x86/itmt: Use guard() for itmt_update_mutex

Use guard() for itmt_update_mutex which avoids the extra mutex_unlock()
in the bailout and return paths.

Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Link: https://lore.kernel.org/r/20241223043407.1611-3-kprateek.nayak@amd.com

diff --git a/arch/x86/kernel/itmt.c b/arch/x86/kernel/itmt.c
index 28f449123d689b3e083466aa864e0ae503058975..ee43d1bd41d08484aea103bbb76fd77401b4e8d5 100644 (file)
--- a/arch/x86/kernel/itmt.c
+++ b/arch/x86/kernel/itmt.c
@@ -44,12 +44,10 @@ static int sched_itmt_update_handler(const struct ctl_table *table, int write,
        unsigned int old_sysctl;
        int ret;
 
-       mutex_lock(&itmt_update_mutex);
+       guard(mutex)(&itmt_update_mutex);
 
-       if (!sched_itmt_capable) {
-               mutex_unlock(&itmt_update_mutex);
+       if (!sched_itmt_capable)
                return -EINVAL;
-       }
 
        old_sysctl = sysctl_sched_itmt_enabled;
        ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
@@ -59,8 +57,6 @@ static int sched_itmt_update_handler(const struct ctl_table *table, int write,
                rebuild_sched_domains();
        }
 
-       mutex_unlock(&itmt_update_mutex);
-
        return ret;
 }
 
@@ -97,18 +93,14 @@ static struct ctl_table_header *itmt_sysctl_header;
  */
 int sched_set_itmt_support(void)
 {
-       mutex_lock(&itmt_update_mutex);
+       guard(mutex)(&itmt_update_mutex);
 
-       if (sched_itmt_capable) {
-               mutex_unlock(&itmt_update_mutex);
+       if (sched_itmt_capable)
                return 0;
-       }
 
        itmt_sysctl_header = register_sysctl("kernel", itmt_kern_table);
-       if (!itmt_sysctl_header) {
-               mutex_unlock(&itmt_update_mutex);
+       if (!itmt_sysctl_header)
                return -ENOMEM;
-       }
 
        sched_itmt_capable = true;
 
@@ -117,8 +109,6 @@ int sched_set_itmt_support(void)
        x86_topology_update = true;
        rebuild_sched_domains();
 
-       mutex_unlock(&itmt_update_mutex);
-
        return 0;
 }
 
@@ -134,12 +124,11 @@ int sched_set_itmt_support(void)
  */
 void sched_clear_itmt_support(void)
 {
-       mutex_lock(&itmt_update_mutex);
+       guard(mutex)(&itmt_update_mutex);
 
-       if (!sched_itmt_capable) {
-               mutex_unlock(&itmt_update_mutex);
+       if (!sched_itmt_capable)
                return;
-       }
+
        sched_itmt_capable = false;
 
        if (itmt_sysctl_header) {
@@ -153,8 +142,6 @@ void sched_clear_itmt_support(void)
                x86_topology_update = true;
                rebuild_sched_domains();
        }
-
-       mutex_unlock(&itmt_update_mutex);
 }
 
 int arch_asym_cpu_priority(int cpu)