* Re: [tip:core/urgent] rcu: avoid pointless blocked-task warnings [not found] <tip-b24efdfdf679cf9b05947c531971905fc727dd40@git.kernel.org> @ 2011-01-15 14:28 ` Ingo Molnar 2011-01-16 0:15 ` Paul E. McKenney 0 siblings, 1 reply; 2+ messages in thread From: Ingo Molnar @ 2011-01-15 14:28 UTC (permalink / raw) To: linux-kernel, mingo, hpa, paul.mckenney, rmk+kernel, weber, paulmck, tglx Cc: linux-tip-commits * tip-bot for Paul E. McKenney <paul.mckenney@linaro.org> wrote: > Commit-ID: b24efdfdf679cf9b05947c531971905fc727dd40 > Gitweb: http://git.kernel.org/tip/b24efdfdf679cf9b05947c531971905fc727dd40 > Author: Paul E. McKenney <paul.mckenney@linaro.org> > AuthorDate: Wed, 12 Jan 2011 14:18:11 -0800 > Committer: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > CommitDate: Fri, 14 Jan 2011 04:58:08 -0800 > > rcu: avoid pointless blocked-task warnings > > If the RCU callback-processing kthread has nothing to do, it parks in > a wait_event(). If RCU remains idle for more than two minutes, the > kernel complains about this. This commit changes from wait_event() > to wait_event_interruptible() to prevent the kernel from complaining > just because RCU is idle. Btw., a sidenote, it's not just about the blocked-tasks lockup detector warning, uninterruptible sleeps will also artificially inflate the load average of the box, +1.0 per such task. So it's definitely a bug to sleep for a very long time uninterruptible. Thanks, Ingo ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [tip:core/urgent] rcu: avoid pointless blocked-task warnings 2011-01-15 14:28 ` [tip:core/urgent] rcu: avoid pointless blocked-task warnings Ingo Molnar @ 2011-01-16 0:15 ` Paul E. McKenney 0 siblings, 0 replies; 2+ messages in thread From: Paul E. McKenney @ 2011-01-16 0:15 UTC (permalink / raw) To: Ingo Molnar Cc: linux-kernel, mingo, hpa, paul.mckenney, rmk+kernel, weber, tglx, linux-tip-commits On Sat, Jan 15, 2011 at 03:28:57PM +0100, Ingo Molnar wrote: > > * tip-bot for Paul E. McKenney <paul.mckenney@linaro.org> wrote: > > > Commit-ID: b24efdfdf679cf9b05947c531971905fc727dd40 > > Gitweb: http://git.kernel.org/tip/b24efdfdf679cf9b05947c531971905fc727dd40 > > Author: Paul E. McKenney <paul.mckenney@linaro.org> > > AuthorDate: Wed, 12 Jan 2011 14:18:11 -0800 > > Committer: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > > CommitDate: Fri, 14 Jan 2011 04:58:08 -0800 > > > > rcu: avoid pointless blocked-task warnings > > > > If the RCU callback-processing kthread has nothing to do, it parks in > > a wait_event(). If RCU remains idle for more than two minutes, the > > kernel complains about this. This commit changes from wait_event() > > to wait_event_interruptible() to prevent the kernel from complaining > > just because RCU is idle. > > Btw., a sidenote, it's not just about the blocked-tasks lockup detector warning, > uninterruptible sleeps will also artificially inflate the load average of the box, > +1.0 per such task. So it's definitely a bug to sleep for a very long time > uninterruptible. Good point, and I have made the corresponding change in the in-progress TREE_PREEMPT_RCU variant of RCU priority boosting. Some thought will be required when merging SRCU into the Tiny and Tree RCU implementations. ;-) Thanx, Paul ^ permalink raw reply [flat|nested] 2+ messages in thread
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[not found] <tip-b24efdfdf679cf9b05947c531971905fc727dd40@git.kernel.org>
2011-01-15 14:28 ` [tip:core/urgent] rcu: avoid pointless blocked-task warnings Ingo Molnar
2011-01-16 0:15 ` Paul E. McKenney
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