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Date:   Wed, 11 Oct 2023 15:31:50 +0200
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Subject: Re: [RESEND PATCH] mm: slab: Do not create kmalloc caches smaller
 than arch_slab_minalign()
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To:     Catalin Marinas <catalin.marinas@arm.com>
Cc:     linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
        Peter Collingbourne <pcc@google.com>,
        Petr Tesarik <petr.tesarik.ext@huawei.com>
References: <20231006163934.3273940-1-catalin.marinas@arm.com>
 <a09a6fe5-2352-8922-e575-54bf74ae64e5@suse.cz> <ZSPiAE6c4rzhilRy@arm.com>
From:   Vlastimil Babka <vbabka@suse.cz>
In-Reply-To: <ZSPiAE6c4rzhilRy@arm.com>
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On 10/9/23 13:20, Catalin Marinas wrote:
>> >  mm/slab_common.c | 7 +++++--
>> >  1 file changed, 5 insertions(+), 2 deletions(-)
>> > 
>> > diff --git a/mm/slab_common.c b/mm/slab_common.c
>> > index cd71f9581e67..8b45922ed295 100644
>> > --- a/mm/slab_common.c
>> > +++ b/mm/slab_common.c
>> > @@ -895,10 +895,13 @@ void __init setup_kmalloc_cache_index_table(void)
>> >  
>> >  static unsigned int __kmalloc_minalign(void)
>> >  {
>> > +	unsigned int minalign = dma_get_cache_alignment();
>> > +
>> >  	if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) &&
>> >  	    is_swiotlb_allocated())
>> > -		return ARCH_KMALLOC_MINALIGN;
>> > -	return dma_get_cache_alignment();
>> > +		minalign = ARCH_KMALLOC_MINALIGN;
>> > +
>> > +	return ALIGN(minalign, arch_slab_minalign());
>> 
>> Could it be max() instead of ALIGN()? It would be more obvious, at least to
>> me :)
> 
> Yeah, max() would do since they are all a power of two. Do you want me
> to repost?

No need, picked up and changed locally. Thanks!