linux/include
Tejun Heo 3b514d24e2 cgroup: skip refcnting on normal root csses and cgrp_dfl_root self css
9395a45004 ("cgroup: enable refcnting for root csses") enabled
reference counting for root csses (cgroup_subsys_states) so that
cgroup's self csses can be used to manage the lifetime of the
containing cgroups.

Unfortunately, this change was incorrect.  During early init,
cgrp_dfl_root self css refcnt is used.  percpu_ref can't initialized
during early init and its initialization is deferred till
cgroup_init() time.  This means that cpu was using percpu_ref which
wasn't properly initialized.  Due to the way percpu variables are laid
out on x86, this didn't blow up immediately on x86 but ended up
incrementing and decrementing the percpu variable at offset zero,
whatever it may be; however, on other archs, this caused fault and
early boot failure.

As cgroup self csses for root cgroups of non-dfl hierarchies need
working refcounting, we can't revert 9395a45004.  This patch adds
CSS_NO_REF which explicitly inhibits reference counting on the css and
sets it on all normal (non-self) csses and cgroup_dfl_root self css.

v2: cgrp_dfl_root.self is the offending one.  Set the flag on it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Fixes: 9395a45004 ("cgroup: enable refcnting for root csses")
2014-05-16 13:22:47 -04:00
..
acpi IOMMU Upates for Linux v3.15 2014-04-05 18:46:26 -07:00
asm-generic mm: use paravirt friendly ops for NUMA hinting ptes 2014-04-18 16:40:09 -07:00
clocksource
crypto crypto: export NULL algorithms defines 2014-03-21 21:54:26 +08:00
drm Merge branch 'drm-next-3.15-wip' of git://people.freedesktop.org/~deathsimple/linux into drm-next 2014-04-19 11:16:02 +10:00
dt-bindings The clock framework changes for 3.15 look similar to past pull requests. 2014-04-05 18:39:18 -07:00
keys
kvm ARM: KVM: fix non-VGIC compilation 2014-03-06 09:47:42 +01:00
linux cgroup: skip refcnting on normal root csses and cgrp_dfl_root self css 2014-05-16 13:22:47 -04:00
math-emu
media [media] rc-core: remove generic scancode filter 2014-04-06 11:30:29 -03:00
memory
misc
net net: sctp: cache auth_enable per endpoint 2014-04-18 18:32:00 -04:00
pcmcia
ras
rdma Merge branches 'core', 'cxgb4', 'ip-roce', 'iser', 'misc', 'mlx4', 'nes', 'ocrdma', 'qib', 'sgwrapper', 'srp' and 'usnic' into for-next 2014-04-03 08:30:17 -07:00
rxrpc
scsi scsi: Make sure cmd_flags are 64-bit 2014-04-09 20:26:20 -06:00
sound ALSA: cs8427: separate HW initialization 2014-04-03 14:59:48 +02:00
target target/sbc: Add sbc_dif_read_strip software emulation 2014-04-07 01:48:57 -07:00
trace This includes the final patch to clean up and fix the issue with the 2014-04-12 13:06:10 -07:00
uapi Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux 2014-04-19 10:35:30 -07:00
video fbdev changes for 3.15 (OMAP) 2014-04-07 10:47:51 -07:00
xen xen/acpi-processor: fix enabling interrupts on syscore_resume 2014-03-18 14:40:20 +00:00
Kbuild