From patchwork Fri Jul 15 10:26:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 12918991 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 4B976CCA47F for ; Fri, 15 Jul 2022 10:27:49 +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:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=+hOHbOFdwVTqI35uFY3nPL5OsAbIdJMrV5KI0D6YZQs=; b=3PGjCeYtZ9zF6M HgFCf9ER9oiU4dsqpSwGeayazsqO6HsxqCBuQPTwq6P4v/TmqaD+6abxikVhh6Amn/3ifXnRn9pXy 6uW3HTVYQAVq7qei8LpUnFIvxZpXZ/WlHw7kJW3bBSfyQi/wBev5DjBVnNwd8nUBfu6LaqTVHTCFA V5eIpgnPL3SPKVCHMk8sLvUMDJXH4XJqIEuDF5GwQPU70zK5jLAiqOzvv6rcuIYq2uzccBdqpS7aG UZVwSWqIhHsruKBSQkO6IHXog+XevMXSy2qB7pgBWaomqmkWO/paCAZFnfKbk7ZrmpvIB54D8h0Rm QxgKWmgJ7AEmFCUtdphw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oCIWq-006Kni-55; Fri, 15 Jul 2022 10:26:36 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oCIWm-006Kkz-Na; Fri, 15 Jul 2022 10:26:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 942BD1474; Fri, 15 Jul 2022 03:26:18 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C99223F792; Fri, 15 Jul 2022 03:26:16 -0700 (PDT) From: Sudeep Holla To: linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Conor Dooley Cc: Sudeep Holla , Vincent Guittot , Dietmar Eggemann , Ionela Voinescu , Pierre Gondois , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org Subject: [PATCH -next v2 1/2] cacheinfo: Use atomic allocation for percpu cache attributes Date: Fri, 15 Jul 2022 11:26:08 +0100 Message-Id: <20220715102609.2160689-1-sudeep.holla@arm.com> X-Mailer: git-send-email 2.37.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220715_032632_838076_FFA5CFDE X-CRM114-Status: GOOD ( 10.21 ) 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 couple of architectures like RISC-V and ARM64, we need to detect cache attribues quite early during the boot when the secondary CPUs start. So we will call detect_cache_attributes in the atomic context and since use of normal allocation can sleep, we will end up getting "sleeping in the atomic context" bug splat. In order avoid that, move the allocation to use atomic version in preparation to move the actual detection of cache attributes in the CPU hotplug path which is atomic. Cc: Ionela Voinescu Tested-by: Conor Dooley Signed-off-by: Sudeep Holla Acked-by: Conor Dooley --- drivers/base/cacheinfo.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Hi Greg, Can you apply these couple of patches directly if and when you are happy with them ? Regards, Sudeep v1->v2: This was added in v2 -- 2.37.1 diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 65d566ff24c4..4b5cd08c5a65 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -356,7 +356,7 @@ int detect_cache_attributes(unsigned int cpu) return -ENOENT; per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), - sizeof(struct cacheinfo), GFP_KERNEL); + sizeof(struct cacheinfo), GFP_ATOMIC); if (per_cpu_cacheinfo(cpu) == NULL) { cache_leaves(cpu) = 0; return -ENOMEM; From patchwork Fri Jul 15 10:26:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 12918992 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 092EFCCA47C for ; Fri, 15 Jul 2022 10:27:48 +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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UWkxjdipfqhd8NtMZOJA/xxPW5sLffUGv8OK8SfvtKc=; b=OHSftGZcpOhSpR eAMIGEX/lf9bV6TL5oG9DCPMDGgjSHMHGCePAJu+uA17D7LaCb6NzBmzhwyqrc+OHUch8Lwnk8uKG RmjwFKDfJQtp9IlNEgXlrnZBfabrdiKQvu+QnT9T0erBA/QktYmvdwHZ4b78tRibJCq/Q8RJhN9Hl vwCFHGKZPh1p4xtQb8sudzb3QY+sogY8Kfi4i/v2jfhtRZIO2lWrDYhZFnieOZtPlyLJWmuwtnkLU ibdl3SJq44C+6YJ0VAuYXot19ddyN1dR4cbD7blZqZUqKq643EsneoOF8XMbxyKFidnwXvTvpSE12 1WCehybix98BtiNPzTpg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oCIWy-006KqD-1E; Fri, 15 Jul 2022 10:26:44 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oCIWm-006KmE-Nb; Fri, 15 Jul 2022 10:26:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DB4281D13; Fri, 15 Jul 2022 03:26:21 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1E0403F792; Fri, 15 Jul 2022 03:26:20 -0700 (PDT) From: Sudeep Holla To: linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Conor Dooley Cc: Sudeep Holla , Vincent Guittot , Dietmar Eggemann , Ionela Voinescu , Pierre Gondois , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org Subject: [PATCH -next v2 2/2] arch_topology: Fix cache attributes detection in the CPU hotplug path Date: Fri, 15 Jul 2022 11:26:09 +0100 Message-Id: <20220715102609.2160689-2-sudeep.holla@arm.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220715102609.2160689-1-sudeep.holla@arm.com> References: <20220715102609.2160689-1-sudeep.holla@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220715_032632_838518_AD40FFDE X-CRM114-Status: GOOD ( 13.15 ) 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 init_cpu_topology() is called only once at the boot and all the cache attributes are detected early for all the possible CPUs. However when the CPUs are hotplugged out, the cacheinfo gets removed. While the attributes are added back when the CPUs are hotplugged back in as part of CPU hotplug state machine, it ends up called quite late after the update_siblings_masks() are called in the secondary_start_kernel() resulting in wrong llc_sibling_masks. Move the call to detect_cache_attributes() inside update_siblings_masks() to ensure the cacheinfo is updated before the LLC sibling masks are updated. This will fix the incorrect LLC sibling masks generated when the CPUs are hotplugged out and hotplugged back in again. Reported-by: Ionela Voinescu Tested-by: Ionela Voinescu Reviewed-by: Conor Dooley Reviewed-by: Ionela Voinescu Signed-off-by: Sudeep Holla Tested-by: Geert Uytterhoeven --- drivers/base/arch_topology.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) v1->v2: - No change in this patch, but 1/2 was added to fix possible bug "sleeping in the atomic context" with this patch. - Added all the received tags -- 2.37.1 diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 441e14ac33a4..0424b59b695e 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -732,7 +732,11 @@ const struct cpumask *cpu_clustergroup_mask(int cpu) void update_siblings_masks(unsigned int cpuid) { struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid]; - int cpu; + int cpu, ret; + + ret = detect_cache_attributes(cpuid); + if (ret) + pr_info("Early cacheinfo failed, ret = %d\n", ret); /* update core and thread sibling masks */ for_each_online_cpu(cpu) { @@ -821,7 +825,7 @@ __weak int __init parse_acpi_topology(void) #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV) void __init init_cpu_topology(void) { - int ret, cpu; + int ret; reset_cpu_topology(); ret = parse_acpi_topology(); @@ -836,13 +840,5 @@ void __init init_cpu_topology(void) reset_cpu_topology(); return; } - - for_each_possible_cpu(cpu) { - ret = detect_cache_attributes(cpu); - if (ret) { - pr_info("Early cacheinfo failed, ret = %d\n", ret); - break; - } - } } #endif