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Date:   Wed, 23 Nov 2022 17:20:04 -0800
From:   Roman Gushchin <roman.gushchin@linux.dev>
To:     Vlastimil Babka <vbabka@suse.cz>
Cc:     Christoph Lameter <cl@linux.com>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Pekka Enberg <penberg@kernel.org>,
        Hyeonggon Yoo <42.hyeyoo@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Matthew Wilcox <willy@infradead.org>, patches@lists.linux.dev,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 07/12] mm, slab: ignore SLAB_RECLAIM_ACCOUNT with
 CONFIG_SLUB_TINY
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References: <20221121171202.22080-1-vbabka@suse.cz>
 <20221121171202.22080-8-vbabka@suse.cz>
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On Mon, Nov 21, 2022 at 06:11:57PM +0100, Vlastimil Babka wrote:
> SLAB_RECLAIM_ACCOUNT caches allocate their slab pages with
> __GFP_RECLAIMABLE and can help against fragmentation by grouping pages
> by mobility, but on tiny systems mobility grouping is likely disabled
> anyway and ignoring SLAB_RECLAIM_ACCOUNT might instead lead to merging
> of caches that are made incompatible just by the flag.
> 
> Thus with CONFIG_SLUB_TINY, make SLAB_RECLAIM_ACCOUNT ineffective.

Hm, do you see disabling all kernel memory accounting functionality
with COFNIG_SLUB_TINY? I'd say yes. But in this case need to be consistent
and disable it alltogether.

Thanks!