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 7E55AC77B73 for ; Thu, 27 Apr 2023 10:07:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=rbiLd36b8CAjD3oBWcjKeWjDfEhc32yHvr6+DpIh0Uo=; b=ybNp5Oh2UBKvT/ 1lKOJpde55p0OwFc+XVGy/k4EoFQDhSR/ZhyG5R04myKQgIRXO0EZozUaGNoCGa+QGfDeLp8iO1vL vdgNFrbGm3qbf1dfNR9RxPE4yanhnzq8nwjALksqMQ8F434fscZpgno0qyJEL1BZOOueeFD8AEhdA WlX79XgtkM2/Dj6tNLLaoI57CVR3U66McXIIjESIQ2D5nu5mdVUJ7i7c+CudaEv+pKdP+T7JHSn2T 0mZuq84OQE6V9oSJ6AcFvL1pdTiUxvnpVfn7W+/ogaVDjIUV8Xp449aE2EOAwKfJuLWPGy3+d0zSE +unvUSbS4dM+9RwuqZ5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pryWr-0066L7-0g; Thu, 27 Apr 2023 10:07:09 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pryWn-0066Js-0O for linux-arm-kernel@lists.infradead.org; Thu, 27 Apr 2023 10:07:06 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1000C60F02; Thu, 27 Apr 2023 10:07:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDF70C433EF; Thu, 27 Apr 2023 10:07:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1682590022; bh=NpPUxdiGmbPhMzPhGolYoqA+iiu2qAbTIUmG3IlvkBg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uopaMlnxAadrlJeOvUyXERVtGXrAzEIpeMldv/tk06iMcNE7F3/hWfRj+Ca/EUtXb YdUsi6lCe8viviR8eAZm5/Mnv2f3WZ1wmXnrniXiesePc/22nBQmZe6vdlGPiPjsH1 jZssnpP9l4KgpFNHBQeeMoM6ebmwHpWYxqoDMsDOgYwByzaBkJALj6i+dGbH2Inby6 pgWeOqazPR8GxI6JJUoI64n6zcMvKDj9OajMirX+Bb3VrtSvPa5zWdkv1PY/PKjulx 7nNWEq7qTf2PJpukuqRlk21euEUCxN1l/ctfm6C/5c2AhQJqLMSS6gvez1G09U6EMk j8aceljwHzt7A== Date: Thu, 27 Apr 2023 11:06:57 +0100 From: Will Deacon To: "Bouska, Zdenek" Cc: Thomas Gleixner , Catalin Marinas , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "Kiszka, Jan" , "linux-rt-users@vger.kernel.org" , Nishanth Menon , Puranjay Mohan Subject: Re: Unfair qspinlocks on ARM64 without LSE atomics => 3ms delay in interrupt handling Message-ID: <20230427100656.GA10855@willie-the-truck> References: <87pm7qxrg6.ffs@tglx> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230427_030705_220703_60878576 X-CRM114-Status: GOOD ( 17.59 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Apr 27, 2023 at 09:38:59AM +0000, Bouska, Zdenek wrote: > > Why is this interrupt handling specific? Just because it's the place > > where you observed it? > Yes. > > > So if that helps, then this needs to be addressed globaly and not with > > some crude hack in the interrupt handling code. > I just wrote, what helps for me. I didn't mean it as a proposal for merge. > Sorry for confusion. > > I tried using Will's cpu_relax() implementation [1] everywhere but I was not > successful with that yet. ARM64's VDSO makes it complicating and even > if I left original cpu_relax() just in VDSO, Linux did not boot for me. It definitely seemed to work when I posted it all those years ago, but I'm not surprised if it needs some TLC to revive it on more recent kernels. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel