From owner-freebsd-hackers@FreeBSD.ORG Tue Nov 13 11:54:55 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 049563BA; Tue, 13 Nov 2012 11:54:55 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id 60A7F8FC08; Tue, 13 Nov 2012 11:54:54 +0000 (UTC) Received: from tom.home (localhost [127.0.0.1]) by kib.kiev.ua (8.14.5/8.14.5) with ESMTP id qADBsk1h037572; Tue, 13 Nov 2012 13:54:46 +0200 (EET) (envelope-from kostikbel@gmail.com) X-DKIM: OpenDKIM Filter v2.5.2 kib.kiev.ua qADBsk1h037572 Received: (from kostik@localhost) by tom.home (8.14.5/8.14.5/Submit) id qADBsjGu037571; Tue, 13 Nov 2012 13:54:45 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Tue, 13 Nov 2012 13:54:45 +0200 From: Konstantin Belousov To: Alan Cox Subject: Re: Memory reserves or lack thereof Message-ID: <20121113115445.GK73505@kib.kiev.ua> References: <20121112133638.GZ73505@kib.kiev.ua> <1352755682.93266.YahooMailClassic@web181701.mail.ne1.yahoo.com> <20121112214808.GH73505@kib.kiev.ua> <50A181C9.7030209@rice.edu> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="xno7jeNlVet1RwPO" Content-Disposition: inline In-Reply-To: <50A181C9.7030209@rice.edu> User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Status: No, score=0.2 required=5.0 tests=ALL_TRUSTED, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on tom.home Cc: alc@freebsd.org, pho@freebsd.org, Sushanth Rai , StevenSears , "freebsd-hackers@freebsd.org" X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Nov 2012 11:54:55 -0000 --xno7jeNlVet1RwPO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 12, 2012 at 05:10:01PM -0600, Alan Cox wrote: > On 11/12/2012 3:48 PM, Konstantin Belousov wrote: > > On Mon, Nov 12, 2012 at 01:28:02PM -0800, Sushanth Rai wrote: > >> This patch still doesn't address the issue of M_NOWAIT calls driving > >> the memory the all the way down to 2 pages, right ? It would be nice to > >> have M_NOWAIT just do non-sleep version of M_WAITOK and M_USE_RESERVE > >> flag to dig deep. > > This is out of scope of the change. But it is required for any further > > adjustements. >=20 > I would suggest a somewhat different response: >=20 > The patch does make M_NOWAIT into a "non-sleep version of M_WAITOK" and= =20 > does reintroduce M_USE_RESERVE as a way to specify "dig deep". >=20 > Currently, both M_NOWAIT and M_WAITOK can drive the cache/free memory=20 > down to two pages. The effect of the patch is to stop M_NOWAIT at two=20 > pages rather than allowing it to continue to zero pages. >=20 > When you say, "This is out of scope ...", I believe that you are=20 > referring to changing two pages into something larger. I agree that=20 > this is out of scope for the current change. I referred exactly to the difference between M_USE_RESERVE set or not. IMO this is what was asked by the question author. So yes, my mean of the 'out of scope' is about tweaking the 'two pages reserve' in some way. --xno7jeNlVet1RwPO Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iEYEARECAAYFAlCiNQQACgkQC3+MBN1Mb4g3HgCfRdJiDZjLzVoW2ncDOfrwMGay DIsAn2jfyPpt6vmGm40KixF/0Qwdz2qV =+XXH -----END PGP SIGNATURE----- --xno7jeNlVet1RwPO--