From: Peter Zijlstra <peterz@infradead.org>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>,
linux-kernel@vger.kernel.org, tglx@linutronix.de,
torvalds@linux-foundation.org, rostedt@goodmis.org,
mark.rutland@arm.com, juri.lelli@redhat.com,
joel@joelfernandes.org, raghavendra.kt@amd.com,
sshegde@linux.ibm.com, boris.ostrovsky@oracle.com,
konrad.wilk@oracle.com, Ingo Molnar <mingo@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH v2 16/35] preempt,rcu: warn on PREEMPT_RCU=n, preempt=full
Date: Thu, 6 Jun 2024 13:53:25 +0200 [thread overview]
Message-ID: <20240606115325.GD8774@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <c6b5a5e4-e14e-4fbb-84af-75d4035ced32@paulmck-laptop>
On Thu, May 30, 2024 at 04:20:26PM -0700, Paul E. McKenney wrote:
> My selfish motivation here is to avoid testing this combination unless
> and until someone actually has a good use for it.
That doesn't make sense, the whole LAZY thing is fundamentally identical
to FULL, except it sometimes delays the preemption a wee bit. But all
the preemption scenarios from FULL are possible.
As such, it makes far more sense to only test FULL.
next prev parent reply other threads:[~2024-06-06 11:53 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-28 0:34 [PATCH v2 00/35] PREEMPT_AUTO: support lazy rescheduling Ankur Arora
2024-05-28 0:34 ` [PATCH v2 01/35] sched/core: Move preempt_model_*() helpers from sched.h to preempt.h Ankur Arora
2024-06-06 17:45 ` [tip: sched/core] " tip-bot2 for Sean Christopherson
2024-05-28 0:34 ` [PATCH v2 02/35] sched/core: Drop spinlocks on contention iff kernel is preemptible Ankur Arora
2024-05-28 0:34 ` [PATCH v2 03/35] sched: make test_*_tsk_thread_flag() return bool Ankur Arora
2024-05-28 0:34 ` [PATCH v2 04/35] preempt: introduce CONFIG_PREEMPT_AUTO Ankur Arora
2024-06-03 15:04 ` Shrikanth Hegde
2024-06-04 17:52 ` Ankur Arora
2024-05-28 0:34 ` [PATCH v2 05/35] thread_info: selector for TIF_NEED_RESCHED[_LAZY] Ankur Arora
2024-05-28 15:55 ` Peter Zijlstra
2024-05-30 9:07 ` Ankur Arora
2024-05-28 0:34 ` [PATCH v2 06/35] thread_info: define __tif_need_resched(resched_t) Ankur Arora
2024-05-28 16:03 ` Peter Zijlstra
2024-05-28 0:34 ` [PATCH v2 07/35] sched: define *_tsk_need_resched_lazy() helpers Ankur Arora
2024-05-28 16:09 ` Peter Zijlstra
2024-05-30 9:02 ` Ankur Arora
2024-05-29 8:25 ` Peter Zijlstra
2024-05-30 9:08 ` Ankur Arora
2024-05-28 0:34 ` [PATCH v2 08/35] entry: handle lazy rescheduling at user-exit Ankur Arora
2024-05-28 16:12 ` Peter Zijlstra
2024-05-28 0:34 ` [PATCH v2 09/35] entry/kvm: handle lazy rescheduling at guest-entry Ankur Arora
2024-05-28 16:13 ` Peter Zijlstra
2024-05-30 9:04 ` Ankur Arora
2024-05-28 0:34 ` [PATCH v2 10/35] entry: irqentry_exit only preempts for TIF_NEED_RESCHED Ankur Arora
2024-05-28 16:18 ` Peter Zijlstra
2024-05-30 9:03 ` Ankur Arora
2024-05-28 0:34 ` [PATCH v2 11/35] sched: __schedule_loop() doesn't need to check for need_resched_lazy() Ankur Arora
2024-05-28 0:34 ` [PATCH v2 12/35] sched: separate PREEMPT_DYNAMIC config logic Ankur Arora
2024-05-28 16:25 ` Peter Zijlstra
2024-05-30 9:30 ` Ankur Arora
2024-05-28 0:34 ` [PATCH v2 13/35] sched: allow runtime config for PREEMPT_AUTO Ankur Arora
2024-05-28 16:27 ` Peter Zijlstra
2024-05-30 9:29 ` Ankur Arora
2024-06-06 11:51 ` Peter Zijlstra
2024-06-06 15:11 ` Ankur Arora
2024-06-06 17:32 ` Peter Zijlstra
