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 D62A4C433F5 for ; Mon, 21 Mar 2022 16:47:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351407AbiCUQsb (ORCPT ); Mon, 21 Mar 2022 12:48:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233401AbiCUQsX (ORCPT ); Mon, 21 Mar 2022 12:48:23 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 766EC16D8CD for ; Mon, 21 Mar 2022 09:46:57 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id bx24-20020a17090af49800b001c6872a9e4eso10866050pjb.5 for ; Mon, 21 Mar 2022 09:46:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=V6tc3pkqZNZyKCTRozXMk87YSKEnJRwRCHnnvTYojQM=; b=qJLjA563ml8lhITs2zgrhf5rlbXm0bI3sjBmmEadv2kyKIgzHrhs52TsG5Q3CkEwAH yTbNE15rSUDyrpvTckkpN+wNAaeg2IxzpA9xLL50n93Qos3qRBJzXwLMRcTwYE3jIH0h MP9D3xDb63d9F2gY48267Ltq9pjZwOwY215R0Ca9vRgi4rYwHO8nkt0m7kVXrLshZ6oJ /MPPRk3tZQWqeUakFIbju39P0m9vw5VDuK0OpIs7w1oOjpQ5yz/+Bh0tQ8bp7j+xGTFN SMBHmqL8kQfy0ojMUPijx5S1RPlfFD8NQ2WOXuWy9Hsk+rIxfPAn1DwHqBdF20hVNhtg 5fkA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=V6tc3pkqZNZyKCTRozXMk87YSKEnJRwRCHnnvTYojQM=; b=CXxPd5evIXgVkFZWbMbMXLrj2oQV7pAl1zACWR/3qS5xEtzQkI5mThgkYLcK8ta6cn 6FdcsSFN625I3qfpDJ/dt2GAJN5sXNhnS7uhjvhrHLDYcU6Duvz6MUlwwxtjn9g75As8 YSb1R7NonB5aWBB4Jy9wfKH4RJn7M31B0H85YEijUH3ySlgA7blWF9qVlkhYCnSLtKtZ gr3RaVkD5KqFLs4ZMHsG6+vD/HXyHnVIhm/Km8X8rInRfvhW9uW6gF9g7N5yT0BYBfV2 qlznnrFbk6pwBTVc51N/1frMOZB+F1pilXOmhGDOuWISpM5En36cA6KtiKaiZeDx8hzC M1eA== X-Gm-Message-State: AOAM532uSMfqG4zCg6kKXcbjmub75Qb4ZwMNLsuOR4AmKafK+WasPX/k 6m5X1m48U+R1EadvmecX1F8= X-Google-Smtp-Source: ABdhPJw1lU/HcU+i9TJEwn7QFHAfdz7Eg7o6ONFT68y6ASLupQld+f3Hq1/sh7yxe/ZQwDtEszM2KQ== X-Received: by 2002:a17:902:e5d1:b0:154:3319:19c7 with SMTP id u17-20020a170902e5d100b00154331919c7mr11436438plf.34.1647881216780; Mon, 21 Mar 2022 09:46:56 -0700 (PDT) Received: from localhost (2603-800c-1a02-1bae-e24f-43ff-fee6-449f.res6.spectrum.com. [2603:800c:1a02:1bae:e24f:43ff:fee6:449f]) by smtp.gmail.com with ESMTPSA id 68-20020a621647000000b004fa763ef1easm11159917pfw.125.2022.03.21.09.46.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Mar 2022 09:46:55 -0700 (PDT) Sender: Tejun Heo Date: Mon, 21 Mar 2022 06:46:53 -1000 From: Tejun Heo To: Al Viro Cc: Imran Khan , gregkh@linuxfoundation.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [RESEND PATCH v7 7/8] kernfs: Replace per-fs rwsem with hashed rwsems. Message-ID: References: <20220317072612.163143-1-imran.f.khan@oracle.com> <20220317072612.163143-8-imran.f.khan@oracle.com> <536f2392-45d2-2f43-5e9d-01ef50e33126@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 21, 2022 at 07:29:45AM +0000, Al Viro wrote: ... > stabilizing the tree topology. Turn it into rwlock if you wish, > with that thing being a reader and existing users - writers. > And don't bother with further scaling, until and unless you see a real > contention on it. Given how rare these renames are, in the (unlikely) case the rename rwsem becomes a problem, we should probably just switch it to a percpu_rwsem. Thanks. -- tejun