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Subject: Re: [PATCH 1/5] mm, slab: Make kmalloc_info[] contain all types of
 names
To:     Pengfei Li <lpf.vector@gmail.com>, akpm@linux-foundation.org
Cc:     cl@linux.com, penberg@kernel.org, rientjes@google.com,
        iamjoonsoo.kim@lge.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <20190903160430.1368-1-lpf.vector@gmail.com>
 <20190903160430.1368-2-lpf.vector@gmail.com>
From:   Vlastimil Babka <vbabka@suse.cz>
Message-ID: <4e9a237f-2370-0f55-34d2-1fbb9334bf88@suse.cz>
Date:   Mon, 9 Sep 2019 16:59:02 +0200
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On 9/3/19 6:04 PM, Pengfei Li wrote:
> There are three types of kmalloc, KMALLOC_NORMAL, KMALLOC_RECLAIM
> and KMALLOC_DMA.
> 
> The name of KMALLOC_NORMAL is contained in kmalloc_info[].name,
> but the names of KMALLOC_RECLAIM and KMALLOC_DMA are dynamically
> generated by kmalloc_cache_name().
> 
> This patch predefines the names of all types of kmalloc to save
> the time spent dynamically generating names.

As I said, IMHO it's more useful that we don't need to allocate the 
names dynamically anymore, and it's simpler overall.

> Signed-off-by: Pengfei Li <lpf.vector@gmail.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

>   /*
>    * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
>    * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
>    * kmalloc-67108864.
>    */
>   const struct kmalloc_info_struct kmalloc_info[] __initconst = {

BTW should it really be an __initconst, when references to the names 
keep on living in kmem_cache structs? Isn't this for data that's 
discarded after init?