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 9B0FAC433EF for ; Tue, 26 Apr 2022 22:58:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355963AbiDZXB4 (ORCPT ); Tue, 26 Apr 2022 19:01:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244571AbiDZXBz (ORCPT ); Tue, 26 Apr 2022 19:01:55 -0400 Received: from mail-yw1-x1134.google.com (mail-yw1-x1134.google.com [IPv6:2607:f8b0:4864:20::1134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACFCB67D36 for ; Tue, 26 Apr 2022 15:58:46 -0700 (PDT) Received: by mail-yw1-x1134.google.com with SMTP id 00721157ae682-2f16645872fso649167b3.4 for ; Tue, 26 Apr 2022 15:58:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=L4eqHWSN42ueWZ89KsFRMnxsq+gg1YBjDPu+hpKQi3A=; b=mvx4yW7S0NUOQCD9L2yGJOy9tKusa3h5GHrRZ0OExjnpg1PH+Wlsh4dxjojG7q43zT EABQ+Av3CJ/9HnJFry9Y3iZl0h7GGIc6GqlELDC3mXdLpEapGlb3RlCsc7zBDBVEAtO7 6yFi6IGWA5rzL09NkX+GiT19A2OeHKq4p0TAKcPNd5WxPOA8p9dG2rVUcj9tJrpoNhjr 3D9hSXSK2CPFTQWQkvQlgFDQx6bl/GD/YlZXLt4mL5D16cceSy0wYeINzZQrIgfaxWJh GVz/dAjTVacyio2J6cy02tPjnzJFGU2oSoxm5kOA8cLP7Vi8kTa29zd77IyhPiROpFgd yy1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=L4eqHWSN42ueWZ89KsFRMnxsq+gg1YBjDPu+hpKQi3A=; b=5CUsHFHnNmSRrAfy7jwaD3A6H8YQMFCec0Wdvrz9NsVYILMbIVR6QgUd0WDzIDhkCy BhyH/F5W3xI9xz+69jZSS7s8V8oXdgjEzTF1up+ohwH3FzJwHVOlzYxjkrQBpAGnyDrV 8nHuB4rTlSWPoYdHCx7cHofEI5hejzzNtXbAl3g4+QDbh4HspW1iHKnn1xxfVgJZ0Ilp 5XKqI4ZTTHHIDqbzB3YGNuV8qrzJS44tlAvvGvEVUn65k9lLiQNXIUtCeg3EYZKbLAzj yqrNEJetEExTi73fLz7uRCXtY3MSPWcQVaaR9vLaO9Y9Ln9sOFATqiv101qS9rrpC/ds OyGQ== X-Gm-Message-State: AOAM5321L6fGGYBgrA15rLJCZYCpHTaMtF9rORdSd/WrKaoQEUf/1k59 qDdgb8yqlqIC0dVHDAVClHDyjm7SRz/QoCEGCK+4 X-Google-Smtp-Source: ABdhPJxcB8JiZrX3abrVoRVZptJtZb+xka4JrPXoQU9HvLnqTul9wm0iSxbDZDgm23+xs5WBvnb7TrWAwgDIYXas1f0= X-Received: by 2002:a81:1a4a:0:b0:2f7:da21:ec5c with SMTP id a71-20020a811a4a000000b002f7da21ec5cmr13587990ywa.312.1651013925644; Tue, 26 Apr 2022 15:58:45 -0700 (PDT) MIME-Version: 1.0 References: <8E281DF1-248F-4861-A3C0-2573A5EFEE61@fb.com> <20220426065917.3123488-1-bartoschek@google.com> <20220426140919.GD4285@paulmck-ThinkPad-P17-Gen-1> In-Reply-To: <20220426140919.GD4285@paulmck-ThinkPad-P17-Gen-1> From: Christoph Bartoschek Date: Wed, 27 Apr 2022 00:58:34 +0200 Message-ID: Subject: Re: [PATCH RFC fs/namespace] Make kern_unmount() use synchronize_rcu_expedited() To: paulmck@kernel.org Cc: Chris Mason , Giuseppe Scrivano , linux-kernel@vger.kernel.org, "riel@surriel.com" , "viro@zeniv.linux.org.uk" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > 3. https://lore.kernel.org/lkml/20220218183114.2867528-1-riel@surriel.com/ > Refined queue_rcu_work() approach. > > #1 should work, but the resulting IPIs are not going to make the real-time > guys happy. #2 and #3 have been subject to reasonably heavy testing > and did fix a very similar issue to the one that you are reporting, > but last I knew there were doubts about the concurrency consequences. > > Could you please give at least #3 a shot and see if it helps you? > I have tried #3 and it works well with my testcases as far as I can see it. Christoph