Hi Daniel, On 02/11/2014 05:37 PM, Daniel Lezcano wrote: > On 02/10/2014 11:04 AM, Preeti Murthy wrote: >> Hi Daniel, >> >> On Fri, Feb 7, 2014 at 4:40 AM, Daniel Lezcano >> <[email protected]> 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: [email protected] >>> Cc: [email protected] >>> Cc: [email protected] >>> Signed-off-by: Daniel Lezcano <[email protected]> >>> Signed-off-by: Peter Zijlstra <[email protected]> >>> --- >>> 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.
Oh sorry! Yes you are right. Thanks Regards Preeti U Murthy > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
