diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 2eac2adff11bcc011bab358412a5ca6067849d08..532e261b2cab7f8a5b9cf0b97640f0d36b67900b 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1526,6 +1526,15 @@ static void intel_pstate_update_util(struct update_util_data *data, u64 time,
 
 	if (flags & SCHED_CPUFREQ_IOWAIT) {
 		cpu->iowait_boost = int_tofp(1);
+		cpu->last_update = time;
+		/*
+		 * The last time the busy was 100% so P-state was max anyway
+		 * so avoid overhead of computation.
+		 */
+		if (fp_toint(cpu->sample.busy_scaled) == 100)
+			return;
+
+		goto set_pstate;
 	} else if (cpu->iowait_boost) {
 		/* Clear iowait_boost if the CPU may have been idle. */
 		delta_ns = time - cpu->last_update;
@@ -1537,6 +1546,7 @@ static void intel_pstate_update_util(struct update_util_data *data, u64 time,
 	if ((s64)delta_ns < INTEL_PSTATE_DEFAULT_SAMPLING_INTERVAL)
 		return;
 
+set_pstate:
 	if (intel_pstate_sample(cpu, time)) {
 		int target_pstate;