Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753403AbbHTRDO (ORCPT ); Thu, 20 Aug 2015 13:03:14 -0400 Received: from prod-mail-xrelay06.akamai.com ([96.6.114.98]:41301 "EHLO prod-mail-xrelay06.akamai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751676AbbHTRDM (ORCPT ); Thu, 20 Aug 2015 13:03:12 -0400 Date: Thu, 20 Aug 2015 13:03:09 -0400 From: Eric B Munson To: Michal Hocko Cc: Andrew Morton , Vlastimil Babka , Jonathan Corbet , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, linux-api@vger.kernel.org Subject: Re: [PATCH v7 3/6] mm: Introduce VM_LOCKONFAULT Message-ID: <20150820170309.GA11557@akamai.com> References: <1439097776-27695-1-git-send-email-emunson@akamai.com> <1439097776-27695-4-git-send-email-emunson@akamai.com> <20150812115909.GA5182@dhcp22.suse.cz> <20150819213345.GB4536@akamai.com> <20150820075611.GD4780@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="LQksG6bCIzRHxTLp" Content-Disposition: inline In-Reply-To: <20150820075611.GD4780@dhcp22.suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2444 Lines: 62 --LQksG6bCIzRHxTLp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, 20 Aug 2015, Michal Hocko wrote: > On Wed 19-08-15 17:33:45, Eric B Munson wrote: > [...] > > The group which asked for this feature here > > wants the ability to distinguish between LOCKED and LOCKONFAULT regions > > and without the VMA flag there isn't a way to do that. >=20 > Could you be more specific on why this is needed? They want to keep metrics on the amount of memory used in a LOCKONFAULT region versus the address space of the region. >=20 > > Do we know that these last two open flags are needed right now or is > > this speculation that they will be and that none of the other VMA flags > > can be reclaimed? >=20 > I do not think they are needed by anybody right now but that is not a > reason why it should be used without a really strong justification. > If the discoverability is really needed then fair enough but I haven't > seen any justification for that yet. To be completely clear you believe that if the metrics collection is not a strong enough justification, it is better to expand the mm_struct by another unsigned long than to use one of these bits right? --LQksG6bCIzRHxTLp Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJV1ghMAAoJELbVsDOpoOa9h6gP/0wZmVsmQn0ULZ2icCgHa60d Uiij9pmZvI0gmFD0D8Erh4dtHd6xtWts+1N/h7O37ryNlLRTe1EmWuyKBPuzn3+b B4R39SjJNmpRgey4/s3jB6538QZWYO9lKfrbaosv1nEAoNzjmb9vRjZ+zfExGjiQ ILODj7ILv1OJhiKfvlZbl6dkJq719YTi5kAaWbFQ/BFTnSt2PPZUxH3oG2RrNgaS 8R08qH5zyjreWnYVVq2N0FM2p0pAIwOkPTSe7DbNu/W9AThv6TdXeczRMoCWamTi m4xV+j61p6PqrGnCk1bCa2RWxbEV4gxGtNBwZVZOFDnYtWl+5HTqL99oKL3lIvCe adMdBRlY4Q++znx6u0aAghQ1N8EzBEFPCpOyzgyfNKMKz8mxVZGJs2p4LzJ4ETpg +EybJmhNufjzwHXnnD1jZM3h/elEIrdB1mcyRs2w1CYwF7Q3IckUZ1dcz7+Ze2yw sP4MtYfw+24MHvsokdqU8qPbZm2+iqPN1W5UCZOjKo3w5O1FAWJAwpLGiz1mR2L8 k1MKecp4Xc9iFRnFSQ2lUpKS1aOG353wdSC9n8YCNNg5XAg/6LPuFR1A9eQHSfEg evtUcqZHC3aVWfTaEu6JjJQJitQmTSFWEX1jb1vL53ZTFJPwBjJOVAwDm9GVDeiu SKfq8OykFeQNnd6k3HQI =+u4S -----END PGP SIGNATURE----- --LQksG6bCIzRHxTLp-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/