From patchwork Thu Jan 2 22:07:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 234616 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE359C3276D for ; Thu, 2 Jan 2020 22:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4CDC20863 for ; Thu, 2 Jan 2020 22:45:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578005142; bh=GPaWdBquP7lqPDeAbE7TakV5GZ9kyvRxN5I/6f0ImS8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XUpGzdQMDhZCsWo9B67r/uwMyTcQn19/nZTL0IoFTfYf0HGAIBvtNZTs4teZUJ/If yJUn9/q3I2md3nNe+zK1RLfKHvdv+KfswCNNCJmp8PQoo0eEpp/RX1O6mYXe9DrhIi RB8fbnTcNXoAEWwWuq0l9eaUovUrdTYP52tIUCqg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729862AbgABWbt (ORCPT ); Thu, 2 Jan 2020 17:31:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:37316 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730325AbgABWbr (ORCPT ); Thu, 2 Jan 2020 17:31:47 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F226D21D7D; Thu, 2 Jan 2020 22:31:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004306; bh=GPaWdBquP7lqPDeAbE7TakV5GZ9kyvRxN5I/6f0ImS8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=niGdwKBfzlt2v90xozIvv4dY9TpBdK9jYshtUeN00KAk0mAbnJiE2kSE4ltcOeJhS a5xHHVbIoHt8TPvYQQcFnhmFsSG+5035sMIHg3j0FVvsh3sq0Mj44Ia2BmYJvIJrk0 yK85sUhRNEZSHj/nRSt7ijEEJNzsqtpsFkvSfGeE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Aneesh Kumar K.V" , Michael Ellerman , Sasha Levin Subject: [PATCH 4.9 123/171] powerpc/book3s64/hash: Add cond_resched to avoid soft lockup warning Date: Thu, 2 Jan 2020 23:07:34 +0100 Message-Id: <20200102220604.101673134@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102220546.960200039@linuxfoundation.org> References: <20200102220546.960200039@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Aneesh Kumar K.V [ Upstream commit 16f6b67cf03cb43db7104acb2ca877bdc2606c92 ] With large memory (8TB and more) hotplug, we can get soft lockup warnings as below. These were caused by a long loop without any explicit cond_resched which is a problem for !PREEMPT kernels. Avoid this using cond_resched() while inserting hash page table entries. We already do similar cond_resched() in __add_pages(), see commit f64ac5e6e306 ("mm, memory_hotplug: add scheduling point to __add_pages"). rcu: 3-....: (24002 ticks this GP) idle=13e/1/0x4000000000000002 softirq=722/722 fqs=12001 (t=24003 jiffies g=4285 q=2002) NMI backtrace for cpu 3 CPU: 3 PID: 3870 Comm: ndctl Not tainted 5.3.0-197.18-default+ #2 Call Trace: dump_stack+0xb0/0xf4 (unreliable) nmi_cpu_backtrace+0x124/0x130 nmi_trigger_cpumask_backtrace+0x1ac/0x1f0 arch_trigger_cpumask_backtrace+0x28/0x3c rcu_dump_cpu_stacks+0xf8/0x154 rcu_sched_clock_irq+0x878/0xb40 update_process_times+0x48/0x90 tick_sched_handle.isra.16+0x4c/0x80 tick_sched_timer+0x68/0xe0 __hrtimer_run_queues+0x180/0x430 hrtimer_interrupt+0x110/0x300 timer_interrupt+0x108/0x2f0 decrementer_common+0x114/0x120 --- interrupt: 901 at arch_add_memory+0xc0/0x130 LR = arch_add_memory+0x74/0x130 memremap_pages+0x494/0x650 devm_memremap_pages+0x3c/0xa0 pmem_attach_disk+0x188/0x750 nvdimm_bus_probe+0xac/0x2c0 really_probe+0x148/0x570 driver_probe_device+0x19c/0x1d0 device_driver_attach+0xcc/0x100 bind_store+0x134/0x1c0 drv_attr_store+0x44/0x60 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1a0/0x270 __vfs_write+0x3c/0x70 vfs_write+0xd0/0x260 ksys_write+0xdc/0x130 system_call+0x5c/0x68 Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191001084656.31277-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/mm/hash_utils_64.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index de1d8cdd2991..2dc1fc445f35 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -300,6 +300,7 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend, if (ret < 0) break; + cond_resched(); #ifdef CONFIG_DEBUG_PAGEALLOC if (debug_pagealloc_enabled() && (paddr >> PAGE_SHIFT) < linear_map_hash_count)