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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4975BCCF9F1 for ; Thu, 30 Oct 2025 10:38:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id: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-Owner; bh=lEy1pzlBxEDKuz9VSbjEr50+/lWvYrPAgZ9M9/u5gJc=; b=QlZA+fmcYi/XiyPiqJI581bbKt kswKY21SP8qpD/uyAV+y5OVQjbWWLDgoZHmmY8WIz0ozQ7G0snv5Q0l3EaQs4FhkPv/uk8PoFRA/2 xW9ShlMq9DZiSxGp8EoT1DpUlqnn/6UeO4JxXYa+PdJfNawCEHP3XCfusNio0NXym6bFxT1yOh5X6 uYdtA6EVxd29JZl7xNFhu6JURxpQS/9uRDIzkgkpDwYWraESFQJwY4vI+6yUO+3bYZ/mTSZNlr8v7 pn9yC66fJjexWmnZDcxDKCS0/PC0FGCffjDY5c+mUgxd2DrctFXqN+zHbo6s9NDnIKPh/0SOukY/W 4XmoBziw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vEQ2s-000000040OE-19sF; Thu, 30 Oct 2025 10:38:18 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vEQ2q-000000040Nl-0iu5 for linux-arm-kernel@lists.infradead.org; Thu, 30 Oct 2025 10:38:17 +0000 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=lEy1pzlBxEDKuz9VSbjEr50+/lWvYrPAgZ9M9/u5gJc=; b=K2ocgODhGfZUa+rFjoxN6HdHrC fIemRICg6B7cQX4qQQJxPD++XA+tm3szSlSA1QAolcn2cIG9onf3/Tpx7Zce/5ugAQcw19A7InhpZ 0DWCbe2BuiIjfF04Z1ptn3vATb5T1mOU/Mt0nBMkDhFFhIs94Nobiu0ct+OojsRS8N3R2zWe1OgUb GMkowlp7mIDcN64hWfKrXWdEDA8c9M02A/Ag8rUHt2N2BM54zIm8EtpjmFhkzzYjy3HrHbgP6S/Bk vVdXzIyXZczWSiletA1uhr0yuo+XXlJSWzKTvrc5PIP2tB6GbIXe2lGhVeRh2TBajV7ZDNo8t0hSy r5Ms6uXA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:48466) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1vEQ2m-000000005Yv-0in2; Thu, 30 Oct 2025 10:38:12 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1vEQ2k-000000008Nf-33Er; Thu, 30 Oct 2025 10:38:10 +0000 Date: Thu, 30 Oct 2025 10:38:10 +0000 From: "Russell King (Oracle)" To: Sebastian Andrzej Siewior Cc: Xie Yuanbin , arnd@arndb.de, linux-arm-kernel@lists.infradead.org, linux-rt-devel@lists.linux.dev, tglx@linutronix.de Subject: Re: [PATCH 4/5] ARM: Disable jump-label on PREEMPT_RT. Message-ID: References: <20251030072339.63vdFNo3@linutronix.de> <20251030074507.33863-1-xieyuanbin1@huawei.com> <20251030075558.sUBj8_6U@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251030075558.sUBj8_6U@linutronix.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251030_033816_207103_7ACBE972 X-CRM114-Status: GOOD ( 10.45 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Oct 30, 2025 at 08:55:58AM +0100, Sebastian Andrzej Siewior wrote: > Arm64 and X86 replaced the stop_machine() logic with something else that > does not affect latency in that magnitude. If Arm could something > similar then fine but until then I don't see a way around it. "If Arm could". For 32-bit, Arm Ltd isn't going to do anything, it's old as far as they're concerned. It's up to those participating in the kernel community to maintain and look after the code. Thus, if there is a desire for something other than stop_machine() then it is up to those who care about the issue to do something about it, rather than expecting someone else to do something for them. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!