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From: Paul Cercueil <paul@crapouillou.net>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: od@zcrc.me, linux-kernel@vger.kernel.org,
	Paul Cercueil <paul@crapouillou.net>
Subject: [PATCH v2 1/2] time/sched_clock: Disable interrupts in sched_clock_register
Date: Tue,  7 Jan 2020 02:06:29 +0100
Message-ID: <20200107010630.954648-1-paul@crapouillou.net> (raw)

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


             reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-07  1:06 Paul Cercueil [this message]
2020-01-07  1:06 ` [PATCH v2 2/2] clocksource: Add driver for the Ingenic JZ47xx OST Paul Cercueil
2020-01-09 14:28   ` Thomas Gleixner
2020-01-09 18:26     ` Paul Cercueil
2020-01-09 11:55 ` [PATCH v2 1/2] time/sched_clock: Disable interrupts in sched_clock_register Daniel Lezcano
2020-01-09 17:33 ` [tip: timers/core] time/sched_clock: Disable interrupts in sched_clock_register() tip-bot2 for Paul Cercueil
2020-01-09 17:56 ` tip-bot2 for Paul Cercueil

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