From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2929BC433DB for ; Mon, 8 Mar 2021 16:19:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8E026521F for ; Mon, 8 Mar 2021 16:19:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230143AbhCHQSq (ORCPT ); Mon, 8 Mar 2021 11:18:46 -0500 Received: from mail.codeweavers.com ([50.203.203.244]:50380 "EHLO mail.codeweavers.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230440AbhCHQSe (ORCPT ); Mon, 8 Mar 2021 11:18:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=codeweavers.com; s=6377696661; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=RmNhH5XRUuG3UKqdqRAk2ui+eZgYvhYalUYwnX71Zk0=; b=kS52GJXBfoLqcsm0bQi3+gnsis E1MCGH5z67nXrZMNX0E2lDQ3VK9yevVudpCJpLA90DM1/rPQq6fbBcJAumwhff+rR+gW/2bm+aJ3I yfnYJwLObFRwvIkuKgJRHUwi3FDXQq85J1UOd1kkseYu/4J/p/XMUsEJI8wbHjg2ybPY=; 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 Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org 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/