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From: Gautham R Shenoy <ego@in.ibm.com>
To: Ingo Molnar <mingo@elte.hu>, npiggin@suse.de
Cc: linux-kernel@vger.kernel.org, Srivatsa Vaddagiri <vatsa@in.ibm.com>
Subject: [PATCH] sched: Improve readability in update_cpu_load() code
Date: Thu, 15 May 2008 18:34:59 +0530	[thread overview]
Message-ID: <20080515130459.GA9650@in.ibm.com> (raw)

Author: Gautham R Shenoy <ego@in.ibm.com>
Date:   Thu May 15 17:55:49 2008 +0530

    sched: Improve readability in update_cpu_load() code
    
    Currently the cpu_load[i] is calculated as:
    	this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i;
    
    However, since scale = 2^i, this can be simplified as:
    	this_rq->cpu_load[i] = old_load + ((new_load - old_load) >> i);
    
    Makes it easier to read.
    Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>

diff --git a/kernel/sched.c b/kernel/sched.c
index 2d7d8f1..e1a6985 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2921,7 +2921,7 @@ static void update_cpu_load(struct rq *this_rq)
 		 */
 		if (new_load > old_load)
 			new_load += scale-1;
-		this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i;
+		this_rq->cpu_load[i] = old_load + ((new_load - old_load) >> i);
 	}
 }
 
-- 
Thanks and Regards
gautham

             reply	other threads:[~2008-05-15 13:03 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-05-15 13:04 Gautham R Shenoy [this message]
2008-05-15 14:52 ` [PATCH] sched: Improve readability in update_cpu_load() code Srivatsa Vaddagiri
2008-05-15 15:02   ` Srivatsa Vaddagiri
2008-05-15 15:15   ` Dmitry Adamushko
2008-05-15 15:31     ` Dmitry Adamushko
2008-05-15 17:11   ` Gautham R Shenoy

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