On Tue 24 Jan 2023 at 21:42, Jakub Kicinski <kuba@xxxxxxxxxx> wrote: > On Tue, 24 Jan 2023 15:02:06 +0100 Vlad Buslov wrote: >> Modify the offload algorithm of UDP connections to the following: >> >> - Offload NEW connection as unidirectional. >> >> - When connection state changes to ESTABLISHED also update the hardware >> flow. However, in order to prevent act_ct from spamming offload add wq for >> every packet coming in reply direction in this state verify whether >> connection has already been updated to ESTABLISHED in the drivers. If that >> it the case, then skip flow_table and let conntrack handle such packets >> which will also allow conntrack to potentially promote the connection to >> ASSURED. >> >> - When connection state changes to ASSURED set the flow_table flow >> NF_FLOW_HW_BIDIRECTIONAL flag which will cause refresh mechanism to offload >> the reply direction. >> >> All other protocols have their offload algorithm preserved and are always >> offloaded as bidirectional. >> >> Note that this change tries to minimize the load on flow_table add >> workqueue. First, it tracks the last ctinfo that was offloaded by using new >> flow 'ext_data' field and doesn't schedule the refresh for reply direction >> packets when the offloads have already been updated with current ctinfo. >> Second, when 'add' task executes on workqueue it always update the offload >> with current flow state (by checking 'bidirectional' flow flag and >> obtaining actual ctinfo/cookie through meta action instead of caching any >> of these from the moment of scheduling the 'add' work) preventing the need >> from scheduling more updates if state changed concurrently while the 'add' >> work was pending on workqueue. > > Clang is not happy: > > net/sched/act_ct.c:677:12: warning: cast to smaller integer type 'enum ip_conntrack_info' from 'typeof (_Generic((flow->ext_data), char: (char)0, unsigned char: (unsigned char)0, signed char: (signed char)0, unsigned short: (unsigned short)0, short: (short)0, unsigned int: (unsigned int)0, int: (int)0, unsigned long: (unsigned long)0, long: (long)0, unsigned long long: (unsigned long long)0, long long: (long long)0, default: (flow->ext_data)))' (aka 'void *') [-Wvoid-pointer-to-enum-cast] > else if ((enum ip_conntrack_info)READ_ONCE(flow->ext_data) == > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Thanks, will fix it in v5.
