From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Down Subject: [PATCH] docs: cgroup: mm: Document why inactive_X + active_X may not equal X Date: Mon, 11 Nov 2019 14:49:58 +0000 Message-ID: <20191111144958.GA11914@chrisdown.name> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=OPnJSf+FsDJ4AK8qgreISZQp/qVRV4crg89KAbDdM7k=; b=C7l91imCRxRt/iXdRWLRpgFZp+d1cU9X9RIrPYVByasB726nYNdqnnPU+D6mL5YSmC ihwV7cizd9tDvrMcKaNzoVQxPLyM5LDI4eAZPTQ7r8KNQ960vI4xRHHlXIeCnT9flJgn DPgoxIo/FKx56KEMNcFDpRr7eoWz9x+qywUn8= Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Morton Cc: Johannes Weiner , Tejun Heo , Roman Gushchin , Michal Hocko , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com 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 --- 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 + 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