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=-5.8 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 509DBC433B4 for ; Tue, 13 Apr 2021 20:24:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 187DF613C7 for ; Tue, 13 Apr 2021 20:24:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232288AbhDMUYz (ORCPT ); Tue, 13 Apr 2021 16:24:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232014AbhDMUYx (ORCPT ); Tue, 13 Apr 2021 16:24:53 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C11AEC061574 for ; Tue, 13 Apr 2021 13:24:31 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1618345469; 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=puB3GJUkP344AQ6MQj+RwIsjsnRpeaZ2ypqnxOsH/TA=; b=izjZVUEjSvnlr5xGZ7zDind+IdlrIZ+35sp/DCrQt58QdytCKsviH8urj+ukR5N7u8Pg3l 5AlQWLMKkeL0adLwN9ZCbI2HU6/jTRFqPF5x0mDVanPkkbP4sSQBwvnNJ+sNp/sWR3Ka3b TO+IBO1BfEkw1pinR4aWGIw+eLLJWRvvkEsOlpudRxNjHdy7aQlVHYPTPcDIKfRWIhG/X7 yvk5XTF/QErq6fTDoAbKmjpaMrvpjToGTYqR2Yn6YsqcsY5rb3YfiCTQomW+i4J2pSnUwR QwTfx/oKRex8/tET3y+4ze+ZLO0+dCH+h47wN6GSUhv6PPntLAfdp1pcEIlb1A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1618345469; 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=puB3GJUkP344AQ6MQj+RwIsjsnRpeaZ2ypqnxOsH/TA=; b=AStz3/WTa1zPeUMPPhSSiyO8mL/M52jaxyy0avpXn7bKAzksr9sZdNUhvsF4nny4B0JaPU HkLItS7PoN+fegAg== To: =?utf-8?Q?C=C3=A9dric?= Le Goater , Nicholas Piggin Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] genirq: reduce irqdebug bouncing cachelines In-Reply-To: References: <20210402132037.574661-1-npiggin@gmail.com> <87im4u2vxx.ffs@nanos.tec.linutronix.de> <2dae4501-6f01-1b32-4b69-1dfc94c93425@kaod.org> <87wnt71xmm.ffs@nanos.tec.linutronix.de> Date: Tue, 13 Apr 2021 22:24:28 +0200 Message-ID: <87tuoax79f.ffs@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 13 2021 at 14:16, C=C3=A9dric Le Goater wrote: >>> We could test irq_settings_no_debug() directly under handle_nested_irq(= )=20 >>> and handle_irq_event_percpu() to avoid calling note_interrupt(), just=20 >>> like we do for noirqdebug. >>=20 >> We can do that, but then we should not just make it: >>=20 >> if (!irqnodebug && !irq_settings_no_debug(desc)) >> note_interrupt(...); >>=20 >> Instead have only one condition: >>=20 >> if (!irq_settings_no_debug(desc)) >> note_interrupt(...); >>=20 >> See the uncompiled delta patch below. > > I merged this second part with the first and gave IRQF_NO_DEBUG a try=20 > on P8 and P9 systems and all looked fine. I should send both patches=20 > after IRQF_NO_AUTOEN is merged in mainline.=20=20=20=20=20 Does having that NODEBUG flag set on the IPI irqs make a measurable difference or is it just too small to matter? Thanks, tglx