On Thu, Feb 12, 2009 at 02:10:37PM +0800, Li Zefan wrote: > 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. Ho-hum... I wonder if we are hitting cgroup_clone() in all that fun... Could you a) add a printk to that sucker b) independently from (a), see if wrapping these syscalls into pid = fork(); if (!pid) { [make a syscall, print something] exit(0); } else if (pid > 0) { waitpid(pid, NULL, 0); } and see what happens... _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers