Messages in this thread | | | Date | Thu, 28 Oct 2010 17:05:05 -0700 | Subject | Re: [PATCH 6/7] cgroups: Warn if a bindable subsystem calls css_get() | From | Paul Menage <> |
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Maybe re-title this patch to BUG() if a bindable subsystem calls css_get() ?
Paul
On Fri, Oct 22, 2010 at 1:12 AM, Li Zefan <lizf@cn.fujitsu.com> wrote: > For now bindable subsystems should not use css_get/put(), so warn > on this misuse. > > Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> > --- > include/linux/cgroup.h | 7 +++++-- > kernel/cgroup.c | 3 +++ > 2 files changed, 8 insertions(+), 2 deletions(-) > > diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h > index 1e4e1df..10e4e02 100644 > --- a/include/linux/cgroup.h > +++ b/include/linux/cgroup.h > @@ -80,13 +80,15 @@ struct cgroup_subsys_state { > > /* bits in struct cgroup_subsys_state flags field */ > enum { > - CSS_ROOT, /* This CSS is the root of the subsystem */ > - CSS_REMOVED, /* This CSS is dead */ > + CSS_ROOT, /* This CSS is the root of the subsystem */ > + CSS_REMOVED, /* This CSS is dead */ > + CSS_NO_GET, /* Forbid calling css_get/put() */ > }; > > /* Caller must verify that the css is not for root cgroup */ > static inline void __css_get(struct cgroup_subsys_state *css, int count) > { > + BUG_ON(test_bit(CSS_NO_GET, &css->flags)); > atomic_add(count, &css->refcnt); > } > > @@ -119,6 +121,7 @@ static inline bool css_tryget(struct cgroup_subsys_state *css) > { > if (test_bit(CSS_ROOT, &css->flags)) > return true; > + BUG_ON(test_bit(CSS_NO_GET, &css->flags)); > while (!atomic_inc_not_zero(&css->refcnt)) { > if (test_bit(CSS_REMOVED, &css->flags)) > return false; > diff --git a/kernel/cgroup.c b/kernel/cgroup.c > index 12c1f7c..88e265d 100644 > --- a/kernel/cgroup.c > +++ b/kernel/cgroup.c > @@ -936,6 +936,9 @@ static void init_cgroup_css(struct cgroup_subsys_state *css, > css->cgroup = cgrp; > atomic_set(&css->refcnt, 1); > css->flags = 0; > + /* For now, a bindable subsystem should not call css_get/put(). */ > + if (ss->can_bind) > + set_bit(CSS_NO_GET, &css->flags); > css->id = NULL; > if (cgrp == dummytop) > set_bit(CSS_ROOT, &css->flags); > -- > 1.7.0.1 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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