Messages in this thread | | | Date | Thu, 12 Feb 2009 14:10:37 +0800 | From | Li Zefan <> | Subject | Re: [cgroup or VFS ?] WARNING: at fs/namespace.c:636 mntput_no_expire+0xac/0xf2() |
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Li Zefan wrote: > Al Viro wrote: >> On Mon, Feb 09, 2009 at 12:40:46AM -0800, Andrew Morton wrote: >>>> Thread 1: >>>> for ((; ;)) >>>> { >>>> mount -t cgroup -o cpuset xxx /mnt > /dev/null 2>&1 >>>> mkdir /mnt/0 > /dev/null 2>&1 >>>> rmdir /mnt/0 > /dev/null 2>&1 >>>> umount /mnt > /dev/null 2>&1 >>>> } >>>> >>>> Thread 2: >>>> { >>>> mount -t cpuset xxx /mnt > /dev/null 2>&1 >>>> umount /mnt > /dev/null 2>&1 >>>> } >> How cute... Same mountpoint in both, so these mount(2) will sometimes >> fail (cgroup picks the same sb on the same options, AFAICS) and fail >> silently due to these redirects... >> >> That's a lovely way to stress-test a large part of ro-bind stuff *and* >> umount()-related code. Could you do C equivalent of the above (just >> the same syscalls in loop, nothing fancier) and do time-stamped strace? >> > > Sure, I'll write a C version and try to reproduce the warning. >
Unfortunately, the C equivalent can't reproduce the warning, I've run the test for the whole night. :( While using the script, often I can trigger the warning in several mins.
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