From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH] powerpc: force 4k update_flash block and list sizes From: Michael Ellerman To: Arnd Bergmann In-Reply-To: <200611081028.32038.arnd@arndb.de> References: <1162943615.13499.15.camel@sinatra.austin.ibm.com> <1162960202.14254.3.camel@sinatra.austin.ibm.com> <1162960860.20271.13.camel@localhost.localdomain> <200611081028.32038.arnd@arndb.de> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-8wwkFdMTVdG+Ou4jVLu/" Date: Thu, 09 Nov 2006 09:40:18 +1100 Message-Id: <1163025618.7630.2.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Paul Mackerras , Michael Neuling Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-8wwkFdMTVdG+Ou4jVLu/ Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Wed, 2006-11-08 at 10:28 +0100, Arnd Bergmann wrote: > On Wednesday 08 November 2006 05:41, Michael Ellerman wrote: > > Just being picky .. but why did you decide to use the slab cache? Does > > it make the code neater? I would have thought you could guarantee 4k > > alignment some other way, and it seems slightly odd to use the slab > > cache for something you only do once .. >=20 > There are not so many allocators available. kmalloc does not guarantee > alignment beyond a few bytes and the buddy allocator and vmalloc don't > give you allocations smaller than PAGE_SIZE. Yeah, I assumed kmalloc aligned on the size of the allocation, but it doesn't looking at the code. We could set ARCH_KMALLOC_MINALIGN to 4k, but that aligns all caches which is probably not what we want. > The ehca people had the same problem, and I could imagine there are > others with similar issues. How about adding a special slab allocator > architecture-wide that gives out aligned 4k chunks independent of > page size? Yeah that sounds like a plan, I'm sure there's other code around that could use it. cheers --=20 Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person --=-8wwkFdMTVdG+Ou4jVLu/ Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (GNU/Linux) iD8DBQBFUlzRdSjSd0sB4dIRAgkWAJ9kKMJIauCJQ7TXnWCnyIN5PDa+YgCffZcO bPsnVdNZlK1Y+k4HAOg5oKg= =6UZa -----END PGP SIGNATURE----- --=-8wwkFdMTVdG+Ou4jVLu/--