Hi Gregory, kernel test robot noticed the following build warnings: [auto build test WARNING on akpm-mm/mm-everything] [also build test WARNING on deller-parisc/for-next powerpc/next powerpc/fixes s390/features jcmvbkbc-xtensa/xtensa-for-next arnd-asm-generic/master linus/master v6.7-rc4 next-20231208] [cannot apply to tip/x86/asm geert-m68k/for-next geert-m68k/for-linus] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Gregory-Price/mm-mempolicy-implement-the-sysfs-based-weighted_interleave-interface/20231209-150314 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20231209065931.3458-3-gregory.price%40memverge.com patch subject: [PATCH v2 02/11] mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted interleaving config: x86_64-rhel-8.3-rust (https://download.01.org/0day-ci/archive/20231210/202312100543.ix4jxw81-lkp@xxxxxxxxx/config) compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231210/202312100543.ix4jxw81-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202312100543.ix4jxw81-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> mm/mempolicy.c:2355:3: warning: variable 'weight_total' is uninitialized when used here [-Wuninitialized] weight_total += weight; ^~~~~~~~~~~~ mm/mempolicy.c:2341:27: note: initialize the variable 'weight_total' to silence this warning unsigned int weight_total; ^ = 0 1 warning generated. vim +/weight_total +2355 mm/mempolicy.c 2329 2330 static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, 2331 struct mempolicy *pol, unsigned long nr_pages, 2332 struct page **page_array) 2333 { 2334 struct task_struct *me = current; 2335 unsigned long total_allocated = 0; 2336 unsigned long nr_allocated; 2337 unsigned long rounds; 2338 unsigned long node_pages, delta; 2339 unsigned char weight; 2340 unsigned char weights[MAX_NUMNODES]; 2341 unsigned int weight_total; 2342 unsigned long rem_pages = nr_pages; 2343 nodemask_t nodes = pol->nodes; 2344 int nnodes, node, prev_node; 2345 int i; 2346 2347 /* Stabilize the nodemask on the stack */ 2348 barrier(); 2349 2350 nnodes = nodes_weight(nodes); 2351 2352 /* Collect weights and save them on stack so they don't change */ 2353 for_each_node_mask(node, nodes) { 2354 weight = iw_table[node]; > 2355 weight_total += weight; 2356 weights[node] = weight; 2357 } 2358 2359 /* Continue allocating from most recent node and adjust the nr_pages */ 2360 if (pol->wil.cur_weight) { 2361 node = next_node_in(me->il_prev, nodes); 2362 node_pages = pol->wil.cur_weight; 2363 if (node_pages > rem_pages) 2364 node_pages = rem_pages; 2365 nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages, 2366 NULL, page_array); 2367 page_array += nr_allocated; 2368 total_allocated += nr_allocated; 2369 /* if that's all the pages, no need to interleave */ 2370 if (rem_pages <= pol->wil.cur_weight) { 2371 pol->wil.cur_weight -= rem_pages; 2372 return total_allocated; 2373 } 2374 /* Otherwise we adjust nr_pages down, and continue from there */ 2375 rem_pages -= pol->wil.cur_weight; 2376 pol->wil.cur_weight = 0; 2377 prev_node = node; 2378 } 2379 2380 /* Now we can continue allocating as if from 0 instead of an offset */ 2381 rounds = rem_pages / weight_total; 2382 delta = rem_pages % weight_total; 2383 for (i = 0; i < nnodes; i++) { 2384 node = next_node_in(prev_node, nodes); 2385 weight = weights[node]; 2386 node_pages = weight * rounds; 2387 if (delta) { 2388 if (delta > weight) { 2389 node_pages += weight; 2390 delta -= weight; 2391 } else { 2392 node_pages += delta; 2393 delta = 0; 2394 } 2395 } 2396 /* We may not make it all the way around */ 2397 if (!node_pages) 2398 break; 2399 /* If an over-allocation would occur, floor it */ 2400 if (node_pages + total_allocated > nr_pages) { 2401 node_pages = nr_pages - total_allocated; 2402 delta = 0; 2403 } 2404 nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages, 2405 NULL, page_array); 2406 page_array += nr_allocated; 2407 total_allocated += nr_allocated; 2408 prev_node = node; 2409 } 2410 2411 /* 2412 * Finally, we need to update me->il_prev and pol->wil.cur_weight 2413 * if there were overflow pages, but not equivalent to the node 2414 * weight, set the cur_weight to node_weight - delta and the 2415 * me->il_prev to the previous node. Otherwise if it was perfect 2416 * we can simply set il_prev to node and cur_weight to 0 2417 */ 2418 if (node_pages) { 2419 me->il_prev = prev_node; 2420 node_pages %= weight; 2421 pol->wil.cur_weight = weight - node_pages; 2422 } else { 2423 me->il_prev = node; 2424 pol->wil.cur_weight = 0; 2425 } 2426 2427 return total_allocated; 2428 } 2429 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
