From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f198.google.com (mail-ot0-f198.google.com [74.125.82.198]) by kanga.kvack.org (Postfix) with ESMTP id 33AFC6B0279 for ; Sun, 11 Jun 2017 20:47:55 -0400 (EDT) Received: by mail-ot0-f198.google.com with SMTP id 36so31706443otv.7 for ; Sun, 11 Jun 2017 17:47:55 -0700 (PDT) Received: from smtp.codeaurora.org (smtp.codeaurora.org. [198.145.29.96]) by mx.google.com with ESMTPS id u132si2624422oia.239.2017.06.11.17.47.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 11 Jun 2017 17:47:53 -0700 (PDT) From: Sahitya Tummala Subject: [PATCH] mm/list_lru.c: use cond_resched_lock() for nlru->lock Date: Mon, 12 Jun 2017 06:17:20 +0530 Message-Id: <1497228440-10349-1-git-send-email-stummala@codeaurora.org> Sender: owner-linux-mm@kvack.org List-ID: To: Alexander Polakov , Andrew Morton , Vladimir Davydov , Jan Kara , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Sahitya Tummala __list_lru_walk_one() can hold the spin lock for longer duration if there are more number of entries to be isolated. This results in "BUG: spinlock lockup suspected" in the below path - [] spin_bug+0x90 [] do_raw_spin_lock+0xfc [] _raw_spin_lock+0x28 [] list_lru_add+0x28 [] dput+0x1c8 [] path_put+0x20 [] terminate_walk+0x3c [] path_lookupat+0x100 [] filename_lookup+0x6c [] user_path_at_empty+0x54 [] SyS_faccessat+0xd0 [] el0_svc_naked+0x24 This nlru->lock has been acquired by another CPU in this path - [] d_lru_shrink_move+0x34 [] dentry_lru_isolate_shrink+0x48 [] __list_lru_walk_one.isra.10+0x94 [] list_lru_walk_node+0x40 [] shrink_dcache_sb+0x60 [] do_remount_sb+0xbc [] do_emergency_remount+0xb0 [] process_one_work+0x228 [] worker_thread+0x2e0 [] kthread+0xf4 [] ret_from_fork+0x10 Link: http://marc.info/?t=149511514800002&r=1&w=2 Fix-suggested-by: Jan kara Signed-off-by: Sahitya Tummala --- mm/list_lru.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/list_lru.c b/mm/list_lru.c index 5d8dffd..1af0709 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -249,6 +249,8 @@ restart: default: BUG(); } + if (cond_resched_lock(&nlru->lock)) + goto restart; } spin_unlock(&nlru->lock); -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org