Hi Alice, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue.git dev-queue head: 0499ed813d995f0a1b97e5e59ff7fd864d8ffb62 commit: ac1fe751555b417952104c2a5f09592c0348c40d [91/92] iecm: Add iecm to the kernel build system config: alpha-allyesconfig (attached as .config) compiler: alpha-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 ac1fe751555b417952104c2a5f09592c0348c40d # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/net/ethernet/intel/iecm/iecm_txrx.c: In function 'iecm_rx_can_reuse_page': 2462 | if (rx_buf->page_offset > last_offset) | ^~~~~~~~~~~ | page_offset drivers/net/ethernet/intel/iecm/iecm_txrx.c:2462:28: note: each undeclared identifier is reported only once for each function it appears in vim +2462 drivers/net/ethernet/intel/iecm/iecm_txrx.c 2158dc66f3a92d Alice Michael 2020-07-14 2436 2158dc66f3a92d Alice Michael 2020-07-14 2437 /** 2158dc66f3a92d Alice Michael 2020-07-14 2438 * iecm_rx_can_reuse_page - Determine if page can be reused for another Rx 2158dc66f3a92d Alice Michael 2020-07-14 2439 * @rx_buf: buffer containing the page 2158dc66f3a92d Alice Michael 2020-07-14 2440 * 2158dc66f3a92d Alice Michael 2020-07-14 2441 * If page is reusable, we have a green light for calling iecm_reuse_rx_page, 2158dc66f3a92d Alice Michael 2020-07-14 2442 * which will assign the current buffer to the buffer that next_to_alloc is 2158dc66f3a92d Alice Michael 2020-07-14 2443 * pointing to; otherwise, the DMA mapping needs to be destroyed and 2158dc66f3a92d Alice Michael 2020-07-14 2444 * page freed 2158dc66f3a92d Alice Michael 2020-07-14 2445 */ 2158dc66f3a92d Alice Michael 2020-07-14 2446 static bool iecm_rx_can_reuse_page(struct iecm_rx_buf *rx_buf) 2158dc66f3a92d Alice Michael 2020-07-14 2447 { 8aa91340983bdc Alice Michael 2020-07-14 2448 #if (PAGE_SIZE >= 8192) 8aa91340983bdc Alice Michael 2020-07-14 2449 #endif 8aa91340983bdc Alice Michael 2020-07-14 2450 unsigned int pagecnt_bias = rx_buf->pagecnt_bias; 8aa91340983bdc Alice Michael 2020-07-14 2451 struct page *page = rx_buf->page; 8aa91340983bdc Alice Michael 2020-07-14 2452 8aa91340983bdc Alice Michael 2020-07-14 2453 /* avoid re-using remote pages */ 8aa91340983bdc Alice Michael 2020-07-14 2454 if (unlikely(iecm_rx_page_is_reserved(page))) 8aa91340983bdc Alice Michael 2020-07-14 2455 return false; 8aa91340983bdc Alice Michael 2020-07-14 2456 8aa91340983bdc Alice Michael 2020-07-14 2457 #if (PAGE_SIZE < 8192) 8aa91340983bdc Alice Michael 2020-07-14 2458 /* if we are only owner of page we can reuse it */ 8aa91340983bdc Alice Michael 2020-07-14 2459 if (unlikely((page_count(page) - pagecnt_bias) > 1)) 8aa91340983bdc Alice Michael 2020-07-14 2460 return false; 8aa91340983bdc Alice Michael 2020-07-14 2461 #else 8aa91340983bdc Alice Michael 2020-07-14 @2462 if (rx_buf->page_offset > last_offset) 8aa91340983bdc Alice Michael 2020-07-14 2463 return false; 8aa91340983bdc Alice Michael 2020-07-14 2464 #endif /* PAGE_SIZE < 8192) */ 8aa91340983bdc Alice Michael 2020-07-14 2465 8aa91340983bdc Alice Michael 2020-07-14 2466 /* If we have drained the page fragment pool we need to update 8aa91340983bdc Alice Michael 2020-07-14 2467 * the pagecnt_bias and page count so that we fully restock the 8aa91340983bdc Alice Michael 2020-07-14 2468 * number of references the driver holds. 8aa91340983bdc Alice Michael 2020-07-14 2469 */ 8aa91340983bdc Alice Michael 2020-07-14 2470 if (unlikely(pagecnt_bias == 1)) { 8aa91340983bdc Alice Michael 2020-07-14 2471 page_ref_add(page, USHRT_MAX - 1); 8aa91340983bdc Alice Michael 2020-07-14 2472 rx_buf->pagecnt_bias = USHRT_MAX; 8aa91340983bdc Alice Michael 2020-07-14 2473 } 8aa91340983bdc Alice Michael 2020-07-14 2474 8aa91340983bdc Alice Michael 2020-07-14 2475 return true; 2158dc66f3a92d Alice Michael 2020-07-14 2476 } 2158dc66f3a92d Alice Michael 2020-07-14 2477 :::::: The code at line 2462 was first introduced by commit :::::: 8aa91340983bdcd6861be0aad259c5b1d14584fb iecm: Add splitq TX/RX :::::: TO: Alice Michael <alice.michael(a)intel.com&gt; :::::: CC: Tony Nguyen <anthony.l.nguyen(a)intel.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org