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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 82E4AC47404 for ; Fri, 4 Oct 2019 16:20:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5914920873 for ; Fri, 4 Oct 2019 16:20:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jzQxpEXu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390222AbfJDQUy (ORCPT ); Fri, 4 Oct 2019 12:20:54 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:38620 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390152AbfJDQUy (ORCPT ); Fri, 4 Oct 2019 12:20:54 -0400 Received: by mail-lj1-f196.google.com with SMTP id b20so7118301ljj.5; Fri, 04 Oct 2019 09:20:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=esA6+awGjiFzCbqVXjFrVJ00nRBU2EYyMDWs4D5Bo9k=; b=jzQxpEXu981x/R4lBeyi37dR9lNATiNXvQIQcX78AibLePSTwnTPgExbDqvKaaQWLq LrdMMMlPpdr1jBSuzh+AirY9496WZnUkB9RFQVv/ZEo0d/FBrzRtGplxVVs/nH+Zdtht fNWc7yRznWVaRwrgsAcyyqtj9YUb45VG23pbp4+8okBiworkHUejExjulGgOTeP/eQx4 isJnZMNNvHIriF+u5m1xgDYFE2EEG5/qLAug/AMUcMciutF5q4V4wLTwoYqRiWgw728p w421te/O6o8DZMGLkiEjt5iw/hjGex7J5N+AfTHMs0Az1CatAJc0KMiSeuqAtgxRH3P3 xeHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=esA6+awGjiFzCbqVXjFrVJ00nRBU2EYyMDWs4D5Bo9k=; b=mXBgJMhPwjvGZO6qHcX9MfvXeWiMbdbs6s0VEDvHG1LnswcyCpHgGgFlbaJZvTHdXA YbOip6wHfZhPGO0KpAHzK5asjewWlkLIZ1y+4964rSgZRDF1b4VibIunZSlHB8cixA50 iNl2+NLFip+EueTR5/QV8TCwIhhGgWJGEos5mdv9mvZYOMj8qsY/TuL3hVIy58HeVR4y q2ayE3GcKNNuuB3EDS7kcKvc7rGLoczIxL3WWwTo0RfnTC/lFfHYNgXW/y8KzlrayK3Y vOdyd/jO/j5f+VTWGTw6HavaOCOur3/eexRrNB2GZ0L+oMDWvbO1cRebHO55ICzj66tJ +XIA== X-Gm-Message-State: APjAAAVrc/UxinJhkBeENOsxI/ofn7/cLUNViQvl+RVCP9p0gfaTXWoS U1/kcMpP5otJS1vMM23I5qI= X-Google-Smtp-Source: APXvYqx5KFDU3H6pNRjg1NQbE6teRhCUB8J57fMUlIj1AcLch3+TZ7ihEN7H5oa8mKxdRpgD6cquTw== X-Received: by 2002:a2e:9d44:: with SMTP id y4mr10224990ljj.115.1570206050168; Fri, 04 Oct 2019 09:20:50 -0700 (PDT) Received: from pc636 ([37.139.158.167]) by smtp.gmail.com with ESMTPSA id q19sm1341149ljj.73.2019.10.04.09.20.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Oct 2019 09:20:48 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Fri, 4 Oct 2019 18:20:41 +0200 To: Sebastian Andrzej Siewior Cc: Daniel Wagner , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, Andrew Morton , Uladzislau Rezki Subject: Re: [PATCH] mm: vmalloc: Use the vmap_area_lock to protect ne_fit_preload_node Message-ID: <20191004162041.GA30806@pc636> References: <20191003090906.1261-1-dwagner@suse.de> <20191004153728.c5xppuqwqcwecbe6@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191004153728.c5xppuqwqcwecbe6@linutronix.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Fri, Oct 04, 2019 at 05:37:28PM +0200, Sebastian Andrzej Siewior wrote: > If you post something that is related to PREEMPT_RT please keep tglx and > me in Cc. > > On 2019-10-03 11:09:06 [+0200], Daniel Wagner wrote: > > Replace preempt_enable() and preempt_disable() with the vmap_area_lock > > spin_lock instead. Calling spin_lock() with preempt disabled is > > illegal for -rt. Furthermore, enabling preemption inside the > > Looking at it again, I have reasonable doubt that this > preempt_disable() is needed. > The intention was to preload a current CPU with one extra object in non-atomic context, thus to use GFP_KERNEL permissive parameters. I.e. that allows us to avoid any allocation(if we stay on the same CPU) when we are in atomic context do splitting. If we have migrate_disable/enable, then, i think preempt_enable/disable should be replaced by it and not the way how it has been proposed in the patch. -- Vlad Rezki