Re: [PATCH] Enable hashdist by default on PowerPC

2009-02-20 Thread David Miller
From: Anton Blanchard Date: Fri, 20 Feb 2009 16:19:56 +1100 > > Hi David, > > > I should probably do this on sparc64 too. > > > > Why don't we just change this thing to CONFIG_64BIT? > > I agree. How does this look? Hmmm... my bad, I think you need to keep the CONFIG_NUMA there too as there

Re: [PATCH] Enable hashdist by default on PowerPC

2009-02-19 Thread Anton Blanchard
Hi David, > I should probably do this on sparc64 too. > > Why don't we just change this thing to CONFIG_64BIT? I agree. How does this look? Anton -- On PowerPC we allocate large boot time hashes on node 0. This leads to an imbalance in the free memory, for example on a 64GB box (4 x 16GB node

Re: [PATCH] Enable hashdist by default on PowerPC

2009-02-18 Thread David Miller
From: Anton Blanchard Date: Wed, 18 Feb 2009 16:11:12 +1100 > @@ -145,9 +145,10 @@ extern void *alloc_large_system_hash(const char > *tablename, > #define HASH_EARLY 0x0001 /* Allocating during early boot? */ > > /* Only NUMA needs hash distribution. > - * IA64 and x86_64 have suf

Re: [PATCH] Enable hashdist by default on PowerPC

2009-02-17 Thread Anton Blanchard
Hi Ben, > You have numbers ? :-) I'm asking mostly because I've been wondering > whether it offsets the 16M pages vs. 4K or 64K pages in term of TLB/ERAT > impact. The speedup is application dependent. Things like linpack usually improve when you throw more memmory at them. The potential slowdo

Re: [PATCH] Enable hashdist by default on PowerPC

2009-02-17 Thread Benjamin Herrenschmidt
> For many HPC applications we are limited by the free available memory on > the smallest node, so even though the same amount of memory is used the > better balancing helps. > > Signed-off-by: Anton Blanchard > --- You have numbers ? :-) I'm asking mostly because I've been wondering whether it

[PATCH] Enable hashdist by default on PowerPC

2009-02-17 Thread Anton Blanchard
On PowerPC we allocate large boot time hashes on node 0. This leads to an imbalance in the free memory, for example on a 64GB box (4 x 16GB nodes): Free memory: Node 0: 97.03% Node 1: 98.54% Node 2: 98.42% Node 3: 98.53% If we switch to using vmalloc (like ia64 and x86-64) things are more balanc