From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de,
peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com,
edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com,
oleg@redhat.com, sbw@mit.edu
Subject: [PATCH tip/core/rcu 0/3] Crude timer-wheel latency hacks
Date: Mon, 13 Jan 2014 20:14:50 -0800 [thread overview]
Message-ID: <20140114041449.GA13934@linux.vnet.ibm.com> (raw)
Hello!
The following three patches provide some crude timer-wheel latency
patches. I understand that a more comprehensive solution is in progress,
but in the meantime, these patches work well in cases where a given
CPU has either zero or one timers pending, which is a common case for
NO_HZ_FULL kernels. So, on the off-chance that this is helpful to
someone, the individual patches are as follows:
1. Avoid jiffy-at-a-time stepping when the timer wheel is empty.
2. Avoid jiffy-at-a-time stepping when the timer wheel transitions
to empty.
3. Avoid jiffy-at-a-time stepping after a timer is added to an
initially empty timer wheel.
Thanx, Paul
------------------------------------------------------------------------
b/kernel/timer.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
next reply other threads:[~2014-01-14 4:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-14 4:14 Paul E. McKenney [this message]
2014-01-14 4:15 ` [PATCH tip/core/timers 1/3] timers: Reduce __run_timers() latency for empty list Paul E. McKenney
2014-01-14 4:15 ` [PATCH tip/core/timers 2/3] timers: Reduce future __run_timers() latency for newly emptied list Paul E. McKenney
2014-01-14 4:15 ` [PATCH tip/core/timers 3/3] timers: Reduce future __run_timers() latency for first add to empty list Paul E. McKenney
2014-01-14 18:48 ` [PATCH tip/core/timers 1/3] timers: Reduce __run_timers() latency for " Oleg Nesterov
2014-01-14 23:50 ` Paul E. McKenney
2014-01-15 16:25 ` Oleg Nesterov
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