Re: [PATCH v7 08/19] mm: memcg/slab: save obj_cgroup for non-root slab objects

From: Naresh Kamboju <naresh.kamboju@linaro.org>
To: Roman Gushchin <guro@fb.com>
Cc: linux-mips@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Christoph Lameter <cl@linux.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Michal Hocko <mhocko@kernel.org>,
	Shakeel Butt <shakeelb@google.com>, linux-mm <linux-mm@kvack.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	Kernel Team <kernel-team@fb.com>,
	open list <linux-kernel@vger.kernel.org>,
	lkft-triage@lists.linaro.org
Subject: Re: [PATCH v7 08/19] mm: memcg/slab: save obj_cgroup for non-root slab objects
Date: Fri, 17 Jul 2020 11:04:13 +0530	[thread overview]
Message-ID: <CA+G9fYsvkrVJE-Aiqrkv0UG5fBWrNQ-fEvLeDgEtL5htr3m9wg@mail.gmail.com> (raw)
In-Reply-To: <20200716200744.GB13387@carbon.dhcp.thefacebook.com>

On Fri, 17 Jul 2020 at 01:38, Roman Gushchin <guro@fb.com> wrote:
>
> On Thu, Jul 16, 2020 at 10:25:01PM +0530, Naresh Kamboju wrote:
> > On Tue, 23 Jun 2020 at 23:11, Roman Gushchin <guro@fb.com> wrote:
> > >
> > > Store the obj_cgroup pointer in the corresponding place of
> > > page->obj_cgroups for each allocated non-root slab object.  Make sure that
> > > each allocated object holds a reference to obj_cgroup.
> > >
> > > Objcg pointer is obtained from the memcg->objcg dereferencing in
> > > memcg_kmem_get_cache() and passed from pre_alloc_hook to post_alloc_hook.
> > > Then in case of successful allocation(s) it's getting stored in the
> > > page->obj_cgroups vector.
> > >
> > > The objcg obtaining part look a bit bulky now, but it will be simplified
> > > by next commits in the series.
> > >
> > > Signed-off-by: Roman Gushchin <guro@fb.com>
> > > Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
> > > Reviewed-by: Shakeel Butt <shakeelb@google.com>
> > > ---
> > >  include/linux/memcontrol.h |  3 +-
> > >  mm/memcontrol.c            | 14 +++++++--
> > >  mm/slab.c                  | 18 +++++++-----
> > >  mm/slab.h                  | 60 ++++++++++++++++++++++++++++++++++----
> > >  mm/slub.c                  | 14 +++++----
> > >  5 files changed, 88 insertions(+), 21 deletions(-)


> > >
> >
> > I am not sure if this is the related patch or not that is causing
> > mips architecture build failure on linux -next.
>
> Hello, Naresh!
>
> Thank you for the report, interesting...
> There is nothing arch-specific in the code, so there must be something
> compiler-dependent. My wild guess is that the problem is caused by a memory
> allocation from the memcg_slab_post_alloc_hook(), but it's added by a later
> patch in the series. So if it really fails at this patch, there must be something
> different. I'll try to reproduce it, but I have to install the MIPS toolchain first,
> so it might take some time. If it creates some troubles, can you, please, check
> if s/__always_inline/inline helps?

sed -i -e 's#__always_inline#inline#g' mm/slub.c ->> then builds fine.

-  Naresh