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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 EDAB5C2D0A3 for ; Thu, 29 Oct 2020 09:42:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BC372076B for ; Thu, 29 Oct 2020 09:42:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="PGVx1r1j"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="aBV/wJbd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726018AbgJ2Jm1 (ORCPT ); Thu, 29 Oct 2020 05:42:27 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:60264 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725929AbgJ2Jm1 (ORCPT ); Thu, 29 Oct 2020 05:42:27 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603964545; 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: in-reply-to:in-reply-to:references:references; bh=sNSYAEdWrJ1xkZ1r90fG2WzUbalLDSTU2+9QTihgyFI=; b=PGVx1r1jbStpvh5Yv8tpkkyWZtGyH454muOv0i7BA62QvIFOgpdk1CrFcxxzzOUGRgDgpf Q5Po/PjRWMFlbA4t9dhTvQ9zOZgoPZeWkPrbEtbtrNYBbfnQdlwHV7uah2rnRGBNJV+xLU iA5flm3Du5cd6VAWP5DHmPotHgTPYPbEp8AJ2uzVOBrxuKJhy9zejCPHeU2H6gssqQMyW3 QAlum3LoQkXbwHi3NhyQ3/DZbzMzVHHIbTMwZCswSwo0+YdBhI+4qhZjmZjJBvJTG237ev fX564zO8z68lKL/OoFAbfY3LHT3xt/gLHWsInZvaJAhq9AE5qsXVN3oyi5mw4Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603964545; 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: in-reply-to:in-reply-to:references:references; bh=sNSYAEdWrJ1xkZ1r90fG2WzUbalLDSTU2+9QTihgyFI=; b=aBV/wJbdlLBSgfOObd6bPytrxcV8EdAUNDqBf+iEcbVQRpxVZVhN5aHoKQhVpOkoztHb8g 000rQi4T1yIMJpBg== To: Heiner Kallweit , Jakub Kicinski Cc: Serge Belyshev , David Miller , Realtek linux nic maintainers , "netdev\@vger.kernel.org" , Eric Dumazet Subject: Re: [PATCH net] r8169: fix operation under forced interrupt threading In-Reply-To: References: <4d3ef84a-c812-5072-918a-22a6f6468310@gmail.com> <877drabmoq.fsf@depni.sinp.msu.ru> <20201028162929.5f250d12@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Date: Thu, 29 Oct 2020 10:42:25 +0100 Message-ID: <87y2jpe5by.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Oct 29 2020 at 09:42, Heiner Kallweit wrote: > On 29.10.2020 00:29, Jakub Kicinski wrote: >> Other handles may take spin_locks, which will sleep on RT. >> >> I guess we may need to switch away from the _irqoff() variant for >> drivers with IRQF_SHARED after all :( >> > Right. Unfortunately that's a large number of drivers, > e.g. pci_request_irq() sets IRQF_SHARED in general. IRQF_SHARED is not the problem. It only becomes a problem when the interrupt is actually shared which is only the case with the legacy PCI interrupt. MSI[X] is not affected at all. > But at least for now there doesn't seem to be a better way to deal > with the challenges imposed by forced threading and shared irqs. We still can do the static key trick, though it's admittedly hacky. Thanks, tglx