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 9B060C77B60 for ; Fri, 28 Apr 2023 07:31:14 +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=4Yy8vfVUjGxy/9dptrqHW5zjsBATwl0RY3tqNvkpcRw=; b=Odnj0fUN+S3VS5 1HSclzQPdMUsZroaACZFKvvoNdimNOQ0Z4xFsCm5WXEHHJz9Tr1yMQexotU5Ujij3KuSeo/sJmPY7 YWe7DKtK23QEXadTywVK7qEXkXP9rBGo1hefOK2rsfeka3s1XlF6LRtfO+b2VANNWqznK4QjSuP9M f+4u8rXxUFnG5jSuLs4pwVMxG5ixTb7SYGY0opzGS9jIvQVb5LJdigj/zP6eafnVWe62kkenFDTs+ bR8w4nEX1YsvuE7B/niPfyzpJHVYmIKS0rig52zoX3QiEBeK11F0cOYFsnTYroSmevS+2Vi4NgkVR WGKob8KDWlipHMdLeUSw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1psIYk-008Q73-2W; Fri, 28 Apr 2023 07:30:26 +0000 Received: from galois.linutronix.de ([2a0a:51c0:0:12e:550::1]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1psIYi-008Q5X-0A for linux-arm-kernel@lists.infradead.org; Fri, 28 Apr 2023 07:30:25 +0000 Date: Fri, 28 Apr 2023 09:30:16 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1682667018; 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: in-reply-to:in-reply-to:references:references; bh=tN4Is3StFqX6AUDx4ZBtDx5Nj+CllWKd/w/6il3hpyQ=; b=wqx15uW1RLL0CbZDoxYf5ZOThN2vIOeOq2pRMcep3M6h57EQBqS88obhqiWbiw88KViOj6 VA9ReGQc1QdyFAU9Gnu0TvgpcXr2nJoMzLhf67lUeuOCdPETj+rrDQlY595Qk93t3RsRo1 0LM7o3oy4fgT10huAydY8TmBduSwhpCojwWPdG+wd+jyUCw33XwLC//pPeuhftiFBfonp+ 22G7LfpOG5qABkwEuu2FEvauekWlNzGgu2IkD/WHuUCArEEroDybVQZHHhtotts8UvPDLO 1/NqGZlcelpcpp6qqvob0aYwbCWiMEAyuHcRpq5iz2+gWeLztgzNKXOppRs9dA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1682667018; 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: in-reply-to:in-reply-to:references:references; bh=tN4Is3StFqX6AUDx4ZBtDx5Nj+CllWKd/w/6il3hpyQ=; b=CY/OuaBlaNjH98AS9nB9bbKmsmkIbHNhue8djrmt85kZjYTw4OyGfX3OLYI3jiKqaWeXOn oEy3cUiN/9aAPTCA== From: Sebastian Andrzej Siewior To: Kurt Kanzenbach Cc: Jan Kiszka , Thomas Gleixner , "Bouska, Zdenek" , Will Deacon , Catalin Marinas , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "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: <20230428073016.YfrIGGoN@linutronix.de> References: <87pm7qxrg6.ffs@tglx> <19641ab0-ab6a-9af7-8c64-34030e187848@siemens.com> <871qk5782i.fsf@kurt> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <871qk5782i.fsf@kurt> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230428_003024_298496_99EF4FCA X-CRM114-Status: UNSURE ( 5.68 ) X-CRM114-Notice: Please train this message. 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 2023-04-27 15:45:09 [+0200], Kurt Kanzenbach wrote: > > Are we aware of other concrete case where it bites? Even with just > > "normal" contented spin_lock usage? > > Well, some years ago I've observed a similar problem with ARM64 > spinlocks, cpu_relax() and retry loops (in the futex code). It also > generated latency spikes up to 2-3ms. Back then, it was easily > reproducible using stress-ng --ptrace 4. That was fixed by https://patchwork.kernel.org/project/linux-arm-kernel/patch/1399528508-2806-1-git-send-email-arjun.kv@samsung.com if my memory serves me well. > Thanks, > Kurt Sebastian _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel