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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D17BEB64DD for ; Wed, 12 Jul 2023 09:32:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229987AbjGLJcF (ORCPT ); Wed, 12 Jul 2023 05:32:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233133AbjGLJb6 (ORCPT ); Wed, 12 Jul 2023 05:31:58 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3525170E; Wed, 12 Jul 2023 02:31:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=1NES0FBGbCJEuBDLLpuM1qLJflryX6djz/7RZ/xzrDM=; b=BlrY/whatP2X2PV+0WGmmBqDBf dxu95sAXYZQQFWopDgpYejmAN+hVRNDFPxjaIT30vS8iYjSkFLKp+amG4tChZyx1y2BbqpwL5sFVX kvuHpeqnzeKTk7WrEDaIhjqCQH34Wot5Yf9+oJLZEBlmRuyQ3ri/M4ROGnBC+y+B1/my6cvK5LE7O tU0oDoRsuZwL/ZzvGMZv+8CghkFgoVg1XRNfIFl6FLBtlmbZym5isY8019eo41bfl5m5+mxeGfu88 +ui9fIn/0SRHUJNZyxIbRtR4c8u869tM2BESxy57ND+Les2UKgsLvXPxnt3dkJVnQbwBjXX1TWpkH TW+2uXNA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qJWCP-00GXcO-NZ; Wed, 12 Jul 2023 09:31:53 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id DD15630036B; Wed, 12 Jul 2023 11:31:52 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C6A0A2440832A; Wed, 12 Jul 2023 11:31:52 +0200 (CEST) Date: Wed, 12 Jul 2023 11:31:52 +0200 From: Peter Zijlstra To: Jens Axboe Cc: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com Subject: Re: [PATCH 7/7] io_uring: add futex waitv Message-ID: <20230712093152.GF3100107@hirez.programming.kicks-ass.net> References: <20230712004705.316157-1-axboe@kernel.dk> <20230712004705.316157-8-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230712004705.316157-8-axboe@kernel.dk> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 11, 2023 at 06:47:05PM -0600, Jens Axboe wrote: > Needs a bit of splitting and a few hunks should go further back (like > the wake handler typedef). > > WIP, adds IORING_OP_FUTEX_WAITV - pass in an array of futex addresses, > and wait on all of them until one of them triggers. > So I'm once again not following. FUTEX_WAITV is to wait on multiple futexes and get a notification when any one of them wakes up with an index to indicate which one. How exactly is that different from multiple FUTEX_WAIT entries in the io_uring thing itself? Admittedly I don't actually know much of anything when it comes to io_uring, but isn't the idea that queue multiple 'syscall' like things and get individual completions back? So how does WAITV make sense here?