On Wed, 2024-12-11 at 18:55 +0000, K Prateek Nayak wrote:
> Use guard() for itmt_update_mutex which avoids the extra mutex_unlock()
> in the bailout and return paths.
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Tim
>
> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
> ---
> arch/x86/kernel/itmt.c | 29 ++++++++---------------------
> 1 file changed, 8 insertions(+), 21 deletions(-)
>
> diff --git a/arch/x86/kernel/itmt.c b/arch/x86/kernel/itmt.c
> index 28f449123d68..ee43d1bd41d0 100644
> --- 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)