From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: Re: [PATCH] docs: cgroup: mm: Document why inactive_X + active_X may not equal X Date: Mon, 11 Nov 2019 15:53:54 +0100 Message-ID: <20191111145354.GN1396@dhcp22.suse.cz> References: <20191111144958.GA11914@chrisdown.name> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20191111144958.GA11914@chrisdown.name> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Chris Down Cc: Andrew Morton , Johannes Weiner , Tejun Heo , Roman Gushchin , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com On Mon 11-11-19 14:49:58, Chris Down wrote: > This has confused a significant number of people using cgroups inside > Facebook, and some of those outside as well judging by posts like > this[0] (although it's not a problem unique to cgroup v2). If shmem > handling in particular becomes more coherent at some point in the future > -- although that seems unlikely now -- we can change the wording here. > > [0]: https://unix.stackexchange.com/q/525092/10762 > > Signed-off-by: Chris Down > Cc: Andrew Morton > Cc: Johannes Weiner > Cc: Tejun Heo > Cc: Roman Gushchin > Cc: Michal Hocko > Cc: linux-kernel@vger.kernel.org > Cc: cgroups@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: kernel-team@fb.com Acked-by: Michal Hocko > --- > Documentation/admin-guide/cgroup-v2.rst | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst > index 0704552ed94f..0636bcb60b5a 100644 > --- a/Documentation/admin-guide/cgroup-v2.rst > +++ b/Documentation/admin-guide/cgroup-v2.rst > @@ -1289,7 +1289,12 @@ PAGE_SIZE multiple when read back. > inactive_anon, active_anon, inactive_file, active_file, unevictable > Amount of memory, swap-backed and filesystem-backed, > on the internal memory management lists used by the > - page reclaim algorithm > + page reclaim algorithm. > + > + As these represent internal list state (eg. shmem pages are on anon > + memory management lists), inactive_foo + active_foo may not be equal to and anon will move to file list after MADV_FREE. > + the value for the foo counter, since the foo counter is type-based, not > + list-based. > > slab_reclaimable > Part of "slab" that might be reclaimed, such as > -- > 2.24.0 -- Michal Hocko SUSE Labs