Make sure you test this properly under low memory situations.
On Fri, Feb 17, 2006 at 01:01:48PM -0500, Jun'ichi Nomura wrote:
> This patch provides common functions to create symlinks in sysfs
> between stacked device and its slaves.
dm_swap_table() mustn't block waiting for memory to become
free (except in a controlled way e.g. with a mempool, but
it would need more than that here).
Here, dm_swap_table() leads to kmalloc() getting called
in sysfs_add_link().
[e.g. Consider the extreme case where the dm device
you're changing is your swap device. While dm_swap_table()
runs, no I/O will get through to your swap device.]
If you can't avoid the sysfs code allocating memory, then
you must find a way of doing it before the dm suspend or
after the dm resume.
e.g. Do the sysfs memory allocations for the links prior to
the dm suspend [which may have happened in a previous system call]
and then use a different function to move them into place during
dm_swap_table() without performing further memory allocations?
[Lazy workaround is to set PF_MEMALLOC again...]
Alasdair
--
[email protected]
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
