On Wed, Sep 23, 2015 at 05:07:29PM -0400, Tejun Heo wrote: > inode_cgwb_enabled() gates cgroup writeback support. If it returns > true, each inode is attached to the corresponding memory domain which > gets mapped to io domain. It currently only tests whether the > filesystem and bdi support cgroup writeback; however, cgroup writeback > support doesn't work on traditional hierarchies and thus it should > also test whether memcg and iocg are on the default hierarchy. > > This caused traditional hierarchy setups to hit the cgroup writeback > path inadvertently and ended up creating separate writeback domains > for each memcg and mapping them all to the root iocg uncovering a > couple issues in the cgroup writeback path. > > cgroup writeback was never meant to be enabled on traditional > hierarchies. Make inode_cgwb_enabled() test whether both memcg and > iocg are on the default hierarchy. > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> > Reported-by: Artem Bityutskiy <dedekind1@xxxxxxxxx> > Reported-by: Dexuan Cui <decui@xxxxxxxxxxxxx> > Link: http://lkml.kernel.org/g/1443012552.19983.209.camel@xxxxxxxxx > Link: http://lkml.kernel.org/g/f30d4a6aa8a546ff88f73021d026a453@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Applying to cgroup/for-4.3-fixes. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
