On 9/8/05, Dave Hansen <[EMAIL PROTECTED]> wrote: > On Tue, 2005-09-06 at 12:56 +0900, Magnus Damm wrote: > > This patch for 2.6.13-git5 fixes single node sparsemem support. In the case > > when multiple nodes are used, setup_memory() in arch/i386/mm/discontig.c > > calls > > get_memcfg_numa() which calls memory_present(). The single node case with > > setup_memory() in arch/i386/kernel/setup.c does not call memory_present() > > without this patch, which breaks single node support. > > First of all, this is really a feature addition, not a bug fix. :)
>From the POV that you can use sparsemem on a PC, yes. But from the POV that setup_memory() in arch/i386/kernel/setup.c not includes a call to memory_present(), I think it is a fix. =) While at it, why do we have two copies of setup_memory()? Couldn't NUMA and non-NUMA share the same code? OTOH, NUMA and discontigmem seems very integrated/mixed up and there seems to be much activity in this field so maybe it is nice to keep the NUMA part separated anyway. > The reason we haven't included this so far is that we don't really have > any machines that need sparsemem on i386 that aren't NUMA. So, we > disabled it for now, and probably need to decide first why we need it > before a patch like that goes in. Well, I do not have any hardware here that requires sparsemem either, but I wanted to add NUMA emulation code to be able to run some multiple-memory-nodes tests on a virtual PC in QEMU. And this little patch shows my first step which involved getting sparsememto run on a PC. > I actually have exactly the same patch that you sent out in my tree, but > it's just for testing. Magnus, perhaps we can get some of my testing > patches in good enough shape to put them in -mm so that the non-NUMA > folks can do more sparsemem testing. Well, my NUMA emulation project has been postponed a bit now, but sooner or later I or someone else will need sparsemem on non-NUMA. So getting your testing patches in to -mm seems like a good idea! Thanks! / magnus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/