Received: by 2002:a05:6a11:4021:0:0:0:0 with SMTP id ky33csp596548pxb; Tue, 14 Sep 2021 04:47:58 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwIQ1RmZD7ledjfZPAvtJacreQgju2g4V+XQF8htvKLlhaZ1K68cP5WT1OcxQ9LSFVICFD+ X-Received: by 2002:a5d:8d1a:: with SMTP id p26mr13406473ioj.141.1631620078303; Tue, 14 Sep 2021 04:47:58 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1631620078; cv=none; d=google.com; s=arc-20160816; b=s6iTXnP0hbHDyUye2vluBsG7DpMG8xe8FiwDfF30f71pBafuam/7NIyCApE/pPuB6V kmdsidZ9oREft1XxsjXMgGUBFuxoJ94P/tlXFz1amhKa23eRIHHm3QobUuOiv8J/kQEi NZm6aNJ/P1C4ipciGm/PYNqi1CSJMxBWlu2fqLtzt2esDhQdlHiQ2hjV754CWWw2+fEw x3468Ox6snZDiSZ01Xvv3OWZsvWCAnY7O7tj3xhVGCLkbaicQ66wdyE2zbzO1beSZJJd JKQdDikttZuU9gpFHcSUzl4QeMo0s1Q6e1yIxP/ye1XqSrC1vbwUzd+8yJx+9L52XQmf PkeA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature; bh=uzhBfondxfBGtuI3LygrN3vuHuB3wvkg/TeMLODJ0wY=; b=Ud1LENnINQYM6QCXV7Iutg/sYTe1gU1NWSCulrvPY70cPhvBahik9fTRAgiCH6UA3M 65pzYgZOmoFQKlDdoonG4EubKoT7OCLxCDIrz6v1vFC+D97vBA3cb8OaSnrFLtZb6Wj1 KxHXOngjSZ5A34MvfPy/11fRx5aypVaFZGEzRwYBbAR4ojPIu8809klYKHQL/5upIn+2 L7tS9Zx3fYjkYD+xhqg2hnua0fayrT1cnRvnU3EPJMMGSvsnne2saR5n+CXp96IWCvxO yPfhH4ByrHTk8qIxiO/4VPml0Mjo9sVKgFGBqwHTdkGweBfzzdcJAzgBZ6ovgk28Cfsv pSVw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=C1rG6AaP; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id x19si8953575ilc.166.2021.09.14.04.47.46; Tue, 14 Sep 2021 04:47:58 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=C1rG6AaP; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232187AbhINLr6 (ORCPT + 99 others); Tue, 14 Sep 2021 07:47:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232065AbhINLr4 (ORCPT ); Tue, 14 Sep 2021 07:47:56 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02488C061574; Tue, 14 Sep 2021 04:46:39 -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=uzhBfondxfBGtuI3LygrN3vuHuB3wvkg/TeMLODJ0wY=; b=C1rG6AaPuDMXGAqNsCuVsPTyRa huaJs1/AX27R0/mALFdUg4TtGIFar2KEeR9vyHbORinJ8afxMHfkSK1d4y0PnhIO2Lr0NLdhASmAu /xftc4aFN93KUmihSCWnYYf6+fUSY8Ds2Lg5EDWShlMwbqnZLqTixJTsRZrtPTqC3x/0KTFzOkc9t TJA0nOljNRPiLbNVzBGc+HhUGET1W3iXPag36hIvixUtIjGBKF1HEmDMuc8nKpGKYd01fi4Y1/jPc 91Pj9BFDSMk9jlt5Fh06nvDDjJpw/YzT7tX2nAENqkFqr9pTo+L8fHn9G/s9l61zgoIjfF3Sr2q6/ HMGG1a/w==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mQ6sO-00EcLs-Gk; Tue, 14 Sep 2021 11:45:40 +0000 Date: Tue, 14 Sep 2021 12:45:24 +0100 From: Christoph Hellwig To: Hamza Mahfooz Cc: linux-kernel@vger.kernel.org, Benjamin LaHaise , Alexander Viro , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] aio: convert active_reqs into a hashtable Message-ID: References: <20210914094625.171211-1-someguy@effective-light.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210914094625.171211-1-someguy@effective-light.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 14, 2021 at 05:46:25AM -0400, Hamza Mahfooz wrote: > Commit 833f4154ed56 ("aio: fold lookup_kiocb() into its sole caller") > suggests that, the fact that active_reqs is a linked-list means aio_kiocb > lookups in io_cancel() are inefficient. So, to get faster lookups (on > average) while maintaining similar insertion and deletion characteristics, > turn active_reqs into a hashtable. What workload cares about AIO cancellation performance?