Linux-RISC-V Archive on lore.kernel.org
 help / color / Atom feed
From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Anup Patel <anup@brainfault.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Palmer Dabbelt <palmer@sifive.com>,
	Albert Ou <aou@eecs.berkeley.edu>
Cc: Christoph Hellwig <hch@infradead.org>,
	Atish Patra <atish.patra@wdc.com>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] clocksource: riscv_timer: Provide sched_clock
Date: Mon, 3 Dec 2018 13:59:09 +0100
Message-ID: <c970d873-9dbc-9f21-3380-89635d6f574a@linaro.org> (raw)
In-Reply-To: <20181203123524.11778-1-anup@brainfault.org>

On 03/12/2018 13:35, Anup Patel wrote:
> Currently, we don't have a sched_clock registered for RISC-V systems.
> This means Linux time keeping will use jiffies (running at HZ) as the
> default sched_clock.
> 
> To avoid this, we explicity provide sched_clock using RISC-V rdtime
> instruction (similar to riscv_timer clocksource).
> 
> Signed-off-by: Anup Patel <anup@brainfault.org>

Hi Anup,

the GENERIC_SCHED_CLOCK dependency in the Kconfig is missing.

Thanks

> ---
>  drivers/clocksource/riscv_timer.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/clocksource/riscv_timer.c b/drivers/clocksource/riscv_timer.c
> index 084e97dc10ed..431892200a08 100644
> --- a/drivers/clocksource/riscv_timer.c
> +++ b/drivers/clocksource/riscv_timer.c
> @@ -8,6 +8,7 @@
>  #include <linux/cpu.h>
>  #include <linux/delay.h>
>  #include <linux/irq.h>
> +#include <linux/sched_clock.h>
>  #include <asm/smp.h>
>  #include <asm/sbi.h>
>  
> @@ -49,6 +50,11 @@ static unsigned long long riscv_clocksource_rdtime(struct clocksource *cs)
>  	return get_cycles64();
>  }
>  
> +static u64 riscv_sched_clock(void)
> +{
> +	return get_cycles64();
> +}
> +
>  static DEFINE_PER_CPU(struct clocksource, riscv_clocksource) = {
>  	.name		= "riscv_clocksource",
>  	.rating		= 300,
> @@ -97,6 +103,9 @@ static int __init riscv_timer_init_dt(struct device_node *n)
>  	cs = per_cpu_ptr(&riscv_clocksource, cpuid);
>  	clocksource_register_hz(cs, riscv_timebase);
>  
> +	sched_clock_register(riscv_sched_clock,
> +			BITS_PER_LONG, riscv_timebase);
> +
>  	error = cpuhp_setup_state(CPUHP_AP_RISCV_TIMER_STARTING,
>  			 "clockevents/riscv/timer:starting",
>  			 riscv_timer_starting_cpu, riscv_timer_dying_cpu);
> 


-- 
 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-03 12:35 Anup Patel
2018-12-03 12:59 ` Daniel Lezcano [this message]
2018-12-03 14:50   ` Anup Patel
2018-12-03 14:53     ` Daniel Lezcano
2018-12-06 20:32 ` Palmer Dabbelt
2018-12-07  2:27   ` Anup Patel

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=c970d873-9dbc-9f21-3380-89635d6f574a@linaro.org \
    --to=daniel.lezcano@linaro.org \
    --cc=anup@brainfault.org \
    --cc=aou@eecs.berkeley.edu \
    --cc=atish.patra@wdc.com \
    --cc=hch@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=palmer@sifive.com \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-RISC-V Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-riscv/0 linux-riscv/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-riscv linux-riscv/ https://lore.kernel.org/linux-riscv \
		linux-riscv@lists.infradead.org infradead-linux-riscv@archiver.kernel.org
	public-inbox-index linux-riscv


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-riscv


AGPL code for this site: git clone https://public-inbox.org/ public-inbox