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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 C2119C432C3 for ; Fri, 15 Nov 2019 17:15:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9324520728 for ; Fri, 15 Nov 2019 17:15:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QUbG1FRk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727620AbfKORO7 (ORCPT ); Fri, 15 Nov 2019 12:14:59 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:48378 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727548AbfKORO7 (ORCPT ); Fri, 15 Nov 2019 12:14:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573838098; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=i//VdLznyJQ1f9EYHUzbZrmnX/uwUJtCHfRMoEiRRFM=; b=QUbG1FRkgiruETIr+rJqo4Q7IA89FwWUFX0oGpDRZiyB0khjdgglhnEOBOTF/xUDiikFTS fkFl4TfdPeOPXPUqP3E8XNN+eO1qE/x3zz+s92U6BpKfeOzCUcsg+Gw+W1HQYPeeB7Kv4S uIDRGj3uuq5B9ogg5xILALUQ2O8jcas= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-402-bn7BejAKOU--lJSVYPquaA-1; Fri, 15 Nov 2019 12:14:55 -0500 Received: by mail-wm1-f69.google.com with SMTP id h191so7301474wme.5 for ; Fri, 15 Nov 2019 09:14:54 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=fkKZc7EVVIK/btwaEMMtK6umsKN2KQyJVj0fen7NWM4=; b=KnuLg+GIbDkXHQByTygxYXvHguSZaLsYVEXJ42dZn2pwclIuKV23/9yBZYrux25fWQ h1oTWtFgspEdUwYa3UI20EExT5289gSLh14xY1npmv6CYYnbsUDRA105EqTBAR50d4N5 gzX5a2/GD/7HoW3c2h/ALKfuHUFQftfnXRz0BUhia8OyrsCMjcJqzeD2jyMF8me2/t4V mtQ/YqCkSV6xHAKmDV1DanBdQCIbTXvQShLg5caiUXtecI8i5CAVN2m7EVQySMz5SSQS QB4c13YBPD7f0fX/wmEFiDDMlH3/sIlwoGej8qiW4SYsxTY5W4nrKSKo4DvE81NcAASx A1Aw== X-Gm-Message-State: APjAAAUtb3FSZgpko1o+lEbjyhbfjfAdYdInUNtD3QY9ViohZPzT/5ju /EX/OW/NQKKuwRC0E0tvhj/NB0AdjzPsrv6zMYvZ9yd4O37Wyah1SdTbcm4yEq4aW6H6Lee6XK5 44QGBSvCiMcg766cCBYWRGBLq X-Received: by 2002:a1c:7709:: with SMTP id t9mr15737398wmi.80.1573838093812; Fri, 15 Nov 2019 09:14:53 -0800 (PST) X-Google-Smtp-Source: APXvYqzFYsvAwIE6O5TRg5h8L4op6aHWHNgR4Qnu7Nap2afcKOa3ebQhqU+/jSY5LlHI0javOU1nhQ== X-Received: by 2002:a1c:7709:: with SMTP id t9mr15737362wmi.80.1573838093545; Fri, 15 Nov 2019 09:14:53 -0800 (PST) Received: from localhost.localdomain ([151.29.177.194]) by smtp.gmail.com with ESMTPSA id a6sm13758352wrh.69.2019.11.15.09.14.52 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 15 Nov 2019 09:14:52 -0800 (PST) Date: Fri, 15 Nov 2019 18:14:50 +0100 From: Juri Lelli To: Peter Zijlstra Cc: mingo@kernel.org, will@kernel.org, oleg@redhat.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, bigeasy@linutronix.de, williams@redhat.com, bristot@redhat.com, longman@redhat.com, dave@stgolabs.net, jack@suse.com Subject: Re: [PATCH 0/5] locking: Percpu-rwsem rewrite Message-ID: <20191115171450.GJ19129@localhost.localdomain> References: <20191113102115.116470462@infradead.org> MIME-Version: 1.0 In-Reply-To: <20191113102115.116470462@infradead.org> User-Agent: Mutt/1.11.3 (2019-02-01) X-MC-Unique: bn7BejAKOU--lJSVYPquaA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 13/11/19 11:21, Peter Zijlstra wrote: > Yet another version of the percpu-rwsem rewrite.. >=20 > This one (ab)uses the waitqueue in an entirely different and unique way, = but no > longer shares it like it did. It retains the use of rcuwait for the > writer-waiting-for-readers-to-complete condition. >=20 > This one should be FIFO fair with writer-stealing. >=20 > It seems to pass locktorture torture_type=3Dpercpu_rwsem_lock. But as alw= ays, > this stuff is tricky, please look carefully. Backported this series to v5.2.21-rt13. locktorture looks good (running for several hours) and DEBUG_LOCKS splat [1] not reproducible anymore. Tested-by: Juri Lelli Thanks! Juri 1 - https://lore.kernel.org/lkml/20190326093421.GA29508@localhost.localdoma= in/