Date: Tue, 9 Oct 2007 21:30:52 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Darren Reed <darrenr@freebsd.org> Cc: freebsd-fs@FreeBSD.org, Dag-Erling Sm??rgrav <des@des.no>, freebsd-current@FreeBSD.org Subject: Re: ZFS kmem_map too small. Message-ID: <20071009193051.GA13519@garage.freebsd.pl> In-Reply-To: <470BD649.9050505@freebsd.org> References: <20071005000046.GC92272@garage.freebsd.pl> <20071008121523.GM2327@garage.freebsd.pl> <86bqb97mym.fsf@ds4.des.no> <20071008133846.GP2327@garage.freebsd.pl> <470BD649.9050505@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--Qxx1br4bt0+wmkIi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Oct 09, 2007 at 12:28:09PM -0700, Darren Reed wrote: > Pawel Jakub Dawidek wrote: > >... > > > >For i386 one has to set, eg. 'options KVA_PAGES=3D512' to the kernel > >config to be able to define kmem larger than ~700MB. I guess you're > >running amd64, maybe there is similar requirement? > > =20 >=20 > Given how much RAM PCs have these days, why isn't this a default for=20 > GENERIC? >=20 > Or why isn't it at least a tunable rather than an option? This may be a good reason - today's PCs have a lot of RAM and KVA_PAGES splits address space between userland and kernel - the more address space for the kernel, the less address space for the userland. KVA_PAGES=3D512 splits 4GB address space in half, so userland processes can address at most 2GB of memory. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --Qxx1br4bt0+wmkIi Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFHC9brForvXbEpPzQRAq24AKDQ+OUGZ9dwkEXYyuSvKmTG7m31ogCgws3O TnfpmvNtci4dBdOmDiKPbAQ= =xv+V -----END PGP SIGNATURE----- --Qxx1br4bt0+wmkIi--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20071009193051.GA13519>