From: Josh Triplett <josh@joshtriplett.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu,
laijs@cn.fujitsu.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca,
niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, Valdis.Kletnieks@vt.edu,
dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com,
patches@linaro.org, "Paul E. McKenney" <paul.mckenney@linaro.org>
Subject: Re: [PATCH tip/core/rcu 36/55] rcu: Prevent early boot set_need_resched() from __rcu_pending()
Date: Sun, 16 Oct 2011 18:49:15 -0700 [thread overview]
Message-ID: <20111017014915.GE19421@leaf> (raw)
In-Reply-To: <1315332049-2604-36-git-send-email-paulmck@linux.vnet.ibm.com>
On Tue, Sep 06, 2011 at 11:00:30AM -0700, Paul E. McKenney wrote:
> From: Paul E. McKenney <paul.mckenney@linaro.org>
>
> There isn't a whole lot of point in poking the scheduler before there
> are other tasks to switch to. This commit therefore adds a check
> for rcu_scheduler_fully_active in __rcu_pending() to suppress any
> pre-scheduler calls to set_need_resched(). The downside of this approach
> is additional runtime overhead in a reasonably hot code path.
If you're concerned about the runtime overhead, this does seem like a
perfect candidate for jump labels.
- Josh Triplett
next prev parent reply other threads:[~2011-10-17 1:49 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-06 18:00 [PATCH tip/core/rcu 0/55] Preview of RCU changes for 3.2 Paul E. McKenney
2011-09-06 17:59 ` [PATCH tip/core/rcu 01/55] rcu: Use kthread_create_on_node() Paul E. McKenney
2011-09-06 17:59 ` [PATCH tip/core/rcu 02/55] rcu: Avoid unnecessary self-wakeup of per-CPU kthreads Paul E. McKenney
2011-09-06 17:59 ` [PATCH tip/core/rcu 03/55] rcu: Update documentation to flag RCU_BOOST trace information Paul E. McKenney
2011-09-06 17:59 ` [PATCH tip/core/rcu 04/55] rcu: Restore checks for blocking in RCU read-side critical sections Paul E. McKenney
2011-09-06 17:59 ` [PATCH tip/core/rcu 05/55] rcu: Move rcu_head definition to types.h Paul E. McKenney
2011-09-07 18:31 ` Paul Gortmaker
2011-09-07 22:11 ` Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 06/55] rcu: Update rcutorture documentation Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 07/55] rcu: Fix mismatched variable in rcutree_trace.c Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 08/55] rcu: Abstract common code for RCU grace-period-wait primitives Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 09/55] rcu: Catch rcutorture up to new RCU API additions Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 10/55] rcu: Fix RCU's NMI documentation Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 11/55] rcu: Drive configuration directly from SMP and PREEMPT Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 12/55] rcu: Fix pathnames in documentation Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 13/55] rcu: Don't destroy rcu_torture_boost() callback until it is done Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 14/55] rcu: Add event-tracing for RCU callback invocation Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 15/55] rcu: Event-trace markers for computing RCU CPU utilization Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 16/55] rcu: Put names into TINY_RCU structures under RCU_TRACE Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 17/55] rcu: Add RCU type to callback-invocation tracing Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 18/55] rcu: Update comments to reflect softirqs vs. kthreads Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 19/55] rcu: Move RCU_BOOST declarations to allow compiler checking Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 20/55] rcu: Add event-trace markers to TREE_RCU kthreads Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 21/55] rcu: Make TINY_RCU also use softirq for RCU_BOOST=n Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 22/55] rcu: Add grace-period, quiescent-state, and call_rcu trace events Paul E. McKenney
2011-10-17 1:33 ` Josh Triplett
2011-10-24 12:02 ` Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 23/55] rcu: Simplify quiescent-state accounting Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 24/55] rcu: Not necessary to pass rcu_read_lock_held() to rcu_dereference_protected() Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 25/55] rcu: Update documentation for additional RCU lockdep functions Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 26/55] rcu: Remove unused and redundant interfaces Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 27/55] rcu: Allow rcutorture's stat_interval parameter to be changed at runtime Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 28/55] rcu: Document interpretation of RCU-lockdep splats Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 29/55] nohz: Remove nohz_cpu_mask Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 30/55] rcu: Eliminate in_irq() checks in rcu_enter_nohz() Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 31/55] rcu: Make rcu_implicit_dynticks_qs() locals be correct size Paul E. McKenney
