From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Slaby Subject: udev loops eating 100 % CPU [mmotm 2010-05-21-16-05] Date: Tue, 25 May 2010 14:12:39 +0200 Message-ID: <4BFBBEB7.4070107@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Cc: Al Viro , Kay Sievers , Linux kernel mailing list , linux-fsdevel@vger.kernel.org, Andrew Morton To: Eric Paris Return-path: Received: from fg-out-1718.google.com ([72.14.220.152]:39008 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755010Ab0EYMMo (ORCPT ); Tue, 25 May 2010 08:12:44 -0400 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hi, >>From next/master: commit a7cf4145bb86aaf85d4d4d29a69b50b688e2e49d Author: Eric Paris Date: Fri May 14 11:44:10 2010 -0400 anon_inode: set S_IFREG on the anon_inode anon_inode_mkinode() sets inode->i_mode = S_IRUSR | S_IWUSR; This means that (inode->i_mode & S_IFMT) == 0. This trips up some SELinux code that needs to determine if a given inode is a regular file, a directory, etc. The easiest solution is to just make sure that the anon_inode also sets S_IFREG. Signed-off-by: Eric Paris Signed-off-by: Al Viro causes my udev and psi both eating 100 % CPU. When I revert that on the top of mmotm 2010-05-21-16-05, the problem disappears. These are red-numbered lines from perf: 13.96% udevd [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore 10.22% udevd [kernel.kallsyms] [k] signalfd_poll 7.82% udevd [kernel.kallsyms] [k] system_call_after_swapgs 6.33% udevd [kernel.kallsyms] [k] do_sys_poll 5.43% udevd udevd [.] 0x0000000000dc72 It loops with this strace: ioctl(7, FIONREAD, [0]) = 0 poll([{fd=4, events=POLLIN}, {fd=6, events=POLLIN}, {fd=7, events=POLLIN}, {fd=8, events=POLLIN}, {fd=9, events=POLLIN}], 5, 3000) = 1 ([{fd=7, revents=POLLIN}]) where /proc/.../fd is: lrwx------ 1 root root 64 May 25 14:06 0 -> /dev/null lrwx------ 1 root root 64 May 25 14:06 1 -> /dev/null lrwx------ 1 root root 64 May 25 14:06 10 -> socket:[1676] lrwx------ 1 root root 64 May 25 14:06 2 -> /dev/null lrwx------ 1 root root 64 May 25 14:06 3 -> /dev/.udev/queue.bin lrwx------ 1 root root 64 May 25 14:06 4 -> socket:[1673] l-wx------ 1 root root 64 May 25 14:06 5 -> /dev/blog lrwx------ 1 root root 64 May 25 14:06 6 -> socket:[1674] lr-x------ 1 root root 64 May 25 14:06 7 -> anon_inode:inotify lrwx------ 1 root root 64 May 25 14:06 8 -> anon_inode:[signalfd] lrwx------ 1 root root 64 May 25 14:06 9 -> socket:[1675]