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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 63989C433B4 for ; Thu, 8 Apr 2021 16:08:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4382F610F8 for ; Thu, 8 Apr 2021 16:08:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232230AbhDHQJJ (ORCPT ); Thu, 8 Apr 2021 12:09:09 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:47135 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231655AbhDHQJH (ORCPT ); Thu, 8 Apr 2021 12:09:07 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.nyi.internal (Postfix) with ESMTP id A7F145C00DF; Thu, 8 Apr 2021 12:08:55 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute3.internal (MEProxy); Thu, 08 Apr 2021 12:08:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dxuuu.xyz; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm3; bh=mC9lT507J6RIj+U5nS4hMawdjll gWQu3AF4sHZo0txk=; b=ftKoFL1DidJZ8AA4UiXRBaU5Tu/vdy4sOfZHQQmhepU HFTbJRcZk4OJYHb7DXNl1OHOgfJGsD0r8tiXXEeY730VTP+oE0SnZy8Y1GVsNKXw bLI4yQ8/J2guhtUHQIUQYA3dKLYMe+7xf9I4FGT1eVdicvUi05vrxgSzIH4HIMdV +4KJ+4o6qNs4r/AAmuWFKgdyTGY5ltllEXKqhmP/FzQOY2YCIw2GguWbUAkqhS3t mxlWlEa/p/Efv/FKnhlcqtbnEVEKepAyYZL+GXFx7r+pFIH+J+8tlk8pEd8Mm/TL RBiv9VPfKNNj2SrCDhrrbjjz9sHMFJz4Blvr+seB0Vw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=mC9lT5 07J6RIj+U5nS4hMawdjllgWQu3AF4sHZo0txk=; b=QuGYtViLn86Ts9x5v5g3bd MVi95Jp1JOot0EuVp4/oK46YOgRBpnkpsxCK05+VilcbR8CjelhsaBupaZBiRqD8 36+6xejpOF86GaFL9DZuhdR8GnQQFT5peUrpzpelRPcS+LLYFBtu7oaB699rpKmE 7+Uh9cL5tIZfJQNmxEFuTLdprT8MUmC9RKgt9d+vY0LmiaePWIwrPwGzoTS203cl Y1o8ujJmjsrczLBw+KMiHiLNsAS93ogs+fciMCd80KEdPYJXq/NYdo6A8dcnMUKk naDGagrYNcCUX/44wxC3Ri2u59NRTLRQxY58nNlL+6Ka80F/GNZLHrWIRm0/KUvg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrudejledgleelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne gfrhhlucfvnfffucdljedtmdenucfjughrpeffhffvuffkfhggtggujgesthdtredttddt vdenucfhrhhomhepffgrnhhivghlucgiuhcuoegugihusegugihuuhhurdighiiiqeenuc ggtffrrghtthgvrhhnpeeuuddvjeefffelgfeuveehfeegfeetfeetueduudfhudfhheev leetveduleehjeenucfkphepudeifedruddugedrudefvddrheenucevlhhushhtvghruf hiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegugihusegugihuuhhurdighiii X-ME-Proxy: Received: from dlxu-fedora-R90QNFJV (unknown [163.114.132.5]) by mail.messagingengine.com (Postfix) with ESMTPA id 9C2731080054; Thu, 8 Apr 2021 12:08:53 -0400 (EDT) Date: Thu, 8 Apr 2021 09:08:37 -0700 From: Daniel Xu To: Christian Brauner 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: <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 List-ID: X-Mailing-List: bpf@vger.kernel.org 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