kernel-ark/init
Rafael J. Wysocki 8314418629 Freezer: make kernel threads nonfreezable by default
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
..
calibrate.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00
do_mounts_initrd.c Freezer: make kernel threads nonfreezable by default 2007-07-17 10:23:02 -07:00
do_mounts_md.c [PATCH] md: remove MAX_MD_DEVS which is an arbitrary limit 2006-10-03 08:04:18 -07:00
do_mounts_rd.c
do_mounts.c init: wait for asynchronously scanned block devices 2007-07-16 09:05:45 -07:00
do_mounts.h Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
initramfs.c [PATCH] Add retain_initrd boot option 2007-02-11 10:51:24 -08:00
Kconfig Make SLUB the default allocator 2007-07-17 10:23:02 -07:00
main.c adjust nosmp handling 2007-07-16 09:05:47 -07:00
Makefile [PATCH] disable init/initramfs.c 2007-02-11 10:51:25 -08:00
noinitramfs.c [PATCH] disable init/initramfs.c 2007-02-11 10:51:25 -08:00
version.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00