linux/include
Rafael J. Wysocki 2aede851dd PM / Hibernate: Freeze kernel threads after preallocating memory
There is a problem with the current ordering of hibernate code which
leads to deadlocks in some filesystems' memory shrinkers.  Namely,
some filesystems use freezable kernel threads that are inactive when
the hibernate memory preallocation is carried out.  Those same
filesystems use memory shrinkers that may be triggered by the
hibernate memory preallocation.  If those memory shrinkers wait for
the frozen kernel threads, the hibernate process deadlocks (this
happens with XFS, for one example).

Apparently, it is not technically viable to redesign the filesystems
in question to avoid the situation described above, so the only
possible solution of this issue is to defer the freezing of kernel
threads until the hibernate memory preallocation is done, which is
implemented by this change.

Unfortunately, this requires the memory preallocation to be done
before the "prepare" stage of device freeze, so after this change the
only way drivers can allocate additional memory for their freeze
routines in a clean way is to use PM notifiers.

Reported-by: Christoph <cr2005@u-club.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-16 23:28:52 +02:00
..
acpi Merge branch 'apei-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2011-08-03 21:53:27 -10:00
asm-generic All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
crypto
drm drm: Separate EDID Header Check from EDID Block Check 2011-08-04 14:39:35 +01:00
keys
linux PM / Hibernate: Freeze kernel threads after preallocating memory 2011-10-16 23:28:52 +02:00
math-emu
media [media] V4L: initial driver for ov5642 CMOS sensor 2011-07-27 17:56:09 -03:00
mtd
net tcp: fix build error if !CONFIG_SYN_COOKIES 2011-09-18 21:48:01 -04:00
pcmcia Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6 2011-07-31 06:23:08 -10:00
rdma atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
rxrpc atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
scsi Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2011-08-06 22:56:03 -07:00
sound PM QoS: Minor clean-ups 2011-08-25 15:35:12 +02:00
target target: Make standard INQUIRY return 'not connected' for tpg_virt_lun0 2011-08-22 19:25:35 +00:00
trace Merge branch 'pm-runtime' into pm-for-linus 2011-10-07 23:16:55 +02:00
video OMAP: DSS2: Remove unused opt_clock_available 2011-07-25 10:22:05 +03:00
xen xen/balloon: memory hotplug support for Xen balloon driver 2011-07-25 20:57:08 -07:00
Kbuild