:::::: :::::: Manual check reason: "low confidence static check warning: mm/page_alloc.c:3094:4: warning: Value stored to 'batch' is never read [clang-analyzer-deadcode.DeadStores]" ::::::
CC: [email protected] BCC: [email protected] TO: [email protected] tree: https://android.googlesource.com/kernel/common android13-5.15 head: d1b6bd094bc2cd055ef96969867f232a079ab965 commit: 37b2d597bb542ea753f4f11604ce2c35868271ba [2/3] ANDROID: mm: add cma pcp list :::::: branch date: 29 hours ago :::::: commit date: 7 months ago config: x86_64-randconfig-c007 (https://download.01.org/0day-ci/archive/20220605/[email protected]/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project b364c76683f8ef241025a9556300778c07b590c2) 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 remote add android-common https://android.googlesource.com/kernel/common git fetch --no-tags android-common android13-5.15 git checkout 37b2d597bb542ea753f4f11604ce2c35868271ba # save the config file COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <[email protected]> clang-analyzer warnings: (new ones prefixed by >>) __cmp(unique_x, unique_y, op); }) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/minmax.h:28:26: note: expanded from macro '__cmp' #define __cmp(x, y, op) ((x) op (y) ? (x) : (y)) ^~~ mm/page_alloc.c:1458:10: note: '?' condition is false count = min(pcp->count, count); ^ include/linux/minmax.h:45:19: note: expanded from macro 'min' #define min(x, y) __careful_cmp(x, y, <) ^ include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp' __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) ^ include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once' __cmp(unique_x, unique_y, op); }) ^ include/linux/minmax.h:28:26: note: expanded from macro '__cmp' #define __cmp(x, y, op) ((x) op (y) ? (x) : (y)) ^ mm/page_alloc.c:1459:9: note: Assuming 'count' is <= 0 while (count > 0) { ^~~~~~~~~ mm/page_alloc.c:1459:2: note: Loop condition is false. Execution continues on line 1513 while (count > 0) { ^ mm/page_alloc.c:1526:2: note: Left side of '&&' is false list_for_each_entry_safe(page, tmp, &head, lru) { ^ include/linux/list.h:715:13: note: expanded from macro 'list_for_each_entry_safe' for (pos = list_first_entry(head, typeof(*pos), member), \ ^ include/linux/list.h:522:2: note: expanded from macro 'list_first_entry' list_entry((ptr)->next, type, member) ^ include/linux/list.h:511:2: note: expanded from macro 'list_entry' container_of(ptr, type, member) ^ include/linux/kernel.h:495:61: note: expanded from macro 'container_of' BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ ^ mm/page_alloc.c:1526:2: note: Taking false branch list_for_each_entry_safe(page, tmp, &head, lru) { ^ include/linux/list.h:715:13: note: expanded from macro 'list_for_each_entry_safe' for (pos = list_first_entry(head, typeof(*pos), member), \ ^ include/linux/list.h:522:2: note: expanded from macro 'list_first_entry' list_entry((ptr)->next, type, member) ^ include/linux/list.h:511:2: note: expanded from macro 'list_entry' container_of(ptr, type, member) ^ note: (skipping 2 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all) include/linux/compiler_types.h:322:2: note: expanded from macro 'compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ include/linux/compiler_types.h:310:2: note: expanded from macro '_compiletime_assert' __compiletime_assert(condition, msg, prefix, suffix) ^ include/linux/compiler_types.h:302:3: note: expanded from macro '__compiletime_assert' if (!