Messages in this thread Patch in this message | | | Date | Sun, 22 Jun 2008 14:02:55 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH -tip-rcu] Make rcutorture more vicious: make quiescent rcutorture less power-hungry |
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On Sun, Jun 22, 2008 at 01:17:12PM -0700, Arjan van de Ven wrote: > On Sun, 22 Jun 2008 13:06:38 -0700 > "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote: > > > This patch makes the non-module rcutorture a bit more friendly to > > the power-conservation code. This is a rather simple-minded approach. > > More sophisticated approaches would get rid of the rcutorture tasks > > while rcutorture execution was suppressed, but attempts thus far to > > do this have not gone well -- calling rcu_torture_init() from a /proc > > callout results in oopses. > > > > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > > --- > > > > rcutorture.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff -urpNa -X dontdiff > > linux-2.6.26-rc4-rcut2-proc/kernel/rcutorture.c > > linux-2.6.26-rc4-rcut3-procq/kernel/rcutorture.c --- > > linux-2.6.26-rc4-rcut2-proc/kernel/rcutorture.c 2008-06-22 > > 10:29:04.000000000 -0700 +++ > > linux-2.6.26-rc4-rcut3-procq/kernel/rcutorture.c 2008-06-22 > > 12:20:10.000000000 -0700 @@ -196,7 +196,10 @@ static void > > rcu_stutter_wait(void) { while (stutter_pause_test > > || !rcutorture_runnable) > > - schedule_timeout_interruptible(1); > > + if (rcutorture_runnable) > > + schedule_timeout_interruptible(1); > > + else > > + schedule_timeout_interruptible(HZ); > > } > > could you also make it use round_jiffies_relative() to make the power > impact even less..... > (by coalescing various "once a second" timers like this)
Good point!!! As follows, on top of the previous one.
This patch aligns the rcutorture wakeup times to align with all other multiple-of-a-second wakeups to further decrease power consumption.
Suggested-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> ---
rcutorture.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff -urpNa -X dontdiff linux-2.6.26-rc4-rcut3-procq/kernel/rcutorture.c linux-2.6.26-rc4-rcut4-procqp/kernel/rcutorture.c --- linux-2.6.26-rc4-rcut3-procq/kernel/rcutorture.c 2008-06-22 12:20:10.000000000 -0700 +++ linux-2.6.26-rc4-rcut4-procqp/kernel/rcutorture.c 2008-06-22 13:53:22.000000000 -0700 @@ -1,3 +1,4 @@ + /* * Read-Copy Update module-based torture test facility * @@ -199,7 +200,7 @@ rcu_stutter_wait(void) if (rcutorture_runnable) schedule_timeout_interruptible(1); else - schedule_timeout_interruptible(HZ); + schedule_timeout_interruptible(round_jiffies_relative(HZ)); } /*
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