CC: kbuild-all(a)lists.01.org In-Reply-To: <ef37f149fba553de650312f3a24f784e137ff1be.1598643276.git.jdesfossez(a)digitalocean.com&gt; References: <ef37f149fba553de650312f3a24f784e137ff1be.1598643276.git.jdesfossez(a)digitalocean.com&gt; TO: Julien Desfossez <jdesfossez(a)digitalocean.com&gt; Hi Julien, [FYI, it's a private test report for your RFC patch.] [auto build test WARNING on tip/sched/core] [also build test WARNING on tip/x86/core kvm/linux-next linus/master asm-generic/master v5.9-rc2 next-20200828] [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] url: https://github.com/0day-ci/linux/commits/Julien-Desfossez/Core-scheduling... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 4fc472f1214ef75e5450f207e23ff13af6eecad4 :::::: branch date: 21 hours ago :::::: commit date: 21 hours ago config: i386-randconfig-m021-20200829 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com&gt; smatch warnings: kernel/sched/sched.h:2125 _double_lock_balance() warn: inconsistent returns '*rq_lockp(busiest)'. kernel/sched/sched.h:2125 _double_lock_balance() warn: inconsistent returns '*rq_lockp(busiest)'. # https://github.com/0day-ci/linux/commit/26eacbffc0e275e5bc6708de9b3c4dc9c... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Julien-Desfossez/Core-scheduling-v7/20200829-035707 git checkout 26eacbffc0e275e5bc6708de9b3c4dc9cf7102de vim +2125 kernel/sched/sched.h 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2096 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2097 #else 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2098 /* 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2099 * Unfair double_lock_balance: Optimizes throughput at the expense of 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2100 * latency by eliminating extra atomic operations when the locks are 97fb7a0a8944bd kernel/sched/sched.h Ingo Molnar 2018-03-03 2101 * already in proper order on entry. This favors lower CPU-ids and will 97fb7a0a8944bd kernel/sched/sched.h Ingo Molnar 2018-03-03 2102 * grant the double lock to lower CPUs over higher ids under contention, 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2103 * regardless of entry order into the function. 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2104 */ 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2105 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2106 __releases(this_rq->lock) 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2107 __acquires(busiest->lock) 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2108 __acquires(this_rq->lock) 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2109 { 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2110 if (rq_lockp(this_rq) == rq_lockp(busiest)) 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2111 return 0; 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2112 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2113 if (likely(raw_spin_trylock(rq_lockp(busiest)))) 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2114 return 0; 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2115 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2116 if (rq_lockp(busiest) >= rq_lockp(this_rq)) { 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2117 raw_spin_lock_nested(rq_lockp(busiest), SINGLE_DEPTH_NESTING); 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2118 return 0; 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2119 } 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2120 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2121 raw_spin_unlock(rq_lockp(this_rq)); 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2122 raw_spin_lock(rq_lockp(busiest)); 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2123 raw_spin_lock_nested(rq_lockp(this_rq), SINGLE_DEPTH_NESTING); 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 2124 26eacbffc0e275 kernel/sched/sched.h Peter Zijlstra 2020-08-28 @2125 return 1; 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2126 } 029632fbb7b7c9 kernel/sched.h Peter Zijlstra 2011-10-25 2127 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org