tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf/kprobes head: a70a04b3844f59c29573a8581d5c263225060dd6 commit: 666fab4a3ea143315a9c059fad9f3a0f1365d54b [24/25] Merge branch 'linus' into perf/kprobes config: mips-randconfig-r021-20201203 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 32c501dd88b62787d3a5ffda7aabcf4650dbe3cd) 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 mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=666fab4a3ea143315a9c059fad9f3a0f1365d54b git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git git fetch --no-tags tip perf/kprobes git checkout 666fab4a3ea143315a9c059fad9f3a0f1365d54b # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips
If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <[email protected]> All warnings (new ones prefixed by >>): In file included from include/linux/smp.h:13: In file included from include/linux/cpumask.h:13: In file included from include/linux/atomic.h:7: arch/mips/include/asm/atomic.h:257:1: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] ATOMIC_SIP_OP(atomic, int, subu, ll, sc) ^ arch/mips/include/asm/atomic.h:251:7: note: expanded from macro 'ATOMIC_SIP_OP' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:24: In file included from include/linux/module.h:13: In file included from include/linux/stat.h:19: In file included from include/linux/time.h:73: In file included from include/linux/time32.h:13: In file included from include/linux/timex.h:65: In file included from arch/mips/include/asm/timex.h:19: In file included from arch/mips/include/asm/cpu-type.h:12: In file included from include/linux/smp.h:13: In file included from include/linux/cpumask.h:13: In file included from include/linux/atomic.h:7: arch/mips/include/asm/atomic.h:261:1: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] ATOMIC_SIP_OP(atomic64, s64, dsubu, lld, scd) ^ arch/mips/include/asm/atomic.h:251:7: note: expanded from macro 'ATOMIC_SIP_OP' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:24: In file included from include/linux/module.h:13: In file included from include/linux/stat.h:19: In file included from include/linux/time.h:73: In file included from include/linux/time32.h:13: In file included from include/linux/timex.h:65: In file included from arch/mips/include/asm/timex.h:19: In file included from arch/mips/include/asm/cpu-type.h:12: In file included from include/linux/smp.h:15: In file included from include/linux/smp_types.h:5: include/linux/llist.h:237:9: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] return xchg(&head->first, NULL); ^ arch/mips/include/asm/cmpxchg.h:102:7: note: expanded from macro 'xchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:24: In file included from include/linux/module.h:16: In file included from include/linux/kmod.h:9: In file included from include/linux/umh.h:4: In file included from include/linux/gfp.h:6: In file included from include/linux/mmzone.h:16: In file included from include/linux/seqlock.h:19: In file included from include/linux/mutex.h:21: include/linux/debug_locks.h:17:9: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] return xchg(&debug_locks, 0); ^ arch/mips/include/asm/cmpxchg.h:102:7: note: expanded from macro 'xchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:29: In file included from include/linux/mm.h:33: In file included from include/linux/pgtable.h:6: arch/mips/include/asm/pgtable.h:208:3: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] cmpxchg64(&buddy->pte, 0, _PAGE_GLOBAL); ^ arch/mips/include/asm/cmpxchg.h:220:2: note: expanded from macro 'cmpxchg64' cmpxchg((ptr), (o), (n)); \ ^ arch/mips/include/asm/cmpxchg.h:194:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:29: In file included from include/linux/mm.h:33: In file included from include/linux/pgtable.h:6: arch/mips/include/asm/pgtable.h:208:3: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] arch/mips/include/asm/cmpxchg.h:220:2: note: expanded from macro 'cmpxchg64' cmpxchg((ptr), (o), (n)); \ ^ arch/mips/include/asm/cmpxchg.h:204:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:31: In file included from include/linux/fb.h:5: In file included from include/linux/kgdb.h:19: In file included from include/linux/kprobes.h:31: >> include/linux/freelist.h:52:8: warning: converting the result of '<<' to a >> boolean always evaluates to true [-Wtautological-constant-compare] if (!try_cmpxchg_release(&list->head, &head, node)) { ^ include/linux/atomic-fallback.h:113:9: note: expanded from macro 'try_cmpxchg_release' ___r = cmpxchg_release((_ptr), ___o, (_new)); \ ^ include/linux/atomic-fallback.h:36:25: note: expanded from macro 'cmpxchg_release' #define cmpxchg_release cmpxchg ^ arch/mips/include/asm/cmpxchg.h:194:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:31: In file included from include/linux/fb.h:5: In file included from include/linux/kgdb.h:19: In file included from include/linux/kprobes.h:31: >> include/linux/freelist.h:52:8: warning: converting the result of '<<' to a >> boolean always evaluates to true [-Wtautological-constant-compare] include/linux/atomic-fallback.h:113:9: note: expanded from macro 'try_cmpxchg_release' ___r = cmpxchg_release((_ptr), ___o, (_new)); \ ^ include/linux/atomic-fallback.h:36:25: note: expanded from macro 'cmpxchg_release' #define cmpxchg_release cmpxchg ^ arch/mips/include/asm/cmpxchg.h:204:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:31: In file included from include/linux/fb.h:5: In file included from include/linux/kgdb.h:19: In file included from include/linux/kprobes.h:31: include/linux/freelist.h:99:7: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] if (try_cmpxchg_acquire(&list->head, &head, next)) { ^ include/linux/atomic-fallback.h:102:9: note: expanded from macro 'try_cmpxchg_acquire' ___r = cmpxchg_acquire((_ptr), ___o, (_new)); \ ^ include/linux/atomic-fallback.h:35:25: note: expanded from macro 'cmpxchg_acquire' #define cmpxchg_acquire cmpxchg ^ arch/mips/include/asm/cmpxchg.h:194:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/s1d13xxxfb.c:31: In file included from include/linux/fb.h:5: In file included from include/linux/kgdb.h:19: In file included from include/linux/kprobes.h:31: include/linux/freelist.h:99:7: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] include/linux/atomic-fallback.h:102:9: note: expanded from macro 'try_cmpxchg_acquire' ___r = cmpxchg_acquire((_ptr), ___o, (_new)); \ ^ include/linux/atomic-fallback.h:35:25: note: expanded from macro 'cmpxchg_acquire' #define cmpxchg_acquire cmpxchg ^ arch/mips/include/asm/cmpxchg.h:204:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ 16 warnings generated. -- In file included from include/linux/smp.h:13: In file included from include/linux/cpumask.h:13: In file included from include/linux/atomic.h:7: arch/mips/include/asm/atomic.h:257:1: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] ATOMIC_SIP_OP(atomic, int, subu, ll, sc) ^ arch/mips/include/asm/atomic.h:251:7: note: expanded from macro 'ATOMIC_SIP_OP' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:14: In file included from include/linux/module.h:13: In file included from include/linux/stat.h:19: In file included from include/linux/time.h:73: In file included from include/linux/time32.h:13: In file included from include/linux/timex.h:65: In file included from arch/mips/include/asm/timex.h:19: In file included from arch/mips/include/asm/cpu-type.h:12: In file included from include/linux/smp.h:13: In file included from include/linux/cpumask.h:13: In file included from include/linux/atomic.h:7: arch/mips/include/asm/atomic.h:261:1: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] ATOMIC_SIP_OP(atomic64, s64, dsubu, lld, scd) ^ arch/mips/include/asm/atomic.h:251:7: note: expanded from macro 'ATOMIC_SIP_OP' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:14: In file included from include/linux/module.h:13: In file included from include/linux/stat.h:19: In file included from include/linux/time.h:73: In file included from include/linux/time32.h:13: In file included from include/linux/timex.h:65: In file included from arch/mips/include/asm/timex.h:19: In file included from arch/mips/include/asm/cpu-type.h:12: In file included from include/linux/smp.h:15: In file included from include/linux/smp_types.h:5: include/linux/llist.h:237:9: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] return xchg(&head->first, NULL); ^ arch/mips/include/asm/cmpxchg.h:102:7: note: expanded from macro 'xchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:14: In file included from include/linux/module.h:16: In file included from include/linux/kmod.h:9: In file included from include/linux/umh.h:4: In file included from include/linux/gfp.h:6: In file included from include/linux/mmzone.h:16: In file included from include/linux/seqlock.h:19: In file included from include/linux/mutex.h:21: include/linux/debug_locks.h:17:9: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] return xchg(&debug_locks, 0); ^ arch/mips/include/asm/cmpxchg.h:102:7: note: expanded from macro 'xchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:22: In file included from include/linux/mm.h:33: In file included from include/linux/pgtable.h:6: arch/mips/include/asm/pgtable.h:208:3: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] cmpxchg64(&buddy->pte, 0, _PAGE_GLOBAL); ^ arch/mips/include/asm/cmpxchg.h:220:2: note: expanded from macro 'cmpxchg64' cmpxchg((ptr), (o), (n)); \ ^ arch/mips/include/asm/cmpxchg.h:194:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:22: In file included from include/linux/mm.h:33: In file included from include/linux/pgtable.h:6: arch/mips/include/asm/pgtable.h:208:3: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] arch/mips/include/asm/cmpxchg.h:220:2: note: expanded from macro 'cmpxchg64' cmpxchg((ptr), (o), (n)); \ ^ arch/mips/include/asm/cmpxchg.h:204:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:34: In file included from include/linux/fb.h:5: In file included from include/linux/kgdb.h:19: In file included from include/linux/kprobes.h:31: >> include/linux/freelist.h:52:8: warning: converting the result of '<<' to a >> boolean always evaluates to true [-Wtautological-constant-compare] if (!try_cmpxchg_release(&list->head, &head, node)) { ^ include/linux/atomic-fallback.h:113:9: note: expanded from macro 'try_cmpxchg_release' ___r = cmpxchg_release((_ptr), ___o, (_new)); \ ^ include/linux/atomic-fallback.h:36:25: note: expanded from macro 'cmpxchg_release' #define cmpxchg_release cmpxchg ^ arch/mips/include/asm/cmpxchg.h:194:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:34: In file included from include/linux/fb.h:5: In file included from include/linux/kgdb.h:19: In file included from include/linux/kprobes.h:31: >> include/linux/freelist.h:52:8: warning: converting the result of '<<' to a >> boolean always evaluates to true [-Wtautological-constant-compare] include/linux/atomic-fallback.h:113:9: note: expanded from macro 'try_cmpxchg_release' ___r = cmpxchg_release((_ptr), ___o, (_new)); \ ^ include/linux/atomic-fallback.h:36:25: note: expanded from macro 'cmpxchg_release' #define cmpxchg_release cmpxchg ^ arch/mips/include/asm/cmpxchg.h:204:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:34: In file included from include/linux/fb.h:5: In file included from include/linux/kgdb.h:19: In file included from include/linux/kprobes.h:31: include/linux/freelist.h:99:7: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] if (try_cmpxchg_acquire(&list->head, &head, next)) { ^ include/linux/atomic-fallback.h:102:9: note: expanded from macro 'try_cmpxchg_acquire' ___r = cmpxchg_acquire((_ptr), ___o, (_new)); \ ^ include/linux/atomic-fallback.h:35:25: note: expanded from macro 'cmpxchg_acquire' #define cmpxchg_acquire cmpxchg ^ arch/mips/include/asm/cmpxchg.h:194:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ In file included from drivers/video/fbdev/core/fbmem.c:34: In file included from include/linux/fb.h:5: In file included from include/linux/kgdb.h:19: In file included from include/linux/kprobes.h:31: include/linux/freelist.h:99:7: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] include/linux/atomic-fallback.h:102:9: note: expanded from macro 'try_cmpxchg_acquire' ___r = cmpxchg_acquire((_ptr), ___o, (_new)); \ ^ include/linux/atomic-fallback.h:35:25: note: expanded from macro 'cmpxchg_acquire' #define cmpxchg_acquire cmpxchg ^ arch/mips/include/asm/cmpxchg.h:204:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) \ ^ arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ drivers/video/fbdev/core/fbmem.c:736:36: warning: unused variable 'proc_fb_seq_ops' [-Wunused-const-variable] static const struct seq_operations proc_fb_seq_ops = { ^ 17 warnings generated. vim +52 include/linux/freelist.h e563604a5f5a891 Peter Zijlstra 2020-08-29 29 e563604a5f5a891 Peter Zijlstra 2020-08-29 30 static inline void __freelist_add(struct freelist_node *node, struct freelist_head *list) e563604a5f5a891 Peter Zijlstra 2020-08-29 31 { e563604a5f5a891 Peter Zijlstra 2020-08-29 32 /* e563604a5f5a891 Peter Zijlstra 2020-08-29 33 * Since the refcount is zero, and nobody can increase it once it's e563604a5f5a891 Peter Zijlstra 2020-08-29 34 * zero (except us, and we run only one copy of this method per node at e563604a5f5a891 Peter Zijlstra 2020-08-29 35 * a time, i.e. the single thread case), then we know we can safely e563604a5f5a891 Peter Zijlstra 2020-08-29 36 * change the next pointer of the node; however, once the refcount is e563604a5f5a891 Peter Zijlstra 2020-08-29 37 * back above zero, then other threads could increase it (happens under e563604a5f5a891 Peter Zijlstra 2020-08-29 38 * heavy contention, when the refcount goes to zero in between a load e563604a5f5a891 Peter Zijlstra 2020-08-29 39 * and a refcount increment of a node in try_get, then back up to e563604a5f5a891 Peter Zijlstra 2020-08-29 40 * something non-zero, then the refcount increment is done by the other e563604a5f5a891 Peter Zijlstra 2020-08-29 41 * thread) -- so if the CAS to add the node to the actual list fails, e563604a5f5a891 Peter Zijlstra 2020-08-29 42 * decrese the refcount and leave the add operation to the next thread e563604a5f5a891 Peter Zijlstra 2020-08-29 43 * who puts the refcount back to zero (which could be us, hence the e563604a5f5a891 Peter Zijlstra 2020-08-29 44 * loop). e563604a5f5a891 Peter Zijlstra 2020-08-29 45 */ e563604a5f5a891 Peter Zijlstra 2020-08-29 46 struct freelist_node *head = READ_ONCE(list->head); e563604a5f5a891 Peter Zijlstra 2020-08-29 47 e563604a5f5a891 Peter Zijlstra 2020-08-29 48 for (;;) { e563604a5f5a891 Peter Zijlstra 2020-08-29 49 WRITE_ONCE(node->next, head); e563604a5f5a891 Peter Zijlstra 2020-08-29 50 atomic_set_release(&node->refs, 1); e563604a5f5a891 Peter Zijlstra 2020-08-29 51 e563604a5f5a891 Peter Zijlstra 2020-08-29 @52 if (!try_cmpxchg_release(&list->head, &head, node)) { e563604a5f5a891 Peter Zijlstra 2020-08-29 53 /* e563604a5f5a891 Peter Zijlstra 2020-08-29 54 * Hmm, the add failed, but we can only try again when e563604a5f5a891 Peter Zijlstra 2020-08-29 55 * the refcount goes back to zero. e563604a5f5a891 Peter Zijlstra 2020-08-29 56 */ e563604a5f5a891 Peter Zijlstra 2020-08-29 57 if (atomic_fetch_add_release(REFS_ON_FREELIST - 1, &node->refs) == 1) e563604a5f5a891 Peter Zijlstra 2020-08-29 58 continue; e563604a5f5a891 Peter Zijlstra 2020-08-29 59 } e563604a5f5a891 Peter Zijlstra 2020-08-29 60 return; e563604a5f5a891 Peter Zijlstra 2020-08-29 61 } e563604a5f5a891 Peter Zijlstra 2020-08-29 62 } e563604a5f5a891 Peter Zijlstra 2020-08-29 63 :::::: The code at line 52 was first introduced by commit :::::: e563604a5f5a891283b6a8db4001cee833a7c6b8 freelist: Implement lockless freelist :::::: TO: Peter Zijlstra <[email protected]> :::::: CC: Ingo Molnar <[email protected]> --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/[email protected]
.config.gz
Description: application/gzip