2011-10-17 1:43 ` Josh Triplett
2011-10-24 12:00 ` Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 32/55] rcu: Make rcu_assign_pointer() unconditionally insert a memory barrier Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 33/55] rcu: Improve rcu_assign_pointer() and RCU_INIT_POINTER() documentation Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 34/55] rcu: Move __rcu_read_unlock()'s barrier() within if-statement Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 35/55] rcu: Dump local stack if cannot dump all CPUs' stacks Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 36/55] rcu: Prevent early boot set_need_resched() from __rcu_pending() Paul E. McKenney
2011-10-17 1:49 ` Josh Triplett [this message]
2011-10-24 12:07 ` Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 37/55] rcu: Simplify unboosting checks Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 38/55] rcu: Prohibit grace periods during early boot Paul E. McKenney
2011-10-17 1:51 ` Josh Triplett
2011-09-06 18:00 ` [PATCH tip/core/rcu 39/55] rcu: Suppress NMI backtraces when stall ends before dump Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 40/55] rcu: Avoid having just-onlined CPU resched itself when RCU is idle Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 41/55] rcu: Permit rt_mutex_unlock() with irqs disabled Paul E. McKenney
2011-09-18 4:09 ` Yong Zhang
2011-09-19 4:14 ` Paul E. McKenney
2011-09-19 5:49 ` Yong Zhang
2011-09-20 14:57 ` Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 42/55] rcu: Make rcu_torture_fqs() exit loops at end of test Paul E. McKenney
2011-10-17 1:53 ` Josh Triplett
2011-10-24 12:10 ` Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 43/55] rcu: Make rcu_torture_boost() " Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 44/55] rcu: wire up RCU_BOOST_PRIO for rcutree Paul E. McKenney
2011-09-13 12:02 ` Mike Galbraith
2011-09-13 15:34 ` Paul E. McKenney
2011-09-13 16:04 ` Mike Galbraith
2011-09-13 20:50 ` Paul E. McKenney
2011-10-17 1:55 ` Josh Triplett
2011-09-06 18:00 ` [PATCH tip/core/rcu 45/55] rcu: check for entering dyntick-idle mode while in read-side critical section Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 46/55] rcu: Remove rcu_needs_cpu_flush() to avoid false quiescent states Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 47/55] rcu: Move propagation of ->completed from rcu_start_gp() to rcu_report_qs_rsp() Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 48/55] powerpc: strengthen value-returning-atomics memory barriers Paul E. McKenney
2011-09-09 17:23 ` Olof Johansson
2011-09-09 17:34 ` Paul E. McKenney
2011-09-09 18:43 ` Olof Johansson
2011-09-06 18:00 ` [PATCH tip/core/rcu 49/55] rcu: Detect illegal rcu dereference in extended quiescent state Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 50/55] rcu: Inform the user about dynticks-idle mode on PROVE_RCU warning Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 51/55] rcu: Warn when rcu_read_lock() is used in extended quiescent state Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 52/55] rcu: Remove one layer of abstraction from PROVE_RCU checking Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 53/55] rcu: Warn when srcu_read_lock() is used in an extended quiescent state Paul E. McKenney
2011-10-04 21:03 ` Frederic Weisbecker
2011-10-04 23:40 ` Paul E. McKenney
2011-10-04 23:42 ` Frederic Weisbecker
2011-09-06 18:00 ` [PATCH tip/core/rcu 54/55] rcu: Make srcu_read_lock_held() call common lockdep-enabled function Paul E. McKenney
2011-10-17 2:03 ` Josh Triplett
2011-10-24 12:34 ` Paul E. McKenney
2011-09-06 18:00 ` [PATCH tip/core/rcu 55/55] powerpc: Work around tracing from dyntick-idle mode Paul E. McKenney
2011-09-07 10:00 ` Benjamin Herrenschmidt
2011-09-07 13:44 ` Paul E. McKenney
2011-09-13 19:13 ` Frederic Weisbecker
2011-09-13 19:50 ` Paul E. McKenney
2011-09-13 20:49 ` Benjamin Herrenschmidt
2011-09-15 14:53 ` Frederic Weisbecker
2011-09-16 12:24 ` Frederic Weisbecker
2011-09-07 14:39 ` [PATCH tip/core/rcu 0/55] Preview of RCU changes for 3.2 Lin Ming
2011-09-08 17:41 ` Paul E. McKenney
2011-09-08 19:23 ` Thomas Gleixner
2011-09-08 20:48 ` Paul E. McKenney
2011-09-12 16:24 ` Paul E. McKenney
2011-10-17 2:06 ` Josh Triplett
2011-10-24 12:35 ` Paul E. McKenney
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