linux-kernel - Re: [PATCH v2 13/13] cpuidle: Use local_clock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 19 May 2023 16:13:41 +0200
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     bigeasy@...utronix.de, mark.rutland@....com, maz@...nel.org,
        catalin.marinas@....com, will@...nel.org, chenhuacai@...nel.org,
        kernel@...0n.name, hca@...ux.ibm.com, gor@...ux.ibm.com,
        agordeev@...ux.ibm.com, borntraeger@...ux.ibm.com,
        svens@...ux.ibm.com, pbonzini@...hat.com, wanpengli@...cent.com,
        vkuznets@...hat.com, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, dave.hansen@...ux.intel.com, x86@...nel.org,
        hpa@...or.com, jgross@...e.com, boris.ostrovsky@...cle.com,
        daniel.lezcano@...aro.org, kys@...rosoft.com,
        haiyangz@...rosoft.com, wei.liu@...nel.org, decui@...rosoft.com,
        rafael@...nel.org, longman@...hat.com, boqun.feng@...il.com,
        pmladek@...e.com, senozhatsky@...omium.org, rostedt@...dmis.org,
        john.ogness@...utronix.de, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, dietmar.eggemann@....com,
        bsegall@...gle.com, mgorman@...e.de, bristot@...hat.com,
        vschneid@...hat.com, jstultz@...gle.com, sboyd@...nel.org,
        linux-kernel@...r.kernel.org, loongarch@...ts.linux.dev,
        linux-s390@...r.kernel.org, kvm@...r.kernel.org,
        linux-hyperv@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [PATCH v2 13/13] cpuidle: Use local_clock_noinstr()

On Fri, May 19, 2023 at 12:33 PM Peter Zijlstra <peterz@...radead.org> wrote:
>
> With the introduction of local_clock_noinstr(), local_clock() itself
> is no longer marked noinstr, use the correct function.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>

Acked-by: Rafael J. Wysocki <rafael@...nel.org>

> ---
>  drivers/cpuidle/cpuidle.c    |    8 ++++----
>  drivers/cpuidle/poll_state.c |    4 ++--
>  2 files changed, 6 insertions(+), 6 deletions(-)
>
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -145,7 +145,7 @@ static noinstr void enter_s2idle_proper(
>
>         instrumentation_begin();
>
> -       time_start = ns_to_ktime(local_clock());
> +       time_start = ns_to_ktime(local_clock_noinstr());
>
>         tick_freeze();
>         /*
> @@ -169,7 +169,7 @@ static noinstr void enter_s2idle_proper(
>         tick_unfreeze();
>         start_critical_timings();
>
> -       time_end = ns_to_ktime(local_clock());
> +       time_end = ns_to_ktime(local_clock_noinstr());
>
>         dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start);
>         dev->states_usage[index].s2idle_usage++;
> @@ -243,7 +243,7 @@ noinstr int cpuidle_enter_state(struct c
>         sched_idle_set_state(target_state);
>
>         trace_cpu_idle(index, dev->cpu);
> -       time_start = ns_to_ktime(local_clock());
> +       time_start = ns_to_ktime(local_clock_noinstr());
>
>         stop_critical_timings();
>         if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {
> @@ -276,7 +276,7 @@ noinstr int cpuidle_enter_state(struct c
>         start_critical_timings();
>
>         sched_clock_idle_wakeup_event();
> -       time_end = ns_to_ktime(local_clock());
> +       time_end = ns_to_ktime(local_clock_noinstr());
>         trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
>
>         /* The cpu is no longer idle or about to enter idle. */
> --- a/drivers/cpuidle/poll_state.c
> +++ b/drivers/cpuidle/poll_state.c
> @@ -15,7 +15,7 @@ static int __cpuidle poll_idle(struct cp
>  {
>         u64 time_start;
>
> -       time_start = local_clock();
> +       time_start = local_clock_noinstr();
>
>         dev->poll_time_limit = false;
>
> @@ -32,7 +32,7 @@ static int __cpuidle poll_idle(struct cp
>                                 continue;
>
>                         loop_count = 0;
> -                       if (local_clock() - time_start > limit) {
> +                       if (local_clock_noinstr() - time_start > limit) {
>                                 dev->poll_time_limit = true;
>                                 break;
>                         }
>
>