2024-06-09 0:46 ` Ankur Arora
2024-06-12 18:10 ` Paul E. McKenney
2024-05-28 0:35 ` [PATCH v2 14/35] rcu: limit PREEMPT_RCU to full preemption under PREEMPT_AUTO Ankur Arora
2024-05-28 0:35 ` [PATCH v2 15/35] rcu: fix header guard for rcu_all_qs() Ankur Arora
2024-05-28 0:35 ` [PATCH v2 16/35] preempt,rcu: warn on PREEMPT_RCU=n, preempt=full Ankur Arora
2024-05-29 8:14 ` Peter Zijlstra
2024-05-30 18:32 ` Paul E. McKenney
2024-05-30 23:05 ` Ankur Arora
2024-05-30 23:15 ` Paul E. McKenney
2024-05-30 23:04 ` Ankur Arora
2024-05-30 23:20 ` Paul E. McKenney
2024-06-06 11:53 ` Peter Zijlstra [this message]
2024-06-06 13:38 ` Paul E. McKenney
2024-06-17 15:54 ` Paul E. McKenney
2024-06-18 16:29 ` Paul E. McKenney
2024-05-28 0:35 ` [PATCH v2 17/35] rcu: handle quiescent states for PREEMPT_RCU=n, PREEMPT_COUNT=y Ankur Arora
2024-05-28 0:35 ` [PATCH v2 18/35] rcu: force context-switch " Ankur Arora
2024-05-28 0:35 ` [PATCH v2 19/35] x86/thread_info: define TIF_NEED_RESCHED_LAZY Ankur Arora
2024-05-28 0:35 ` [PATCH v2 20/35] powerpc: add support for PREEMPT_AUTO Ankur Arora
2024-05-28 0:35 ` [PATCH v2 21/35] sched: prepare for lazy rescheduling in resched_curr() Ankur Arora
2024-05-29 9:32 ` Peter Zijlstra
2024-05-28 0:35 ` [PATCH v2 22/35] sched: default preemption policy for PREEMPT_AUTO Ankur Arora
2024-05-28 0:35 ` [PATCH v2 23/35] sched: handle idle preemption " Ankur Arora
2024-05-28 0:35 ` [PATCH v2 24/35] sched: schedule eagerly in resched_cpu() Ankur Arora
2024-05-28 0:35 ` [PATCH v2 25/35] sched/fair: refactor update_curr(), entity_tick() Ankur Arora
2024-05-28 0:35 ` [PATCH v2 26/35] sched/fair: handle tick expiry under lazy preemption Ankur Arora
2024-05-28 0:35 ` [PATCH v2 27/35] sched: support preempt=none under PREEMPT_AUTO Ankur Arora
2024-05-28 0:35 ` [PATCH v2 28/35] sched: support preempt=full " Ankur Arora
2024-05-28 0:35 ` [PATCH v2 29/35] sched: handle preempt=voluntary " Ankur Arora
2024-06-17 3:20 ` Tianchen Ding
2024-06-21 18:58 ` Ankur Arora
2024-06-24 2:35 ` Tianchen Ding
2024-06-25 1:12 ` Ankur Arora
2024-06-26 2:43 ` Tianchen Ding
2024-05-28 0:35 ` [PATCH v2 30/35] sched: latency warn for TIF_NEED_RESCHED_LAZY Ankur Arora
2024-05-28 0:35 ` [PATCH v2 31/35] tracing: support lazy resched Ankur Arora
2024-05-28 0:35 ` [PATCH v2 32/35] Documentation: tracing: add TIF_NEED_RESCHED_LAZY Ankur Arora
2024-05-28 0:35 ` [PATCH v2 33/35] osnoise: handle quiescent states for PREEMPT_RCU=n, PREEMPTION=y Ankur Arora
2024-05-28 13:12 ` Daniel Bristot de Oliveira
2024-05-28 0:35 ` [PATCH v2 34/35] kconfig: decompose ARCH_NO_PREEMPT Ankur Arora
2024-05-28 0:35 ` [PATCH v2 35/35] arch: " Ankur Arora
2024-05-29 6:16 ` [PATCH v2 00/35] PREEMPT_AUTO: support lazy rescheduling Shrikanth Hegde
2024-06-01 11:47 ` Ankur Arora
2024-06-04 7:32 ` Shrikanth Hegde
2024-06-07 16:48 ` Shrikanth Hegde
2024-06-10 7:23 ` Ankur Arora
2024-06-15 15:04 ` Shrikanth Hegde
2024-06-18 18:27 ` Shrikanth Hegde
2024-06-19 2:40 ` Ankur Arora
2024-06-24 18:37 ` Shrikanth Hegde
2024-06-27 2:50 ` Ankur Arora
2024-06-27 5:56 ` Michael Ellerman
2024-06-27 15:44 ` Shrikanth Hegde
2024-07-03 5:27 ` Ankur Arora
2024-08-12 17:32 ` Shrikanth Hegde
2024-08-12 21:07 ` Linus Torvalds
2024-08-13 5:40 ` Ankur Arora
2024-06-05 15:44 ` Sean Christopherson
2024-06-05 17:45 ` Peter Zijlstra
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