Hi Alex, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linus/master] [cannot apply to v5.4-rc6 next-20191108] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Alex-Kogan/locking-qspinlock-Rename-mcs-lock-unlock-macros-and-make-them-more-generic/20191109-180535 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 0058b0a506e40d9a2c62015fe92eb64a44d78cd9 reproduce: # apt-get install sparse # sparse version: v0.6.1-21-gb31adac-dirty make ARCH=x86_64 allmodconfig make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp@xxxxxxxxx> sparse warnings: (new ones prefixed by >>) kernel/locking/qspinlock.c:450:14: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *[assigned] node @@ got ct mcs_spinlock *[assigned] node @@ kernel/locking/qspinlock.c:450:14: sparse: expected struct mcs_spinlock *[assigned] node kernel/locking/qspinlock.c:450:14: sparse: got struct mcs_spinlock [pure] * kernel/locking/qspinlock.c:498:22: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *prev @@ got struct struct mcs_spinlock *prev @@ kernel/locking/qspinlock.c:498:22: sparse: expected struct mcs_spinlock *prev kernel/locking/qspinlock.c:498:22: sparse: got struct mcs_spinlock [pure] * >> kernel/locking/qspinlock_cna.h:141:60: sparse: sparse: incorrect type in initializer (different modifiers) @@ expected struct mcs_spinlock *tail_2nd @@ got struct struct mcs_spinlock *tail_2nd @@ >> kernel/locking/qspinlock_cna.h:141:60: sparse: expected struct mcs_spinlock *tail_2nd >> kernel/locking/qspinlock_cna.h:141:60: sparse: got struct mcs_spinlock [pure] * kernel/locking/qspinlock.c:450:14: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *[assigned] node @@ got ct mcs_spinlock *[assigned] node @@ kernel/locking/qspinlock.c:450:14: sparse: expected struct mcs_spinlock *[assigned] node kernel/locking/qspinlock.c:450:14: sparse: got struct mcs_spinlock [pure] * kernel/locking/qspinlock.c:498:22: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *prev @@ got struct struct mcs_spinlock *prev @@ kernel/locking/qspinlock.c:498:22: sparse: expected struct mcs_spinlock *prev kernel/locking/qspinlock.c:498:22: sparse: got struct mcs_spinlock [pure] * >> kernel/locking/qspinlock_cna.h:107:18: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *tail_2nd @@ got struct struct mcs_spinlock *tail_2nd @@ kernel/locking/qspinlock_cna.h:107:18: sparse: expected struct mcs_spinlock *tail_2nd kernel/locking/qspinlock_cna.h:107:18: sparse: got struct mcs_spinlock [pure] * >> kernel/locking/qspinlock_cna.h:240:61: sparse: sparse: incorrect type in argument 2 (different modifiers) @@ expected struct mcs_spinlock *pred_start @@ got struct struct mcs_spinlock *pred_start @@ >> kernel/locking/qspinlock_cna.h:240:61: sparse: expected struct mcs_spinlock *pred_start kernel/locking/qspinlock_cna.h:240:61: sparse: got struct mcs_spinlock [pure] * kernel/locking/qspinlock_cna.h:252:26: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *tail_2nd @@ got struct struct mcs_spinlock *tail_2nd @@ kernel/locking/qspinlock_cna.h:252:26: sparse: expected struct mcs_spinlock *tail_2nd kernel/locking/qspinlock_cna.h:252:26: sparse: got struct mcs_spinlock [pure] * kernel/locking/qspinlock.c:450:14: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *[assigned] node @@ got ct mcs_spinlock *[assigned] node @@ kernel/locking/qspinlock.c:450:14: sparse: expected struct mcs_spinlock *[assigned] node kernel/locking/qspinlock.c:450:14: sparse: got struct mcs_spinlock [pure] * kernel/locking/qspinlock.c:498:22: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *prev @@ got struct struct mcs_spinlock *prev @@ kernel/locking/qspinlock.c:498:22: sparse: expected struct mcs_spinlock *prev kernel/locking/qspinlock.c:498:22: sparse: got struct mcs_spinlock [pure] * vim +141 kernel/locking/qspinlock_cna.h 90 91 static inline bool cna_try_change_tail(struct qspinlock *lock, u32 val, 92 struct mcs_spinlock *node) 93 { 94 struct mcs_spinlock *head_2nd, *tail_2nd; 95 u32 new; 96 97 /* If the secondary queue is empty, do what MCS does. */ 98 if (node->locked <= 1) 99 return __try_clear_tail(lock, val, node); 100 101 /* 102 * Try to update the tail value to the last node in the secondary queue. 