From patchwork Wed May 10 17:12:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13237110 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 299A6C77B7C for ; Wed, 10 May 2023 17:12:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236395AbjEJRMu (ORCPT ); Wed, 10 May 2023 13:12:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230440AbjEJRMr (ORCPT ); Wed, 10 May 2023 13:12:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBB5E55AD; Wed, 10 May 2023 10:12:41 -0700 (PDT) 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 6BA9664A32; Wed, 10 May 2023 17:12:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7D3EC433A0; Wed, 10 May 2023 17:12:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683738760; bh=KDLz2XZ/U61uBOSzISq5Lmmyrsw5rPfsdBYT/yaU1gs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kH2H8Nwzm84ddIvkA4D8C9Uo9xeEuzeudQxT16AV+LHp7D+4rWV9ORCvdVjzzlIxD 4EAU3MzApfhHoow7hEvlePyhVbv0OeLcrO1TjT6C1DltuNBxUd0WVjNJTw6ZY9j97F hVTOfKJlqD99jV+gmzDgvUJN7LS8MdBpRnBBKPBrUp2GuaO53Eb6x91TnzdSVsPGck 4DbVhhmHJoHnPr4yO562ldfMcPuFT2xGTmdEk35s3HnbeKo94MUcfsrZ6jbkxbqAxE Rbui9GV7ISb8wviqseT/2pMpBAzF8VYZnx2ebknwWjz3Wj4x3GUueqzhnFY1Kv6j5r yBjaPgNySlVUw== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 5D937CE127D; Wed, 10 May 2023 10:12:40 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, Qiuxu Zhuo , Davidlohr Bueso , Joel Fernandes , "Paul E . McKenney" Subject: [PATCH rcu 4/6] rcu/rcuscale: Stop kfree_scale_thread thread(s) after unloading rcuscale Date: Wed, 10 May 2023 10:12:36 -0700 Message-Id: <20230510171238.2189921-4-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <7ffd4a5d-61e9-4b4c-a312-a85bcde08c39@paulmck-laptop> References: <7ffd4a5d-61e9-4b4c-a312-a85bcde08c39@paulmck-laptop> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Qiuxu Zhuo Running the 'kfree_rcu_test' test case [1] results in a splat [2]. The root cause is the kfree_scale_thread thread(s) continue running after unloading the rcuscale module. This commit fixes that isue by invoking kfree_scale_cleanup() from rcu_scale_cleanup() when removing the rcuscale module. [1] modprobe rcuscale kfree_rcu_test=1 // After some time rmmod rcuscale rmmod torture [2] BUG: unable to handle page fault for address: ffffffffc0601a87 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 11de4f067 P4D 11de4f067 PUD 11de51067 PMD 112f4d067 PTE 0 Oops: 0010 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 1798 Comm: kfree_scale_thr Not tainted 6.3.0-rc1-rcu+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:0xffffffffc0601a87 Code: Unable to access opcode bytes at 0xffffffffc0601a5d. RSP: 0018:ffffb25bc2e57e18 EFLAGS: 00010297 RAX: 0000000000000000 RBX: ffffffffc061f0b6 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff962fd0de RDI: ffffffff962fd0de RBP: ffffb25bc2e57ea8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 000000000000000a R15: 00000000001c1dbe FS: 0000000000000000(0000) GS:ffff921fa2200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffc0601a5d CR3: 000000011de4c006 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? kvfree_call_rcu+0xf0/0x3a0 ? kthread+0xf3/0x120 ? kthread_complete_and_exit+0x20/0x20 ? ret_from_fork+0x1f/0x30 Modules linked in: rfkill sunrpc ... [last unloaded: torture] CR2: ffffffffc0601a87 ---[ end trace 0000000000000000 ]--- Fixes: e6e78b004fa7 ("rcuperf: Add kfree_rcu() performance Tests") Reviewed-by: Davidlohr Bueso Reviewed-by: Joel Fernandes (Google) Signed-off-by: Qiuxu Zhuo Signed-off-by: Paul E. McKenney --- kernel/rcu/rcuscale.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c index 7e8965b0827a..d1221731c7cf 100644 --- a/kernel/rcu/rcuscale.c +++ b/kernel/rcu/rcuscale.c @@ -797,6 +797,11 @@ rcu_scale_cleanup(void) if (gp_exp && gp_async) SCALEOUT_ERRSTRING("No expedited async GPs, so went with async!"); + if (kfree_rcu_test) { + kfree_scale_cleanup(); + return; + } + if (torture_cleanup_begin()) return; if (!cur_ops) {