From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1215D18A6A3; Wed, 31 Jul 2024 08:25:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722414304; cv=none; b=DAx+ugOPOImPXsInzeZqBi6uZkioWYoY+qOzZ4C+3zUlOGTDYD8lpp+STzfNsFHJ1pT6YweI9ywRL66ybMUkdcHh10qj4TdoqQTMHPqywqoQB2f1PAJ/jW4gDUvS4qEL4TXVNpF9uwicXmM+QytqNdapwIe2OZ07rGUzsgKgHOU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722414304; c=relaxed/simple; bh=V/qMid1eZAZ9KqR4unGjgGs1o2BzZRAEjRLlRpm8Vdg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XQZysK/hiTWK/v4qyLBgmxpR7UTuycJ36DNuHoRxem6cpijJ3fkOqiQVF3iCHmyza7+l07CGdLLk6PFNWJLFbqzyDczNq9uRbCSrvRJTzUhUlb4F8iM1gGgYRykHbYbQP2uK8YSRMnUFudGtLzHzXdWSkAJLh5EOBKVgBRrUqDA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=qPifwyiA; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="qPifwyiA" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=9Ohyf01z+RQdbQQcz4+PP/EvJqHgnb9g8adgwYo0As8=; b=qPifwyiAX5xb8gnHPkVc5vS3zC RT5FqN29h0hS/WprOebZI85qTmsYpZaejB9WhdNcrwsxSdYSJI0QSgn2INPKdKdll53n/D1YAhdp8 gwB2L4KmKY1xgxqUw+DJ2n5FVvb+qSSkZFLMGPWkQFvae7FOhuJ0HUyIkjxge3H449D1fgYrLkdO4 XleptULGrZfO7P0MubCgGChxybTVRcZosZ38IqC1HpZvA4NJ/mZ22b0cWuwO02B1KRbG8Rojx/M61 rXNVMvDS9pXywgSmJRZoVVoyGQuVvbtasj9zj2WHEi8PNcwwiyrVkT/9QLe5vv86DSBxfEcuziJz0 ZDG1+22g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:60238) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1sZ4dO-0008GX-0p; Wed, 31 Jul 2024 09:24:34 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1sZ4dM-00063s-9V; Wed, 31 Jul 2024 09:24:32 +0100 Date: Wed, 31 Jul 2024 09:24:32 +0100 From: "Russell King (Oracle)" To: Jinjie Ruan Cc: arnd@arndb.de, afd@ti.com, akpm@linux-foundation.org, linus.walleij@linaro.org, eric.devolder@oracle.com, robh@kernel.org, vincent.whitchurch@axis.com, bhe@redhat.com, nico@fluxnic.net, ardb@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH] ARM: support PREEMPT_DYNAMIC Message-ID: References: <20240620090028.729373-1-ruanjinjie@huawei.com> <79a3de7c-21da-12ce-8372-9c9029c237ac@huawei.com> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <79a3de7c-21da-12ce-8372-9c9029c237ac@huawei.com> Sender: Russell King (Oracle) On Wed, Jul 31, 2024 at 10:07:53AM +0800, Jinjie Ruan wrote: > > #ifdef CONFIG_PREEMPTION > > +#ifdef CONFIG_PREEMPT_DYNAMIC > > + bl need_irq_preemption > > + cmp r0, #0 > > + beq 2f > > +#endif Depending on the interrupt rate, this can be regarded as a fast path, it would be nice if we could find a way to use static branches in assembly code. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!