Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 8 Apr 2021 09:08:37 -0700
From:   Daniel Xu <dxu@dxuuu.xyz>
To:     Christian Brauner <christian.brauner@ubuntu.com>
Cc:     bpf@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        kernel-team@fb.com, jolsa@kernel.org, hannes@cmpxchg.org,
        yhs@fb.com
Subject: Re: [RFC bpf-next 0/1] bpf: Add page cache iterator
Message-ID: <20210408160837.kbqxe3ls6ogjvayc@dlxu-fedora-R90QNFJV>
References: <cover.1617831474.git.dxu@dxuuu.xyz>
 <20210408075117.oqoqspilk3c3xsaa@wittgenstein>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210408075117.oqoqspilk3c3xsaa@wittgenstein>
Precedence: bulk

Hi Christian, thanks for taking a look.

On Thu, Apr 08, 2021 at 09:51:17AM +0200, Christian Brauner wrote:
> On Wed, Apr 07, 2021 at 02:46:10PM -0700, Daniel Xu wrote:
> > There currently does not exist a way to answer the question: "What is in
> > the page cache?". There are various heuristics and counters but nothing
> > that can tell you anything like:
> > 
> >   * 3M from /home/dxu/foo.txt
> >   * 5K from ...
> >   * etc.
> > 
> > The answer to the question is particularly useful in the stacked
> > container world. Stacked containers implies multiple containers are run
> > on the same physical host. Memory is precious resource on some (if not
> 
> Just to clarify: what are "stacked containers"? Do you mean nested
> containers, i.e. containers running within containers?

I mean multiple containers running side by side on the same host.

Thanks,
Daniel