tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git queue-5.7 head: 4b2c068f670ba180e3048703c477727032ac7ea3 commit: cb3321340b03a6b73698f794e4742250a5847473 [273/349] tipc: add test for Nagle algorithm effectiveness config: parisc-randconfig-r004-20200709 (attached as .config) compiler: hppa-linux-gcc (GCC) 9.3.0 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 git checkout cb3321340b03a6b73698f794e4742250a5847473 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc 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 >>): In file included from arch/parisc/include/asm/io.h:6, from include/linux/io.h:13, from include/linux/irq.h:20, from arch/parisc/include/asm/hardirq.h:13, from include/linux/hardirq.h:9, from include/net/sock.h:38, from net/tipc/msg.c:37: include/asm-generic/pgtable.h: In function 'pte_clear_not_present_full': arch/parisc/include/asm/pgtable.h:96:9: warning: variable 'old_pte' set but not used [-Wunused-but-set-variable] 96 | pte_t old_pte; \ | ^~~~~~~ arch/parisc/include/asm/pgtable.h:322:34: note: in expansion of macro 'set_pte_at' 322 | #define pte_clear(mm, addr, xp) set_pte_at(mm, addr, xp, __pte(0)) | ^~~~~~~~~~ include/asm-generic/pgtable.h:202:2: note: in expansion of macro 'pte_clear' 202 | pte_clear(mm, address, ptep); | ^~~~~~~~~ include/asm-generic/pgtable.h: In function '__ptep_modify_prot_commit': arch/parisc/include/asm/pgtable.h:96:9: warning: variable 'old_pte' set but not used [-Wunused-but-set-variable] 96 | pte_t old_pte; \ | ^~~~~~~ include/asm-generic/pgtable.h:641:2: note: in expansion of macro 'set_pte_at' 641 | set_pte_at(vma->vm_mm, addr, ptep, pte); | ^~~~~~~~~~ net/tipc/msg.c: In function 'tipc_msg_append': 215 | struct sk_buff *skb, *prev; | ^~~~ vim +/prev +215 net/tipc/msg.c 4f1688b2c63cd8 Jon Paul Maloy 2014-06-25 202 c0bceb97db9efc Jon Maloy 2019-10-30 203 /** c0bceb97db9efc Jon Maloy 2019-10-30 204 * tipc_msg_append(): Append data to tail of an existing buffer queue c0bceb97db9efc Jon Maloy 2019-10-30 205 * @hdr: header to be used c0bceb97db9efc Jon Maloy 2019-10-30 206 * @m: the data to be appended c0bceb97db9efc Jon Maloy 2019-10-30 207 * @mss: max allowable size of buffer c0bceb97db9efc Jon Maloy 2019-10-30 208 * @dlen: size of data to be appended c0bceb97db9efc Jon Maloy 2019-10-30 209 * @txq: queue to appand to c0bceb97db9efc Jon Maloy 2019-10-30 210 * Returns the number og 1k blocks appended or errno value c0bceb97db9efc Jon Maloy 2019-10-30 211 */ c0bceb97db9efc Jon Maloy 2019-10-30 212 int tipc_msg_append(struct tipc_msg *_hdr, struct msghdr *m, int dlen, c0bceb97db9efc Jon Maloy 2019-10-30 213 int mss, struct sk_buff_head *txq) c0bceb97db9efc Jon Maloy 2019-10-30 214 { c0bceb97db9efc Jon Maloy 2019-10-30 @215 struct sk_buff *skb, *prev; c0bceb97db9efc Jon Maloy 2019-10-30 216 int accounted, total, curr; c0bceb97db9efc Jon Maloy 2019-10-30 217 int mlen, cpy, rem = dlen; c0bceb97db9efc Jon Maloy 2019-10-30 218 struct tipc_msg *hdr; c0bceb97db9efc Jon Maloy 2019-10-30 219 c0bceb97db9efc Jon Maloy 2019-10-30 220 skb = skb_peek_tail(txq); c0bceb97db9efc Jon Maloy 2019-10-30 221 accounted = skb ? msg_blocks(buf_msg(skb)) : 0; c0bceb97db9efc Jon Maloy 2019-10-30 222 total = accounted; c0bceb97db9efc Jon Maloy 2019-10-30 223 379efd7d060a52 Tuong Lien 2020-06-03 224 do { c0bceb97db9efc Jon Maloy 2019-10-30 225 if (!skb || skb->len >= mss) { c0bceb97db9efc Jon Maloy 2019-10-30 226 prev = skb; c0bceb97db9efc Jon Maloy 2019-10-30 227 skb = tipc_buf_acquire(mss, GFP_KERNEL); c0bceb97db9efc Jon Maloy 2019-10-30 228 if (unlikely(!skb)) c0bceb97db9efc Jon Maloy 2019-10-30 229 return -ENOMEM; c0bceb97db9efc Jon Maloy 2019-10-30 230 skb_orphan(skb); c0bceb97db9efc Jon Maloy 2019-10-30 231 skb_trim(skb, MIN_H_SIZE); c0bceb97db9efc Jon Maloy 2019-10-30 232 hdr = buf_msg(skb); c0bceb97db9efc Jon Maloy 2019-10-30 233 skb_copy_to_linear_data(skb, _hdr, MIN_H_SIZE); c0bceb97db9efc Jon Maloy 2019-10-30 234 msg_set_hdr_sz(hdr, MIN_H_SIZE); c0bceb97db9efc Jon Maloy 2019-10-30 235 msg_set_size(hdr, MIN_H_SIZE); c0bceb97db9efc Jon Maloy 2019-10-30 236 __skb_queue_tail(txq, skb); c0bceb97db9efc Jon Maloy 2019-10-30 237 total += 1; c0bceb97db9efc Jon Maloy 2019-10-30 238 } c0bceb97db9efc Jon Maloy 2019-10-30 239 hdr = buf_msg(skb); c0bceb97db9efc Jon Maloy 2019-10-30 240 curr = msg_blocks(hdr); c0bceb97db9efc Jon Maloy 2019-10-30 241 mlen = msg_size(hdr); c0bceb97db9efc Jon Maloy 2019-10-30 242 cpy = min_t(int, rem, mss - mlen); c0bceb97db9efc Jon Maloy 2019-10-30 243 if (cpy != copy_from_iter(skb->data + mlen, cpy, &m->msg_iter)) c0bceb97db9efc Jon Maloy 2019-10-30 244 return -EFAULT; c0bceb97db9efc Jon Maloy 2019-10-30 245 msg_set_size(hdr, mlen + cpy); c0bceb97db9efc Jon Maloy 2019-10-30 246 skb_put(skb, cpy); c0bceb97db9efc Jon Maloy 2019-10-30 247 rem -= cpy; c0bceb97db9efc Jon Maloy 2019-10-30 248 total += msg_blocks(hdr) - curr; 379efd7d060a52 Tuong Lien 2020-06-03 249 } while (rem); c0bceb97db9efc Jon Maloy 2019-10-30 250 return total - accounted; c0bceb97db9efc Jon Maloy 2019-10-30 251 } c0bceb97db9efc Jon Maloy 2019-10-30 252 :::::: The code at line 215 was first introduced by commit :::::: c0bceb97db9efc72629dd00cd0d9812f24d4ba2d tipc: add smart nagle feature :::::: TO: Jon Maloy <jon.maloy(a)ericsson.com&gt; :::::: CC: David S. Miller <davem(a)davemloft.net&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org