Messages in this thread |  | | Date | Tue, 11 Feb 2014 13:07:12 +0100 | From | Daniel Lezcano <> | Subject | Re: [PATCH V2 3/3] sched: Move idle_stamp up to the core |
| |
On 02/10/2014 11:04 AM, Preeti Murthy wrote: > Hi Daniel, > > On Fri, Feb 7, 2014 at 4:40 AM, Daniel Lezcano > <daniel.lezcano@linaro.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@kernel.org >> Cc: alex.shi@linaro.org >> Cc: peterz@infradead.org >> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> >> Signed-off-by: Peter Zijlstra <peterz@infradead.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?"
Actually, the initial code was including the idle balance time processing in the idle stamp. When I moved the idle stamp in core.c, idle balance was no longer measured (an unwanted change). That has been fixed and to prevent that to occur again, we added a comment.
-- <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
-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |