[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20071023165119.5536.8213.stgit@novell1.haskins.net>
Date: Tue, 23 Oct 2007 12:51:19 -0400
From: Gregory Haskins <ghaskins@...ell.com>
To: linux-rt-users@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
Gregory Haskins <ghaskins@...ell.com>,
Steven Rostedt <rostedt@...dmis.org>,
Dmitry Adamushko <dmitry.adamushko@...il.com>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Ingo Molnar <mingo@...e.hu>, Darren Hart <dvhltc@...ibm.com>
Subject: [PATCH 11/13] RT: Condense NORMAL and IDLE priorities
We only need to track if the CPU is in a non-RT state, as opposed to its
priority within the non-RT state. So simplify setting in the effort of
reducing cache-thrash.
Signed-off-by: Gregory Haskins <ghaskins@...ell.com>
---
kernel/sched.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index a1f1d92..4abe738 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -371,11 +371,19 @@ static inline void set_rq_prio(struct rq *rq, int prio)
rq->highest_prio = prio;
}
+/*
+ * We dont care what the exact normal priority is. We only care about
+ * RT-priority, vs non-RT (normal or idle). So flatten the priority if its a
+ * non-RT variety. This will reduce cache-thrashing on the rq->highest_prio.
+ */
static inline void update_rq_prio(struct rq *rq)
{
struct rt_prio_array *array = &rq->rt.active;
int prio = sched_find_first_bit(array->bitmap);
+ if ((prio != MAX_PRIO) && (prio > MAX_RT_PRIO))
+ prio = MAX_RT_PRIO;
+
if (rq->highest_prio != prio)
set_rq_prio(rq, prio);
}
-
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