103 * If successful, pass the lock to the first thread in the secondary 104 * queue. Doing those two actions effectively moves all nodes from the 105 * secondary queue into the main one. 106 */ > 107 tail_2nd = decode_tail(node->locked); 108 head_2nd = tail_2nd->next; 109 new = ((struct cna_node *)tail_2nd)->encoded_tail + _Q_LOCKED_VAL; 110 111 if (atomic_try_cmpxchg_relaxed(&lock->val, &val, new)) { 112 /* 113 * Try to reset @next in tail_2nd to NULL, but no need to check 114 * the result - if failed, a new successor has updated it. 115 */ 116 cmpxchg_relaxed(&tail_2nd->next, head_2nd, NULL); 117 arch_mcs_pass_lock(&head_2nd->locked, 1); 118 return true; 119 } 120 121 return false; 122 } 123 124 /* 125 * cna_splice_tail -- splice nodes in the main queue between [first, last] 126 * onto the secondary queue. 127 */ 128 static void cna_splice_tail(struct mcs_spinlock *node, 129 struct mcs_spinlock *first, 130 struct mcs_spinlock *last) 131 { 132 /* remove [first,last] */ 133 node->next = last->next; 134 135 /* stick [first,last] on the secondary queue tail */ 136 if (node->locked <= 1) { /* if secondary queue is empty */ 137 /* create secondary queue */ 138 last->next = first; 139 } else { 140 /* add to the tail of the secondary queue */ > 141 struct mcs_spinlock *tail_2nd = decode_tail(node->locked); 142 struct mcs_spinlock *head_2nd = tail_2nd->next; 143 144 tail_2nd->next = first; 145 last->next = head_2nd; 146 } 147 148 node->locked = ((struct cna_node *)last)->encoded_tail; 149 } 150 151 /* 152 * cna_scan_main_queue - scan the main waiting queue looking for the first 153 * thread running on the same NUMA node as the lock holder. If found (call it 154 * thread T), move all threads in the main queue between the lock holder and 155 * T to the end of the secondary queue and return 0; otherwise, return the 156 * encoded pointer of the last scanned node in the primary queue (so a 157 * subsequent scan can be resumed from that node) 158 * 159 * Schematically, this may look like the following (nn stands for numa_node and 160 * et stands for encoded_tail). 161 * 162 * when cna_scan_main_queue() is called (the secondary queue is empty): 163 * 164 * A+------------+ B+--------+ C+--------+ T+--------+ 165 * |mcs:next | -> |mcs:next| -> |mcs:next| -> |mcs:next| -> NULL 166 * |mcs:locked=1| |cna:nn=0| |cna:nn=2| |cna:nn=1| 167 * |cna:nn=1 | +--------+ +--------+ +--------+ 168 * +----------- + 169 * 170 * when cna_scan_main_queue() returns (the secondary queue contains B and C): 171 * 172 * A+----------------+ T+--------+ 173 * |mcs:next | -> |mcs:next| -> NULL 174 * |mcs:locked=C.et | -+ |cna:nn=1| 175 * |cna:nn=1 | | +--------+ 176 * +--------------- + +-----+ 177 * \/ 178 * B+--------+ C+--------+ 179 * |mcs:next| -> |mcs:next| -+ 180 * |cna:nn=0| |cna:nn=2| | 181 * +--------+ +--------+ | 182 * ^ | 183 * +---------------------+ 184 * 185 * The worst case complexity of the scan is O(n), where n is the number 186 * of current waiters. However, the amortized complexity is close to O(1), 187 * as the immediate successor is likely to be running on the same node once 188 * threads from other nodes are moved to the secondary queue. 189 */ 190 static u32 cna_scan_main_queue(struct mcs_spinlock *node, 191 struct mcs_spinlock *pred_start) 192 { 193 struct cna_node *cn = (struct cna_node *)node; 194 struct cna_node *cni = (struct cna_node *)READ_ONCE(pred_start->next); 195 struct cna_node *last; 196 int my_numa_node = cn->numa_node; 197 198 /* find any next waiter on 'our' NUMA node */ 199 for (last = cn; 200 cni && cni->numa_node != my_numa_node; 201 last = cni, cni = (struct cna_node *)READ_ONCE(cni->mcs.next)) 202 ; 203 204 /* if found, splice any skipped waiters onto the secondary queue */ 205 if (cni) { 206 if (last != cn) /* did we skip any waiters? */ 207 cna_splice_tail(node, node->next, 208 (struct mcs_spinlock *)last); 209 return 0; 210 } 211 212 return last->encoded_tail; 213 } 214 215 __always_inline u32 cna_pre_scan(struct qspinlock *lock, 216 struct mcs_spinlock *node) 217 { 218 struct cna_node *cn = (struct cna_node *)node; 219 220 cn->pre_scan_result = cna_scan_main_queue(node, node); 221 222 return 0; 223 } 224 225 static inline void cna_pass_lock(struct mcs_spinlock *node, 226 struct mcs_spinlock *next) 227 { 228 struct cna_node *cn = (struct cna_node *)node; 229 struct mcs_spinlock *next_holder = next, *tail_2nd; 230 u32 val = 1; 231 232 u32 scan = cn->pre_scan_result; 233 234 /* 235 * check if a successor from the same numa node has not been found in 236 * pre-scan, and if so, try to find it in post-scan starting from the 237 * node where pre-scan stopped (stored in @pre_scan_result) 238 */ 239 if (scan > 0) > 240 scan = cna_scan_main_queue(node, decode_tail(scan)); --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx Intel Corporation
