From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: 64bit kernel is huge From: Michael Ellerman To: Benjamin Herrenschmidt In-Reply-To: <1254125220.8421.21.camel@pasglop> References: <20090928074503.GB16073@kryten> <1254125220.8421.21.camel@pasglop> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-5oBbbYaePvaaHvxXoDyW" Date: Mon, 28 Sep 2009 19:13:28 +1000 Message-Id: <1254129208.5959.7.camel@concordia> Mime-Version: 1.0 Cc: linuxppc-dev@lists.ozlabs.org, Anton Blanchard Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-5oBbbYaePvaaHvxXoDyW Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Mon, 2009-09-28 at 18:07 +1000, Benjamin Herrenschmidt wrote: > On Mon, 2009-09-28 at 17:45 +1000, Anton Blanchard wrote: > > Hi, > >=20 > > I've found at least one machine that wont boot 2.6.31-rc* with a=20 > > pseries_defconfig. If I move real-base from 0xc00000 to 0xd00000 it > > boots fine. > >=20 > > # size vmlinux > > text data bss dec hex filename > > 9812942 1982496 1105228 12900666 c4d93a vmlinux > >=20 > > Looks like we blow right through the 12MB mark. It desperately needs to= eat > > less and lose weight. > > 262144 kstat_irqs_all > > 131072 irq_desc > > 16384 irq_stat > >=20 > > Could we dynamically allocate our irq structures? >=20 > We still want one big array, unless we go to sparse IRQ numbering like > x86 but we'd have to also adapt the remapping stuff. Definitely to put > on a list somewhere for people who want to pick up something to do :-) Actually I've already been looking at it. The easy step is to enable SPARSE_IRQ, the harder step is to get rid of our irq_map. But that's not that big. I'll try and get them polished for the next merge window. > It's hard to properly dynamically size it. I'd rather have a "capacity" > of _lots_ and sparsely populate the array (a tree ?) because we never > know with MSIs etc... how many we'll really need. >=20 > At the -very-least- we could make NR_IRQS a CONFIG option. Yeah I have a patch for that too, I'll post it. It's no good for distros but for custom kernels it could be quite handy, small partitions with virtual most things don't really need many interrupts. cheers --=-5oBbbYaePvaaHvxXoDyW Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAkrAfjQACgkQdSjSd0sB4dLZbQCgp5lNdjfBuAjaqjxWZ2v7B4bo exIAoJSmjJnz9ixXWDh50SgvJ+MS4URd =RSQ+ -----END PGP SIGNATURE----- --=-5oBbbYaePvaaHvxXoDyW--