On Sat, 12 Dec 2015 12:20:57 -0500 Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
> On Sat, Dec 12, 2015 at 07:33:32PM +0300, Vladimir Davydov wrote:
> > On Fri, Dec 11, 2015 at 02:54:11PM -0500, Johannes Weiner wrote:
> > > What CONFIG_INET and CONFIG_LEGACY_KMEM guard inside the memory
> > > controller code is insignificant, having these conditionals is not
> > > worth the complication and fragility that comes with them.
> > >
> > > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> >
> > Acked-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
> >
> > > @@ -4374,17 +4342,11 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
> > > {
> > > struct mem_cgroup *memcg = mem_cgroup_from_css(css);
> > >
> > > -#ifdef CONFIG_INET
> > > if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
> > > static_branch_dec(&memcg_sockets_enabled_key);
> > > -#endif
> > > -
> > > - memcg_free_kmem(memcg);
> >
> > I wonder where the second call to memcg_free_kmem comes from. Luckily,
> > it couldn't result in a breakage. And now it's removed.
>
> Lol, I had to double check my trees to see what's going on as I don't
> remember this being part of the patch. But it looks like the double
> free came from the "net: drop tcp_memcontrol.c" patch and I must have
> removed it again during conflict resolution when rebasing this patch
> on top of yours. I must have thought git's auto-merge added it.
>
> However, this causes an underflow of the kmem static branch, so we
> will have to fix this directly in "net: drop tcp_memcontrol.c".
>
> Andrew, could you please pick this up? However, it's important to also
> then remove the hunk above from THIS patch, the one that deletes the
> excessive memcg_free_kmem(). We need exactly one memcg_free_kmem() in
> mem_cgroup_css_free(). :-)
So you want to retain
mm-memcontrol-reign-in-the-config-space-madness.patch's removal of the
ifdef CONFIG_INET?
What I have is
Against net-drop-tcp_memcontrolc.patch:
--- a/mm/memcontrol.c~net-drop-tcp_memcontrolc-fix
+++ a/mm/memcontrol.c
@@ -4421,8 +4421,6 @@ static void mem_cgroup_css_free(struct c
static_branch_dec(&memcg_sockets_enabled_key);
#endif
- memcg_free_kmem(memcg);
-
__mem_cgroup_free(memcg);
}
and against mm-memcontrol-reign-in-the-config-space-madness.patch:
--- a/mm/memcontrol.c~mm-memcontrol-reign-in-the-config-space-madness-fix
+++ a/mm/memcontrol.c
@@ -4380,6 +4380,8 @@ static void mem_cgroup_css_free(struct c
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
static_branch_dec(&memcg_sockets_enabled_key);
+ memcg_free_kmem(memcg);
+
if (memcg->tcp_mem.active)
static_branch_dec(&memcg_sockets_enabled_key);
Producing
static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
static_branch_dec(&memcg_sockets_enabled_key);
memcg_free_kmem(memcg);
if (memcg->tcp_mem.active)
static_branch_dec(&memcg_sockets_enabled_key);
__mem_cgroup_free(memcg);
}
And I did s/reign/rein/;)
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