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Date: Tue, 17 Apr 2018 09:47:58 -0500 (CDT)
From: Christopher Lameter <cl@linux.com>
Subject: Re: slab: introduce the flag SLAB_MINIMIZE_WASTE
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To: Mikulas Patocka <mpatocka@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>, Vlastimil Babka <vbabka@suse.cz>, Matthew Wilcox <willy@infradead.org>, Pekka Enberg <penberg@kernel.org>, linux-mm@kvack.org, dm-devel@redhat.com, David Rientjes <rientjes@google.com>, Joonsoo Kim <iamjoonsoo.kim@lge.com>, Andrew Morton <akpm@linux-foundation.org>

On Mon, 16 Apr 2018, Mikulas Patocka wrote:

> If you boot with slub_max_order=10, the kmalloc-8192 cache has 64 pages.
> So yes, it increases the order of all slab caches (although not up to
> 4MB).

Hmmm... Ok. There is another setting slub_min_objects that controls how
many objects to fit into a slab page.

We could change the allocation scheme so that it finds the mininum order
with the minimum waste. Allocator performance will drop though since fewer
object are then in a slab page.

From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christopher Lameter <cl@linux.com>
Subject: Re: slab: introduce the flag SLAB_MINIMIZE_WASTE
Date: Tue, 17 Apr 2018 09:47:58 -0500 (CDT)
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On Mon, 16 Apr 2018, Mikulas Patocka wrote:

> If you boot with slub_max_order=10, the kmalloc-8192 cache has 64 pages.
> So yes, it increases the order of all slab caches (although not up to
> 4MB).

Hmmm... Ok. There is another setting slub_min_objects that controls how
many objects to fit into a slab page.

We could change the allocation scheme so that it finds the mininum order
with the minimum waste. Allocator performance will drop though since fewer
object are then in a slab page.