Re: [PATCH 1/3] mm/slab: use percpu allocator for cpu cache

From: Christoph Lameter
Date: Thu Aug 21 2014 - 10:21:37 EST


On Thu, 21 Aug 2014, Joonsoo Kim wrote:

> So, this patch try to use percpu allocator in SLAB. This simplify
> initialization step in SLAB so that we could maintain SLAB code more
> easily.

I thought about this a couple of times but the amount of memory used for
the per cpu arrays can be huge. In contrast to slub which needs just a
few pointers, slab requires one pointer per object that can be in the
local cache. CC Tj.

Lets say we have 300 caches and we allow 1000 objects to be cached per
cpu. That is 300k pointers per cpu. 1.2M on 32 bit. 2.4M per cpu on
64bit.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/