts with the latest net-next.