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-rw-r--r--kernel/rcutree.c27
1 files changed, 3 insertions, 24 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index b4efb9e36680..3df04381ea3e 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -178,29 +178,9 @@ static struct rcu_node *rcu_get_root(struct rcu_state *rsp)
178 return &rsp->node[0]; 178 return &rsp->node[0];
179} 179}
180 180
181/*
182 * Record the specified "completed" value, which is later used to validate
183 * dynticks counter manipulations and CPU-offline checks. Specify
184 * "rsp->completed - 1" to unconditionally invalidate any future dynticks
185 * manipulations and CPU-offline checks. Such invalidation is useful at
186 * the beginning of a grace period.
187 */
188static void dyntick_record_completed(struct rcu_state *rsp, long comp)
189{
190 rsp->completed_fqs = comp;
191}
192
193#ifdef CONFIG_SMP 181#ifdef CONFIG_SMP
194 182
195/* 183/*
196 * Recall the previously recorded value of the completion for dynticks.
197 */
198static long dyntick_recall_completed(struct rcu_state *rsp)
199{
200 return rsp->completed_fqs;
201}
202
203/*
204 * If the specified CPU is offline, tell the caller that it is in 184 * If the specified CPU is offline, tell the caller that it is in
205 * a quiescent state. Otherwise, whack it with a reschedule IPI. 185 * a quiescent state. Otherwise, whack it with a reschedule IPI.
206 * Grace periods can end up waiting on an offline CPU when that 186 * Grace periods can end up waiting on an offline CPU when that
@@ -702,7 +682,6 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
702 rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */ 682 rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */
703 rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS; 683 rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
704 record_gp_stall_check_time(rsp); 684 record_gp_stall_check_time(rsp);
705 dyntick_record_completed(rsp, rsp->completed - 1);
706 685
707 /* Special-case the common single-level case. */ 686 /* Special-case the common single-level case. */
708 if (NUM_RCU_NODES == 1) { 687 if (NUM_RCU_NODES == 1) {
@@ -1214,7 +1193,7 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
1214 goto unlock_ret; /* no emergency and done recently. */ 1193 goto unlock_ret; /* no emergency and done recently. */
1215 rsp->n_force_qs++; 1194 rsp->n_force_qs++;
1216 spin_lock(&rnp->lock); 1195 spin_lock(&rnp->lock);
1217 lastcomp = rsp->completed; 1196 lastcomp = rsp->gpnum - 1;
1218 signaled = rsp->signaled; 1197 signaled = rsp->signaled;
1219 rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS; 1198 rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
1220 if (lastcomp == rsp->gpnum) { 1199 if (lastcomp == rsp->gpnum) {
@@ -1248,7 +1227,7 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
1248 if (lastcomp == rsp->completed && 1227 if (lastcomp == rsp->completed &&
1249 rsp->signaled == signaled) { 1228 rsp->signaled == signaled) {
1250 rsp->signaled = RCU_FORCE_QS; 1229 rsp->signaled = RCU_FORCE_QS;
1251 dyntick_record_completed(rsp, lastcomp); 1230 rsp->completed_fqs = lastcomp;
1252 forcenow = signaled == RCU_SAVE_COMPLETED; 1231 forcenow = signaled == RCU_SAVE_COMPLETED;
1253 } 1232 }
1254 spin_unlock(&rnp->lock); 1233 spin_unlock(&rnp->lock);
@@ -1259,7 +1238,7 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
1259 case RCU_FORCE_QS: 1238 case RCU_FORCE_QS:
1260 1239
1261 /* Check dyntick-idle state, send IPI to laggarts. */ 1240 /* Check dyntick-idle state, send IPI to laggarts. */
1262 if (rcu_process_dyntick(rsp, dyntick_recall_completed(rsp), 1241 if (rcu_process_dyntick(rsp, rsp->completed_fqs,
1263 rcu_implicit_dynticks_qs)) 1242 rcu_implicit_dynticks_qs))
1264 goto unlock_ret; 1243 goto unlock_ret;
1265 1244