From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.codeweavers.com (mail.codeweavers.com [50.203.203.244]) by sourceware.org (Postfix) with ESMTPS id 1FFD83860C3B for ; Mon, 8 Mar 2021 16:18:34 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 1FFD83860C3B Received: from [10.69.139.34] by mail.codeweavers.com with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1lJIaU-0003bZ-9h; Mon, 08 Mar 2021 10:18:30 -0600 Subject: Re: [RFC PATCH v2 00/13] Add futex2 syscall To: =?UTF-8?Q?Andr=c3=a9_Almeida?= , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , linux-kernel@vger.kernel.org, Steven Rostedt , Sebastian Andrzej Siewior Cc: kernel@collabora.com, krisman@collabora.com, pgriffais@valvesoftware.com, joel@joelfernandes.org, malteskarupke@fastmail.fm, linux-api@vger.kernel.org, fweimer@redhat.com, libc-alpha@sourceware.org, linux-kselftest@vger.kernel.org, shuah@kernel.org, acme@kernel.org, corbet@lwn.net References: <20210304004219.134051-1-andrealmeid@collabora.com> From: Zebediah Figura Message-ID: <2421ca75-5688-61c6-c0ac-02e55e7272a3@codeweavers.com> Date: Mon, 8 Mar 2021 10:18:29 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210304004219.134051-1-andrealmeid@collabora.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, KAM_MANYTO, NICE_REPLY_A, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Mar 2021 16:18:36 -0000 On 3/3/21 6:42 PM, André Almeida wrote: > ** The wait on multiple problem > > The use case lies in the Wine implementation of the Windows NT interface > WaitMultipleObjects. This Windows API function allows a thread to sleep > waiting on the first of a set of event sources (mutexes, timers, signal, > console input, etc) to signal. Considering this is a primitive > synchronization operation for Windows applications, being able to quickly > signal events on the producer side, and quickly go to sleep on the > consumer side is essential for good performance of those running over Wine. It's probably worth pointing out, for better or for worse, while this is *a* use case, it's also limited to an out-of-tree patch set/forked versions of Wine. I'm currently working on a different approach that should be upstreamable to Wine proper, as detailed in [1]. [1] https://lore.kernel.org/lkml/f4cc1a38-1441-62f8-47e4-0c67f5ad1d43@codeweavers.com/