On 04/01/2016 10:55 AM, Eric Dumazet wrote: > On Fri, 2016-04-01 at 10:13 +0800, Jason Wang wrote: > > >> The problem is we want to support busy polling for tun. This needs >> napi_id to be passed to tun socket by sk_mark_napi_id() during >> tun_net_xmit(). But before reaching this, XPS will set sender_cpu will >> make us can't see correct napi_id. >> > Looks like napi_id should have precedence then ?
But then when busy polling is enabled, we may still hit the issue before commit 2bd82484bb4c5db1d5dc983ac7c409b2782e0154? So looks like sometimes (e.g for tun), we need both two fields. > > Only forwarding should allow the field to be cleared to allow XPS to do > its job. > > Maybe skb_sender_cpu_clear() was removed too early (commit > 64d4e3431e686dc37ce388ba531c4c4e866fb141) Not sure I get you, but this will clear napi_id too. > Look, it is 8pm here, I am pretty sure a solution can be found, > but I am also need to take a break, I started at 3am today... > > >
