Messages in this thread | | | Date | Sat, 12 Jan 2002 18:42:16 +0100 | From | Andrea Arcangeli <> | Subject | Re: [PATCH] 1-2-3 GB |
| |
On Sat, Jan 12, 2002 at 12:26:35PM -0500, Albert D. Cahalan wrote: > Andrea Arcangeli writes: > > On Fri, Jan 11, 2002 at 11:32:37PM -0800, H. Peter Anvin wrote: > >> By author: rwhron@earthlink.net > > >>> --- linux.aa2/arch/i386/config.in Fri Jan 11 20:57:58 2002 > >>> +++ linux/arch/i386/config.in Fri Jan 11 22:20:32 2002 > >>> @@ -169,7 +169,11 @@ > >>> if [ "$CONFIG_HIGHMEM64G" = "y" ]; then > >>> define_bool CONFIG_X86_PAE y > >>> else > >>> - bool '3.5GB user address space' CONFIG_05GB > >>> + choice 'Maximum Virtual Memory' \ > >>> + "3GB CONFIG_1GB \ > >>> + 2GB CONFIG_2GB \ > >>> + 1GB CONFIG_3GB \ > >>> + 05GB CONFIG_05GB" 3GB ^^ this should be 3.5GB btw > >>> fi > >> > >> Calling this "Maximum Virtual Memory" is misleading at best. This is > >> best described as "kernel:user split" (3:1, 2:2, 1:3, 3.5:0.5); > >> "maximum virtual memory" sounds to me a lot like the opposite of what > >> your parameter is. > > > > actually it is really max virtual memory.. but from the user point of > > view, user is supposed to care about the virtual memory he can manage, > > not about what the kernel will do with the rest. So if the user wants > > 3GB of virtual memory available to each task he will select 3GB. I > > really don't mind if you want to change it from the kernel point of > > view, but given it's the user who's supposed to compile it, also the > > current patch looks good enough to me. > > The numbers are wrong anyway, because of vmalloc() and PCI space. > The PCI space is motherboard-dependent AFAIK, but you could at > least account for the 128 MB vmalloc() area:
looks dirty, the size of the kernel direct mapping is mainly in function of #defines that can be changed freely, they're not constant in function of CONFIG_1G etc.. and it changes also in function of smp/up/4G/64G options. The 3GB/2GB/1GB/3.5GB visible into the menuconfig are exact instead. So I wouldn't mention inprecise stuff that can changed under us (and the exact size of the kernel direct mapping doesn't matter to the user anyways I think [and if it matters I think it means he's skilled enough to know about vmalloc space ;) ]).
> > user virtual space / non-kmap physical memory > > 3584/384 > 3072/896 > 2048/1920 > 1024/2944 (sure this works, even for syscalls w/ bad pointers?) > 512/3456 (sure this works, even for syscalls w/ bad pointers?)
Andrea - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |