From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81128C433B4 for ; Thu, 8 Apr 2021 07:51:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E826061157 for ; Thu, 8 Apr 2021 07:51:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E826061157 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ubuntu.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2CD506B0078; Thu, 8 Apr 2021 03:51:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 255B86B007E; Thu, 8 Apr 2021 03:51:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0CFE46B0080; Thu, 8 Apr 2021 03:51:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0103.hostedemail.com [216.40.44.103]) by kanga.kvack.org (Postfix) with ESMTP id E0BA96B0078 for ; Thu, 8 Apr 2021 03:51:24 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 8EC524FF4 for ; Thu, 8 Apr 2021 07:51:24 +0000 (UTC) X-FDA: 78008429688.13.103A555 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf01.hostedemail.com (Postfix) with ESMTP id 86C5C5001526 for ; Thu, 8 Apr 2021 07:51:23 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 96FD661155; Thu, 8 Apr 2021 07:51:20 +0000 (UTC) Date: Thu, 8 Apr 2021 09:51:17 +0200 From: Christian Brauner To: Daniel Xu 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: <20210408075117.oqoqspilk3c3xsaa@wittgenstein> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 86C5C5001526 X-Stat-Signature: h8cs1s5webkwnjmysy4y79heuqz8da35 Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf01; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: none/none X-HE-Tag: 1617868283-14606 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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? Christian