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Subject[PATCH v2 1/2] time/sched_clock: Disable interrupts in sched_clock_register
Date
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>
---

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);
}

--
2.24.1
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