(condition)) \ ^ mm/page_alloc.c:1526:2: note: Loop condition is false. Exiting loop list_for_each_entry_safe(page, tmp, &head, lru) { ^ include/linux/list.h:715:13: note: expanded from macro 'list_for_each_entry_safe' for (pos = list_first_entry(head, typeof(*pos), member), \ ^ include/linux/list.h:522:2: note: expanded from macro 'list_first_entry' list_entry((ptr)->next, type, member) ^ include/linux/list.h:511:2: note: expanded from macro 'list_entry' container_of(ptr, type, member) ^ note: (skipping 2 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all) include/linux/compiler_types.h:322:2: note: expanded from macro 'compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ include/linux/compiler_types.h:310:2: note: expanded from macro '_compiletime_assert' __compiletime_assert(condition, msg, prefix, suffix) ^ include/linux/compiler_types.h:300:2: note: expanded from macro '__compiletime_assert' do { \ ^ mm/page_alloc.c:1526:2: note: Assigned value is garbage or undefined list_for_each_entry_safe(page, tmp, &head, lru) { ^ include/linux/list.h:716:7: note: expanded from macro 'list_for_each_entry_safe' n = list_next_entry(pos, member); \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/list.h:555:2: note: expanded from macro 'list_next_entry' list_entry((pos)->member.next, typeof(*(pos)), member) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/list.h:511:2: note: expanded from macro 'list_entry' container_of(ptr, type, member) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/kernel.h:494:2: note: expanded from macro 'container_of' void *__mptr = (void *)(ptr); \ ^ ~~~~~~~~~~~~~ >> mm/page_alloc.c:3094:4: warning: Value stored to 'batch' is never read >> [clang-analyzer-deadcode.DeadStores] batch = max(batch >> order, 2); ^ mm/page_alloc.c:3094:4: note: Value stored to 'batch' is never read mm/page_alloc.c:5348:29: warning: Array access (from variable 'page_array') results in a null pointer dereference [clang-analyzer-core.NullDereference] page_array[nr_populated] = page; ~~~~~~~~~~ ^ mm/page_alloc.c:5255:9: note: Assuming 'page_array' is null while (page_array && nr_populated < nr_pages && page_array[nr_populated]) ^~~~~~~~~~ mm/page_alloc.c:5255:20: note: Left side of '&&' is false while (page_array && nr_populated < nr_pages && page_array[nr_populated]) ^ mm/page_alloc.c:5259:15: note: Assuming 'nr_pages' is > 0 if (unlikely(nr_pages <= 0)) ^ include/linux/compiler.h:78:42: note: expanded from macro 'unlikely' # define unlikely(x) __builtin_expect(!!(x), 0) ^ mm/page_alloc.c:5259:2: note: Taking false branch if (unlikely(nr_pages <= 0)) ^ mm/page_alloc.c:5263:15: note: 'page_array' is null if (unlikely(page_array && nr_pages - nr_populated == 0)) ^ include/linux/compiler.h:78:42: note: expanded from macro 'unlikely' # define unlikely(x) __builtin_expect(!!(x), 0) ^ mm/page_alloc.c:5263:26: note: Left side of '&&' is false if (unlikely(page_array && nr_pages - nr_populated == 0)) ^ mm/page_alloc.c:5263:2: note: Taking false branch if (unlikely(page_array && nr_pages - nr_populated == 0)) ^ mm/page_alloc.c:5267:27: note: Left side of '&&' is false if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT)) ^ mm/page_alloc.c:5271:6: note: Assuming the condition is false if (nr_pages - nr_populated == 1) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/page_alloc.c:5271:2: note: Taking false branch if (nr_pages - nr_populated == 1) ^ mm/page_alloc.c:5289:2: note: Taking false branch if (!prepare_alloc_pages(gfp, 0, preferred_nid, nodemask, &ac, &alloc_gfp, &alloc_flags)) ^ mm/page_alloc.c:5294:2: note: Loop condition is true. Entering loop body for_each_zone_zonelist_nodemask(zone, z, ac.zonelist, ac.highest_zoneidx, ac.nodemask) { ^ include/linux/mmzone.h:1199:2: note: expanded from macro 'for_each_zone_zonelist_nodemask' for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ ^ mm/page_alloc.c:5297:25: note: Left side of '&&' is false if (cpusets_enabled() && (alloc_flags & ALLOC_CPUSET) && ^ mm/page_alloc.c:5302:7: note: Nr_online_nodes is <= 1 if (nr_online_nodes > 1 && zone != ac.preferred_zoneref->zone && ^ include/linux/nodemask.h:490:26: note: expanded from macro 'nr_online_nodes' #define nr_online_nodes 1U ^~ mm/page_alloc.c:5302:27: note: Left side of '&&' is false if (nr_online_nodes > 1 && zone != ac.preferred_zoneref->zone && ^ mm/page_alloc.c:5308:3: note: Taking true branch if (zone_watermark_fast(zone, 0, mark, ^ mm/page_alloc.c:5311:4: note: Execution continues on line 5319 break; ^ mm/page_alloc.c:5319:16: note: 'zone' is non-null if (unlikely(!zone)) ^ include/linux/compiler.h:78:42: note: expanded from macro 'unlikely' # define unlikely(x) __builtin_expect(!!