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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B593C433F5 for ; Wed, 29 Sep 2021 07:24:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2885961042 for ; Wed, 29 Sep 2021 07:24:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244634AbhI2H0S (ORCPT ); Wed, 29 Sep 2021 03:26:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:37344 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244620AbhI2H0R (ORCPT ); Wed, 29 Sep 2021 03:26:17 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D11D46137A; Wed, 29 Sep 2021 07:24:36 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mVTxC-00Dfkl-QL; Wed, 29 Sep 2021 08:24:34 +0100 Date: Wed, 29 Sep 2021 08:24:34 +0100 Message-ID: <87lf3fu9n1.wl-maz@kernel.org> From: Marc Zyngier To: Pingfan Liu Cc: linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Mark Rutland , Joey Gouly , Sami Tolvanen , Julien Thierry , Thomas Gleixner , Yuichi Ito , linux-kernel@vger.kernel.org Subject: Re: [PATCHv2 5/5] irqchip/GICv3: make reschedule-ipi light weight In-Reply-To: <20210924132837.45994-6-kernelfans@gmail.com> References: <20210924132837.45994-1-kernelfans@gmail.com> <20210924132837.45994-6-kernelfans@gmail.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kernelfans@gmail.com, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, joey.gouly@arm.com, samitolvanen@google.com, julien.thierry@arm.com, tglx@linutronix.de, ito-yuichi@fujitsu.com, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 24 Sep 2021 14:28:37 +0100, Pingfan Liu wrote: > > To achieve the light weight as > DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_reschedule_ipi) on x86, it had > better treat irqnr differently at the frontend. And let IPI_RESCHEDULE > call __irq_enter_raw() instead of irq_enter_rcu(). > > Signed-off-by: Pingfan Liu > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Mark Rutland > Cc: Marc Zyngier > Cc: Joey Gouly > Cc: Sami Tolvanen > Cc: Julien Thierry > Cc: Thomas Gleixner > Cc: Yuichi Ito > Cc: linux-kernel@vger.kernel.org > To: linux-arm-kernel@lists.infradead.org > --- > drivers/irqchip/irq-gic-v3.c | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c > index 906538fa8771..593d4539a209 100644 > --- a/drivers/irqchip/irq-gic-v3.c > +++ b/drivers/irqchip/irq-gic-v3.c > @@ -709,6 +709,9 @@ static void gic_handle_nmi(struct pt_regs *regs) > gic_deactivate_unhandled(irqnr); > } > > +/* RESCHEDULE IPI hwirq nr is 0, and the only raw one */ > +static unsigned long raw_interrupt_mask = 1; I'm afraid you have the wrong end of the stick. This isn't a GIC property. This is an architecture decision, and only the architecture can expose what they want. M. -- Without deviation from the norm, progress is not possible.