tree: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git mpam/snapshot/v5.15 head: ce3629841262f725a5f3a327403fcaf0e604a85e commit: 016782894eb4694b95d6b67f4b1794cde795482c [62/139] x86/resctrl: Move the restrl code to fs config: x86_64-randconfig-m001-20211115 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; New smatch warnings: fs/resctrl/monitor.c:102 __check_limbo() warn: unsigned 'arch_mon_ctx' is never less than zero. fs/resctrl/monitor.c:238 add_rmid_to_limbo() warn: unsigned 'arch_mon_ctx' is never less than zero. fs/resctrl/monitor.c:369 mon_event_count() warn: unsigned 'rr->arch_mon_ctx' is never less than zero. fs/resctrl/monitor.c:537 mbm_update() warn: unsigned 'rr.arch_mon_ctx' is never less than zero. fs/resctrl/rdtgroup.c:3011 rdtgroup_mkdir_ctrl_mon() error: uninitialized symbol 'rmid'. Old smatch warnings: fs/resctrl/monitor.c:547 mbm_update() warn: unsigned 'rr.arch_mon_ctx' is never less than zero. vim +/arch_mon_ctx +102 fs/resctrl/monitor.c 84 85 /* 86 * Check the RMIDs that are marked as busy for this domain. If the 87 * reported LLC occupancy is below the threshold clear the busy bit and 88 * decrement the count. If the busy count gets to zero on an RMID, we 89 * free the RMID 90 */ 91 void __check_limbo(struct rdt_domain *d, bool force_free) 92 { 93 struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); 94 u32 idx_limit = resctrl_arch_system_num_rmid_idx(); 95 unsigned long arch_mon_ctx; 96 struct rmid_entry *entry; 97 u32 idx, cur_idx = 1; 98 bool rmid_dirty; 99 u64 val = 0; 100 101 arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID); 103 return; 104 105 /* 106 * Skip RMID 0 and start from RMID 1 and check all the RMIDs that 107 * are marked as busy for occupancy < threshold. If the occupancy 108 * is less than the threshold decrement the busy counter of the 109 * RMID and move it to the free list when the counter reaches 0. 110 */ 111 for (;;) { 112 idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx); 113 if (idx >= idx_limit) 114 break; 115 116 entry = __rmid_entry(idx); 117 if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid, 118 QOS_L3_OCCUP_EVENT_ID, &val, 119 arch_mon_ctx)) { 120 rmid_dirty = true; 121 } else { 122 rmid_dirty = (val >= resctrl_rmid_realloc_threshold); 123 } 124 125 if (force_free || !rmid_dirty) { 126 clear_bit(idx, d->rmid_busy_llc); 127 if (!--entry->busy) { 128 rmid_limbo_count--; 129 list_add_tail(&entry->list, &rmid_free_lru); 130 } 131 } 132 cur_idx = idx + 1; 133 } 134 135 resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx); 136 } 137 138 bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d) 139 { 140 u32 idx_limit = resctrl_arch_system_num_rmid_idx(); 141 142 return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit; 143 } 144 145 static struct rmid_entry *resctrl_find_free_rmid(u32 closid) 146 { 147 struct rmid_entry *itr; 148 u32 itr_idx, cmp_idx; 149 150 if (list_empty(&rmid_free_lru)) 151 return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC); 152 153 list_for_each_entry(itr, &rmid_free_lru, list) { 154 /* 155 * get the index of this free rmid, and the index it would need 156 * to be if it were used with this closid. 157 * If the closid is irrelevant on this architecture, these will 158 * always be the same. Otherwise they will only match if this 159 * rmid can be used with this closid. 160 */ 161 itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid); 162 cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid); 163 164 if (itr_idx == cmp_idx) 165 return itr; 166 } 167 168 return ERR_PTR(-ENOSPC); 169 } 170 171 /** 172 * resctrl_closid_is_dirty - Determine if clean rmid can be allocate for this 173 * closid. 174 * @closid: The closid that is being queried. 175 * 176 * MPAM's equivalent of rmid are per-closid, meaning a freshly allocate closid 177 * may not be able to allocate clean rmid. To avoid this the allocator will 178 * only return clean closid. 179 */ 180 bool resctrl_closid_is_dirty(u32 closid) 181 { 182 struct rmid_entry *entry; 183 int i; 184 185 lockdep_assert_held(&rdtgroup_mutex); 186 187 if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) 188 return false; 189 190 for (i = 0; i < resctrl_arch_system_num_rmid_idx(); i++) { 191 entry = &rmid_ptrs[i]; 192 if (entry->closid != closid) 193 continue; 194 195 if (entry->busy) 196 return true; 197 } 198 199 return false; 200 } 201 202 /* 203 * As of now the RMIDs allocation is the same in each domain. 204 * However we keep track of which packages the RMIDs 205 * are used to optimize the limbo list management. 206 * The closid is ignored on x86. 207 */ 208 int alloc_rmid(u32 closid) 209 { 210 struct rmid_entry *entry; 211 212 lockdep_assert_held(&rdtgroup_mutex); 213 214 entry = resctrl_find_free_rmid(closid); 215 if (!IS_ERR(entry)) { 216 list_del(&entry->list); 217 return entry->rmid; 218 } 219 220 return PTR_ERR(entry); 221 } 222 223 static void add_rmid_to_limbo(struct rmid_entry *entry) 224 { 225 struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); 226 unsigned long arch_mon_ctx; 227 struct rdt_domain *d; 228 u64 val = 0; 229 u32 idx; 230 int err; 231 232 /* Walking r->domains, ensure it can't race with cpuhp */ 233 lockdep_assert_cpus_held(); 234 235 idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid); 236 237 arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID); 239 return; 240 241 entry->busy = 0; 242 list_for_each_entry(d, &r->domains, list) { 243 err = resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid, 244 QOS_L3_OCCUP_EVENT_ID, &val, 245 arch_mon_ctx); 246 if (err || val <= resctrl_rmid_realloc_threshold) 247 continue; 248 249 /* 250 * For the first limbo RMID in the domain, 251 * setup up the limbo worker. 252 */ 253 if (!has_busy_rmid(r, d)) 254 cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL, -1); 255 set_bit(idx, d->rmid_busy_llc); 256 entry->busy++; 257 } 258 resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx); 259 260 if (entry->busy) 261 rmid_limbo_count++; 262 else 263 list_add_tail(&entry->list, &rmid_free_lru); 264 } 265 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org