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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
rcu/nocb: Consolidate rcu_nocb_cpu_offload/deoffload functions
The rcu_nocb_cpu_offload() and rcu_nocb_cpu_deoffload() functions are
nearly duplicates.
Therefore, extract the common logic into rcu_nocb_cpu_toggle_offload()
which takes an 'offload' boolean, and make both exported functions
simple wrappers.
This eliminates a bunch of duplicate code at the call sites, namely
mutex locking, CPU hotplug locking and CPU online checks.
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
+35
-35
+35
-35
kernel/rcu/tree_nocb.h
+35
-35
kernel/rcu/tree_nocb.h
···
1081
1081
return 0;
1082
1082
}
1083
1083
1084
-
int rcu_nocb_cpu_deoffload(int cpu)
1085
-
{
1086
-
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
1087
-
int ret = 0;
1088
-
1089
-
cpus_read_lock();
1090
-
mutex_lock(&rcu_state.nocb_mutex);
1091
-
if (rcu_rdp_is_offloaded(rdp)) {
1092
-
if (!cpu_online(cpu)) {
1093
-
ret = rcu_nocb_rdp_deoffload(rdp);
1094
-
if (!ret)
1095
-
cpumask_clear_cpu(cpu, rcu_nocb_mask);
1096
-
} else {
1097
-
pr_info("NOCB: Cannot CB-deoffload online CPU %d\n", rdp->cpu);
1098
-
ret = -EINVAL;
1099
-
}
1100
-
}
1101
-
mutex_unlock(&rcu_state.nocb_mutex);
1102
-
cpus_read_unlock();
1103
-
1104
-
return ret;
1105
-
}
1106
-
EXPORT_SYMBOL_GPL(rcu_nocb_cpu_deoffload);
1107
-
1108
1084
static bool rcu_nocb_rdp_offload_wait_cond(struct rcu_data *rdp)
1109
1085
{
1110
1086
unsigned long flags;
···
1125
1149
return 0;
1126
1150
}
1127
1151
1128
-
int rcu_nocb_cpu_offload(int cpu)
1152
+
/* Common helper for CPU offload/deoffload operations. */
1153
+
static int rcu_nocb_cpu_toggle_offload(int cpu, bool offload)
1129
1154
{
1130
1155
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
1131
1156
int ret = 0;
1132
1157
1133
1158
cpus_read_lock();
1134
1159
mutex_lock(&rcu_state.nocb_mutex);
1135
-
if (!rcu_rdp_is_offloaded(rdp)) {
1136
-
if (!cpu_online(cpu)) {
1137
-
ret = rcu_nocb_rdp_offload(rdp);
1138
-
if (!ret)
1139
-
cpumask_set_cpu(cpu, rcu_nocb_mask);
1140
-
} else {
1141
-
pr_info("NOCB: Cannot CB-offload online CPU %d\n", rdp->cpu);
1142
-
ret = -EINVAL;
1143
-
}
1160
+
1161
+
/* Already in desired state, nothing to do. */
1162
+
if (rcu_rdp_is_offloaded(rdp) == offload)
1163
+
goto out_unlock;
1164
+
1165
+
if (cpu_online(cpu)) {
1166
+
pr_info("NOCB: Cannot CB-%soffload online CPU %d\n",
1167
+
offload ? "" : "de", rdp->cpu);
1168
+
ret = -EINVAL;
1169
+
goto out_unlock;
1144
1170
}
1171
+
1172
+
if (offload) {
1173
+
ret = rcu_nocb_rdp_offload(rdp);
1174
+
if (!ret)
1175
+
cpumask_set_cpu(cpu, rcu_nocb_mask);
1176
+
} else {
1177
+
ret = rcu_nocb_rdp_deoffload(rdp);
1178
+
if (!ret)
1179
+
cpumask_clear_cpu(cpu, rcu_nocb_mask);
1180
+
}
1181
+
1182
+
out_unlock:
1145
1183
mutex_unlock(&rcu_state.nocb_mutex);
1146
1184
cpus_read_unlock();
1147
-
1148
1185
return ret;
1186
+
}
1187
+
1188
+
int rcu_nocb_cpu_deoffload(int cpu)
1189
+
{
1190
+
return rcu_nocb_cpu_toggle_offload(cpu, false /* de-offload */);
1191
+
}
1192
+
EXPORT_SYMBOL_GPL(rcu_nocb_cpu_deoffload);
1193
+
1194
+
int rcu_nocb_cpu_offload(int cpu)
1195
+
{
1196
+
return rcu_nocb_cpu_toggle_offload(cpu, true /* offload */);
1149
1197
}
1150
1198
EXPORT_SYMBOL_GPL(rcu_nocb_cpu_offload);
1151
1199