Hi Paolo, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on mptcp/export] [also build test WARNING on kselftest/next linus/master v5.14-rc1 next-20210713] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Paolo-Abeni/mptcp-refactor-activ... base: https://github.com/multipath-tcp/mptcp_net-next.git export config: x86_64-randconfig-r006-20210713 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 8d69635ed9ecf36fd0ca85906bfde17949671cbe) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://github.com/0day-ci/linux/commit/bc57ec20ec19b4d0b6de45ef1df8c8c36... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Paolo-Abeni/mptcp-refactor-active-backup/20210714-051541 git checkout bc57ec20ec19b4d0b6de45ef1df8c8c3685c7fe2 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): if (!tcp_rtx_and_write_queues_empty(ssk)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ net/mptcp/pm_netlink.c:931:8: note: uninitialized use occurs here if (push) ^~~~ net/mptcp/pm_netlink.c:924:4: note: remove the 'if' if its condition is always true if (!tcp_rtx_and_write_queues_empty(ssk)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ net/mptcp/pm_netlink.c:911:17: note: initialize the variable 'push' to silence this warning bool slow, push; ^ = 0 1 warning generated. vim +924 net/mptcp/pm_netlink.c 903 904 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk) 905 { 906 struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk); 907 struct sock *sk = (struct sock *)msk; 908 unsigned int active_max_loss_cnt; 909 struct net *net = sock_net(sk); 910 unsigned int stale_loss_cnt; 911 bool slow, push; 912 913 stale_loss_cnt = mptcp_stale_loss_cnt(net); 914 if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt) 915 return; 916 917 /* look for another available subflow not in loss state */ 918 active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1); 919 mptcp_for_each_subflow(msk, iter) { 920 if (iter != subflow && mptcp_subflow_active(iter) && 921 iter->stale_count < active_max_loss_cnt) { 922 /* we have some alteratives, try to mark this subflow as idle ...*/ 923 slow = lock_sock_fast(ssk); 925 subflow->stale = 1; 926 push = __mptcp_retransmit_pending_data(sk); 927 } 928 unlock_sock_fast(ssk, slow); 929 930 /* pending data on the idle subflow: retransmit */ 931 if (push) 932 __mptcp_push_pending(sk, 0); 933 return; 934 } 935 } 936 } 937 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org