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SubjectRe: [PATCH v2 1/2] time/sched_clock: Disable interrupts in sched_clock_register
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Date
On 07/01/2020 02:06, Paul Cercueil wrote:
> Instead of issueing a warning if sched_clock_register is called from a
> context where IRQs are enabled, the code now ensures that IRQs are
> indeed disabled.
>
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>


> ---
>
> Notes:
> v2: New patch
>
> kernel/time/sched_clock.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
> index dbd69052eaa6..e4332e3e2d56 100644
> --- a/kernel/time/sched_clock.c
> +++ b/kernel/time/sched_clock.c
> @@ -169,14 +169,15 @@ sched_clock_register(u64 (*read)(void), int bits, unsigned long rate)
> {
> u64 res, wrap, new_mask, new_epoch, cyc, ns;
> u32 new_mult, new_shift;
> - unsigned long r;
> + unsigned long r, flags;
> char r_unit;
> struct clock_read_data rd;
>
> if (cd.rate > rate)
> return;
>
> - WARN_ON(!irqs_disabled());
> + /* Cannot register a sched_clock with interrupts on */
> + local_irq_save(flags);
>
> /* Calculate the mult/shift to convert counter ticks to ns. */
> clocks_calc_mult_shift(&new_mult, &new_shift, rate, NSEC_PER_SEC, 3600);
> @@ -233,6 +234,8 @@ sched_clock_register(u64 (*read)(void), int bits, unsigned long rate)
> if (irqtime > 0 || (irqtime == -1 && rate >= 1000000))
> enable_sched_clock_irqtime();
>
> + local_irq_restore(flags);
> +
> pr_debug("Registered %pS as sched_clock source\n", read);
> }
>
>


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