(x), 0) ^ mm/page_alloc.c:5319:2: note: Taking false branch if (unlikely(!zone)) ^ mm/page_alloc.c:5323:2: note: Loop condition is false. Exiting loop local_lock_irqsave(&pagesets.lock, flags); ^ include/linux/local_lock.h:31:2: note: expanded from macro 'local_lock_irqsave' __local_lock_irqsave(lock, flags) ^ include/linux/local_lock_internal.h:79:3: note: expanded from macro '__local_lock_irqsave' local_irq_save(flags); \ ^ include/linux/irqflags.h:214:3: note: expanded from macro 'local_irq_save' raw_local_irq_save(flags); \ ^ include/linux/irqflags.h:169:2: note: expanded from macro 'raw_local_irq_save' do { \ ^ mm/page_alloc.c:5323:2: note: Taking false branch local_lock_irqsave(&pagesets.lock, flags); ^ include/linux/local_lock.h:31:2: note: expanded from macro 'local_lock_irqsave' __local_lock_irqsave(lock, flags) ^ include/linux/local_lock_internal.h:79:3: note: expanded from macro '__local_lock_irqsave' vim +/batch +3094 mm/page_alloc.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 3070 37b2d597bb542e Chris Goldsworthy 2020-11-16 3071 /* 37b2d597bb542e Chris Goldsworthy 2020-11-16 3072 * Return the pcp list that corresponds to the migrate type if that list isn't 37b2d597bb542e Chris Goldsworthy 2020-11-16 3073 * empty. 37b2d597bb542e Chris Goldsworthy 2020-11-16 3074 * If the list is empty return NULL. 37b2d597bb542e Chris Goldsworthy 2020-11-16 3075 */ 37b2d597bb542e Chris Goldsworthy 2020-11-16 3076 static struct list_head *get_populated_pcp_list(struct zone *zone, 37b2d597bb542e Chris Goldsworthy 2020-11-16 3077 unsigned int order, struct per_cpu_pages *pcp, 37b2d597bb542e Chris Goldsworthy 2020-11-16 3078 int migratetype, unsigned int alloc_flags) 37b2d597bb542e Chris Goldsworthy 2020-11-16 3079 { 37b2d597bb542e Chris Goldsworthy 2020-11-16 3080 struct list_head *list = &pcp->lists[order_to_pindex(migratetype, order)]; 37b2d597bb542e Chris Goldsworthy 2020-11-16 3081 37b2d597bb542e Chris Goldsworthy 2020-11-16 3082 if (list_empty(list)) { 37b2d597bb542e Chris Goldsworthy 2020-11-16 3083 int batch = READ_ONCE(pcp->batch); 37b2d597bb542e Chris Goldsworthy 2020-11-16 3084 int alloced; 37b2d597bb542e Chris Goldsworthy 2020-11-16 3085 37b2d597bb542e Chris Goldsworthy 2020-11-16 3086 /* 37b2d597bb542e Chris Goldsworthy 2020-11-16 3087 * Scale batch relative to order if batch implies 37b2d597bb542e Chris Goldsworthy 2020-11-16 3088 * free pages can be stored on the PCP. Batch can 37b2d597bb542e Chris Goldsworthy 2020-11-16 3089 * be 1 for small zones or for boot pagesets which 37b2d597bb542e Chris Goldsworthy 2020-11-16 3090 * should never store free pages as the pages may 37b2d597bb542e Chris Goldsworthy 2020-11-16 3091 * belong to arbitrary zones. 37b2d597bb542e Chris Goldsworthy 2020-11-16 3092 */ 37b2d597bb542e Chris Goldsworthy 2020-11-16 3093 if (batch > 1) 37b2d597bb542e Chris Goldsworthy 2020-11-16 @3094 batch = max(batch >> order, 2); 37b2d597bb542e Chris Goldsworthy 2020-11-16 3095 alloced = rmqueue_bulk(zone, order, pcp->batch, list, migratetype, alloc_flags); 37b2d597bb542e Chris Goldsworthy 2020-11-16 3096 37b2d597bb542e Chris Goldsworthy 2020-11-16 3097 pcp->count += alloced << order; 37b2d597bb542e Chris Goldsworthy 2020-11-16 3098 if (list_empty(list)) 37b2d597bb542e Chris Goldsworthy 2020-11-16 3099 list = NULL; 37b2d597bb542e Chris Goldsworthy 2020-11-16 3100 } 37b2d597bb542e Chris Goldsworthy 2020-11-16 3101 return list; 37b2d597bb542e Chris Goldsworthy 2020-11-16 3102 } 37b2d597bb542e Chris Goldsworthy 2020-11-16 3103 -- 0-DAY CI Kernel Test Service https://01.org/lkp _______________________________________________ kbuild mailing list -- [email protected] To unsubscribe send an email to [email protected]
