From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH v2] proc: add percpu populated pages count to meminfo Date: Tue, 7 Aug 2018 11:51:41 -0700 Message-ID: <20180807185141.GC3978217@devbig004.ftw2.facebook.com> References: <20180807184723.74919-1-dennisszhou@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180807184723.74919-1-dennisszhou@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dennis Zhou Cc: Andrew Morton , Johannes Weiner , Christoph Lameter , Roman Gushchin , Vlastimil Babka , kernel-team@fb.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Linux API List-Id: linux-api@vger.kernel.org Hello, Dennis. On Tue, Aug 07, 2018 at 11:47:23AM -0700, Dennis Zhou wrote: > From: "Dennis Zhou (Facebook)" > > Currently, percpu memory only exposes allocation and utilization > information via debugfs. This more or less is only really useful for > understanding the fragmentation and allocation information at a > per-chunk level with a few global counters. This is also gated behind a > config. BPF and cgroup, for example, have seen an increase use causing > increased use of percpu memory. Let's make it easier for someone to > identify how much memory is being used. > > This patch adds the "Percpu" stat to meminfo to more easily look up how > much percpu memory is in use. This number includes the cost for all > allocated backing pages and not just isnight at the a unit, per chunk > level. Metadata is excluded. I think excluding metadata is fair because > the backing memory scales with the numbere of cpus and can quickly > outweigh the metadata. It also makes this calculation light. > > Signed-off-by: Dennis Zhou Acked-by: Tejun Heo Andrew, if this looks good, can you please route this? Thanks. -- tejun