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:	Mon, 10 Feb 2014 15:34:29 +0530
From:	Preeti Murthy <preeti.lkml@...il.com>
To:	Daniel Lezcano <daniel.lezcano@...aro.org>
Cc:	Peter Zijlstra <peterz@...radead.org>, mingo@...nel.org,
	alex.shi@...aro.org, LKML <linux-kernel@...r.kernel.org>,
	Lists linaro-kernel <linaro-kernel@...ts.linaro.org>,
	Preeti U Murthy <preeti@...ux.vnet.ibm.com>
Subject: Re: [PATCH V2 3/3] sched: Move idle_stamp up to the core

Hi Daniel,

On Fri, Feb 7, 2014 at 4:40 AM, Daniel Lezcano
<daniel.lezcano@...aro.org> wrote:
> The idle_balance modifies the idle_stamp field of the rq, making this
> information to be shared across core.c and fair.c. As we can know if the
> cpu is going to idle or not with the previous patch, let's encapsulate the
> idle_stamp information in core.c by moving it up to the caller. The
> idle_balance function returns true in case a balancing occured and the cpu
> won't be idle, false if no balance happened and the cpu is going idle.
>
> Cc: mingo@...nel.org
> Cc: alex.shi@...aro.org
> Cc: peterz@...radead.org
> Signed-off-by: Daniel Lezcano <daniel.lezcano@...aro.org>
> Signed-off-by: Peter Zijlstra <peterz@...radead.org>
> ---
>  kernel/sched/core.c  |   13 +++++++++++--
>  kernel/sched/fair.c  |   14 ++++++--------
>  kernel/sched/sched.h |    8 +-------
>  3 files changed, 18 insertions(+), 17 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 16b97dd..428ee4c 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -2704,8 +2704,17 @@ need_resched:
>
>         pre_schedule(rq, prev);
>
> -       if (unlikely(!rq->nr_running))
> -               idle_balance(rq);
> +#ifdef CONFIG_SMP
> +       if (unlikely(!rq->nr_running)) {
> +               /*
> +                * We must set idle_stamp _before_ calling idle_balance(), such
> +                * that we measure the duration of idle_balance() as idle time.

Should not this be "such that we *do not* measure the duration of idle_balance()
as idle time?"

Thanks

Regards
Preeti U Murthy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists