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From:   Pengfei Li <lpf.vector@gmail.com>
Date:   Tue, 10 Sep 2019 08:52:40 +0800
Message-ID: <CAD7_sbHV=tXrZaBuQuifVznFMUf13hs7t_QcgFVmrCdMHT4Ytg@mail.gmail.com>
Subject: Re: [PATCH 1/5] mm, slab: Make kmalloc_info[] contain all types of names
To:     Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc:     Vlastimil Babka <vbabka@suse.cz>,
        Andrew Morton <akpm@linux-foundation.org>,
        Christopher Lameter <cl@linux.com>, penberg@kernel.org,
        rientjes@google.com, iamjoonsoo.kim@lge.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
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On Tue, Sep 10, 2019 at 2:30 AM Rasmus Villemoes
<linux@rasmusvillemoes.dk> wrote:
>
> On 09/09/2019 18.53, Pengfei Li wrote:
> > On Mon, Sep 9, 2019 at 10:59 PM Vlastimil Babka <vbabka@suse.cz> wrote:
>
> >>>   /*
> >>>    * 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?
> >
> > You are right, I will remove __initconst in v2.
>
> No, __initconst is correct, and should be kept. The string literals
> which the .name pointers point to live in .rodata, and we're copying the
> values of these .name pointers. Nothing refers to something inside
> kmalloc_info[] after init. (It would be a whole different matter if
> struct kmalloc_info_struct consisted of { char name[NN]; unsigned int
> size; }).
>

Thank you for your comment. I will keep it in v3.

I did learn :)


> Rasmus