From: valdis.kletnieks@vt.edu
To: Waiman Long <longman@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Jonathan Corbet <corbet@lwn.net>,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Mike Galbraith <umgwanakikbuti@gmail.com>,
Scott J Norton <scott.norton@hpe.com>
Subject: Re: [PATCH-tip v5 17/21] TP-futex: Group readers together in wait queue
Date: Fri, 03 Feb 2017 14:26:57 -0500 [thread overview]
Message-ID: <18211.1486150017@turing-police.cc.vt.edu> (raw)
In-Reply-To: <275d5112-eaa8-1158-b26d-4e18c8bf79e1@redhat.com>
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On Fri, 03 Feb 2017 13:42:46 -0500, Waiman Long said:
> This patch set does guarantee some minimum performance level, but it
> can't guarantee fairness for all the lock waiters.
OK, sounds like it's a situation that's statistically unlikely, but it has
protections against starvation so the system will eventually dig itself out of
the hole, and the scenario is at least known and understood. The improved
numbers for average-case probably outweigh the worst-case then...
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next prev parent reply other threads:[~2017-02-03 19:27 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-03 18:03 [PATCH-tip v5 00/21] futex: Introducing throughput-optimized (TP) futexes Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 01/21] perf bench: New microbenchmark for userspace mutex performance Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 02/21] perf bench: New microbenchmark for userspace rwlock performance Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 03/21] futex: Consolidate duplicated timer setup code Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 04/21] futex: Rename futex_pi_state to futex_state Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 05/21] futex: Add helpers to get & cmpxchg futex value without lock Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 06/21] futex: Consolidate pure pi_state_list add & delete codes to helpers Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 07/21] futex: Add a new futex type field into futex_state Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 08/21] futex: Allow direct attachment of futex_state objects to hash bucket Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 09/21] futex: Introduce throughput-optimized (TP) futexes Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 10/21] TP-futex: Enable robust handling Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 11/21] TP-futex: Implement lock handoff to prevent lock starvation Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 12/21] TP-futex: Return status code on FUTEX_LOCK calls Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 13/21] TP-futex: Add timeout support Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 14/21] TP-futex, doc: Add TP futexes documentation Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 15/21] TP-futex: Support userspace reader/writer locks Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 16/21] TP-futex: Enable kernel reader lock stealing Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 17/21] TP-futex: Group readers together in wait queue Waiman Long
2017-02-03 18:23 ` valdis.kletnieks
2017-02-03 18:42 ` Waiman Long
2017-02-03 19:26 ` valdis.kletnieks [this message]
2017-02-03 18:03 ` [PATCH-tip v5 18/21] TP-futex, doc: Update TP futexes document on shared locking Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 19/21] perf bench: Extend mutex/rwlock futex suite to test TP futexes Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 20/21] sched, TP-futex: Make wake_up_q() return wakeup count Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 21/21] futex: Dump internal futex state via debugfs Waiman Long
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