From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f199.google.com (mail-io0-f199.google.com [209.85.223.199]) by kanga.kvack.org (Postfix) with ESMTP id 481136B0038 for ; Fri, 17 Nov 2017 02:15:29 -0500 (EST) Received: by mail-io0-f199.google.com with SMTP id 9so458271ion.22 for ; Thu, 16 Nov 2017 23:15:29 -0800 (PST) Received: from szxga04-in.huawei.com (szxga04-in.huawei.com. [45.249.212.190]) by mx.google.com with ESMTPS id t65si557122iod.304.2017.11.16.23.15.26 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 16 Nov 2017 23:15:28 -0800 (PST) From: Yisheng Xie Subject: [PATCH] kmemcheck: add scheduling point to kmemleak_scan Date: Fri, 17 Nov 2017 15:03:56 +0800 Message-ID: <1510902236-4444-1-git-send-email-xieyisheng1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, catalin.marinas@arm.com, mhocko@kernel.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org kmemleak_scan will scan struct page for each node and it can be really large and resulting in a soft lockup. We have seen a soft lockup when do scan while compile kernel: [ 220.561051] watchdog: BUG: soft lockup - CPU#53 stuck for 22s! [bash:10287] [...] [ 220.753837] Call Trace: [ 220.756296] kmemleak_scan+0x21a/0x4c0 [ 220.760034] kmemleak_write+0x312/0x350 [ 220.763866] ? do_wp_page+0x147/0x4c0 [ 220.767521] full_proxy_write+0x5a/0xa0 [ 220.771351] __vfs_write+0x33/0x150 [ 220.774833] ? __inode_security_revalidate+0x4c/0x60 [ 220.779782] ? selinux_file_permission+0xda/0x130 [ 220.784479] ? _cond_resched+0x15/0x30 [ 220.788221] vfs_write+0xad/0x1a0 [ 220.791529] SyS_write+0x52/0xc0 [ 220.794758] do_syscall_64+0x61/0x1a0 [ 220.798411] entry_SYSCALL64_slow_path+0x25/0x25 Fix this by adding cond_resched every 1024 pages. Signed-off-by: Yisheng Xie --- mm/kmemleak.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index e4738d5..e9f2e86 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1523,6 +1523,8 @@ static void kmemleak_scan(void) if (page_count(page) == 0) continue; scan_block(page, page + 1, NULL); + if (!(pfn % 1024)) + cond_resched(); } } put_online_mems(); -- 1.7.12.4 -- 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