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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
	jiangshanlai@gmail.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
	josh@joshtriplett.org, tglx@linutronix.de, rostedt@goodmis.org,
	dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com,
	oleg@redhat.com, joel.opensrc@gmail.com
Subject: Re: [PATCH tip/core/rcu 06/22] rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs()
Date: Mon, 23 Apr 2018 05:32:23 -0700	[thread overview]
Message-ID: <20180423123223.GK26088@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180423085347.GS4064@hirez.programming.kicks-ass.net>

On Mon, Apr 23, 2018 at 10:53:47AM +0200, Peter Zijlstra wrote:
> On Sun, Apr 22, 2018 at 07:32:11PM -0700, Paul E. McKenney wrote:
> > Commit e31d28b6ab8f ("trace: Eliminate cond_resched_rcu_qs() in favor
> > of cond_resched()") substituted cond_resched() for the earlier call
> > to cond_resched_rcu_qs().  However, the new-age cond_resched() does
> > not do anything to help RCU-tasks grace periods because (1) RCU-tasks
> > is only enabled when CONFIG_PREEMPT=y and (2) cond_resched() is a
> > complete no-op when preemption is enabled.  This situation results
> > in hangs when running the trace benchmarks.
> 
> But a few patches earlier you tried to address that..

Yes.  And all this patch does is change the name to better match
what this primitive actually does.

I could merge the two patches, if that would help.

							Thanx, Paul

  reply	other threads:[~2018-04-23 12:31 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-23  2:31 [PATCH tip/core/rcu 0/22] Miscellaneous fixes for v4.18 Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 01/22] sched: Make non-production PREEMPT cond_resched() help Tasks RCU Paul E. McKenney
2018-04-23  8:51   ` Peter Zijlstra
2018-04-23 12:40     ` Paul E. McKenney
2018-04-23 13:47       ` Steven Rostedt
2018-04-23 14:10         ` Peter Zijlstra
2018-04-23 14:35           ` Steven Rostedt
2018-04-23 15:47             ` Paul E. McKenney
2018-04-23 19:12               ` Paul E. McKenney
2018-04-23 14:03       ` Peter Zijlstra
2018-04-23  2:32 ` [PATCH tip/core/rcu 02/22] rcu: Inline rcu_preempt_do_callback() into its sole caller Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 03/22] rcu: Don't allocate rcu_nocb_mask if no one needs it Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 04/22] rcu: Call wake_nocb_leader_defer() with 'FORCE' when nocb_q_count is high Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 05/22] rcu: Remove deprecated RCU debugfs tracing code Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 06/22] rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs() Paul E. McKenney
2018-04-23  8:53   ` Peter Zijlstra
2018-04-23 12:32     ` Paul E. McKenney [this message]
2018-04-23 12:48       ` Peter Zijlstra
2018-04-23 13:12         ` Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 07/22] softirq: Eliminate unused cond_resched_softirq() macro Paul E. McKenney
2018-04-23  8:54   ` Peter Zijlstra
2018-04-23 13:25     ` Eric Dumazet
2018-04-23 19:10       ` Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 08/22] rcu: Move __rcu_read_lock() and __rcu_read_unlock() to tree_plugin.h Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 09/22] rcu: Update rcu_bind_gp_kthread() header comment Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 10/22] rcu: Declare rcu_eqs_special_set() in public header Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 11/22] srcu: Add cleanup_srcu_struct_quiesced() Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 12/22] nvme: Avoid flush dependency in delete controller flow Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 13/22] rcu: Exclude near-simultaneous RCU CPU stall warnings Paul E. McKenney
2018-05-03 18:22   ` Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 14/22] rcu: Add leaf-node macros Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 15/22] doc: Ensure whatisRCU.txt actually says what RCU is Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 16/22] EXP: rcu: Add debugging info to assertion Paul E. McKenney
2018-05-03 18:23   ` Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 17/22] EXP: rcu: Abstract addition of debugging information " Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 18/22] EXP: rcu: Add ->boost_tasks " Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 19/22] EXP: rcu: Add debugging info to other assertion Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 20/22] EXP rcu: Add ->qsmask to assertion Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 21/22] EXP rcu: Add checks for setting ->gp_flags Paul E. McKenney
2018-04-23  2:32 ` [PATCH tip/core/rcu 22/22] rcu: Use the proper lockdep annotation in dump_blkd_tasks() Paul E. McKenney

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