From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id E03006B0038 for ; Sat, 8 Apr 2017 21:45:00 -0400 (EDT) Received: by mail-pg0-f71.google.com with SMTP id a72so103609508pge.10 for ; Sat, 08 Apr 2017 18:45:00 -0700 (PDT) Received: from mail-pf0-x242.google.com (mail-pf0-x242.google.com. [2607:f8b0:400e:c00::242]) by mx.google.com with ESMTPS id o5si2667894pgk.339.2017.04.08.18.45.00 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 08 Apr 2017 18:45:00 -0700 (PDT) Received: by mail-pf0-x242.google.com with SMTP id n11so5026099pfg.2 for ; Sat, 08 Apr 2017 18:44:59 -0700 (PDT) Date: Sun, 9 Apr 2017 09:44:57 +0800 From: Wei Yang Subject: Re: [RFC] calc_memmap_size() isn't accurate and one suggestion to improve Message-ID: <20170409014457.GA24681@WeideMBP.lan> Reply-To: Wei Yang References: <20170328011137.GA8655@WeideMacBook-Pro.local> <20170403091818.GI24661@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="x+6KMIRAuhnl3hBn" Content-Disposition: inline In-Reply-To: <20170403091818.GI24661@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Wei Yang , mgorman@techsingularity.net, jiang.liu@linux.intel.com, akpm@linux-foundation.org, tj@kernel.org, mingo@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org --x+6KMIRAuhnl3hBn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Apr 03, 2017 at 11:18:19AM +0200, Michal Hocko wrote: >On Tue 28-03-17 09:11:37, Wei Yang wrote: >> Hi, masters, >>=20 >> # What I found >>=20 >> I found the function calc_memmap_size() may not be that accurate to get = the >> pages for memmap. >>=20 >> The reason is: >>=20 >> > memmap is allocated on a node base, >> > while the calculation is on a zone base >>=20 >> This applies both to SPARSEMEM and FLATMEM. >>=20 >> For example, on my laptop with 6G memory, all the memmap space is alloca= ted >> from ZONE_NORMAL. > >Please try to be more specific. Why is this a problem? Are you trying to >fix some bad behavior or you want to make it more optimal? > >I am sorry I didn't look closer into your proposal but I am quite busy >and other people are probably in a similar situation. If you want to get >a proper feedback please try to state the problem and be explicit if it >is user observable. Michal Glad to hear from you. Sure, let me do more investigation on this and try some experiment to see whether this change is observable. Have a nice day~ >--=20 >Michal Hocko >SUSE Labs --=20 Wei Yang Help you, Help me --x+6KMIRAuhnl3hBn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJY6ZIZAAoJEKcLNpZP5cTd+IQP+wWiO+ewscdHWxBJkLaoaL7w NWym36GE1vARSpDgTUU9k6WcTWVFz0XnNDB5h3jSPmbD25R8vQao1MEt3eWxbiUB jRQevU6S/l5ng+aJvjjSyuRNSFzJr/iDWZpjJaLemVNDhFlNNFcVgS5ilVNOxtfr OgT4qB0olfoHwQMjq+4xSxDgpzWTeA8TAQPlKjvQLrYEBUu9yAJ3ZwqYks70a0Th 27/gWGso+O5MJ2xSPjl0sbpGWy3UDPf/zr1xHqmiMxU8WJtAXP1IYr98KCKZ+PQA SDudRvRa5CHZmIKM2dY4TAeg30lgO+aqKtXWpD9S8L+UiL6wSbgDuB0UcqVPg49e uQy4fqDoZasHjOhZ41QtOwOgNlMDGyL9Fo2kMX5Jn42hawdxsL8/LWt3ZQ7yLsSN Yz5luQ7zyT6gM8vItdgWH7qc9j4cazZjLnujiegD2c42GI3gkl/RQd+2kJl9CXwU uTJHPIBwKV89ow38PtfiGgmPnb7x+RNw79saQRfMGBxs6Jyz4CMAWFfb8X5tBl+V hlZBM4Su4G6SQ9/emEfgHA5hp0rSOMf6nCfVtHH9/38za6ev6g4jPmMyxLeQIZ2R kyiziwvXF9DuhcJmlugkrQdY+2xauzuMTGYhg+VOqwvu/oLWE8RYONbhREB63vzY wEfttHQB1hazhK1TpeNw =b96m -----END PGP SIGNATURE----- --x+6KMIRAuhnl3hBn-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org