Date: Thu, 01 Nov 2012 08:01:12 -0600 From: Ian Lepore <freebsd@damnhippie.dyndns.org> To: attilio@FreeBSD.org Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, Gleb Smirnoff <glebius@FreeBSD.org>, src-committers@FreeBSD.org Subject: Re: svn commit: r242402 - in head/sys: kern vm Message-ID: <1351778472.1120.117.camel@revolution.hippie.lan> In-Reply-To: <CAJ-FndARMhgCRYwo0%2BS4tZ=At6rHJSz_tsy-OtHRHZKkxL-sig@mail.gmail.com> References: <201210311807.q9VI7IcX000993@svn.freebsd.org> <CAJ-FndDRkBS57e9mzZoJWX5ugJ0KBGxhMSO50KB8Wm8MFudjCA@mail.gmail.com> <1351707964.1120.97.camel@revolution.hippie.lan> <CAJ-FndC7QwpNAjzQTumqTY6Sj_RszXPwc0pbHv2-pRGMqbw0ww@mail.gmail.com> <20121101100814.GB70741@FreeBSD.org> <CAJ-FndARMhgCRYwo0%2BS4tZ=At6rHJSz_tsy-OtHRHZKkxL-sig@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 2012-11-01 at 10:42 +0000, Attilio Rao wrote: > On 11/1/12, Gleb Smirnoff <glebius@freebsd.org> wrote: > > On Wed, Oct 31, 2012 at 06:33:51PM +0000, Attilio Rao wrote: > > A> > Doesn't this padding to cache line size only help x86 processors in an > > A> > SMP kernel? I was expecting to see some #ifdef SMP so that we don't > > pay > > A> > a big price for no gain in small-memory ARM systems and such. But > > maybe > > A> > I'm misunderstanding the reason for the padding. > > A> > > A> I didn't want to do this because this would be meaning that SMP option > > A> may become a completely killer for modules/kernel ABI compatibility. > > > > Do we support loading non-SMP modules on SMP kernel and vice versa? > > Actually that's my point, we do. > > Attilio > > Well we've got other similar problems lurking then. What about a module compiled on an arm system that had #define CACHE_LINE_SIZE 32 and then it gets run on a different arm system whose kernel is compiled with #define CACHE_LINE_SIZE 64? -- Ian
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1351778472.1120.117.camel>