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Message-ID: <3ab3961d-04e5-484d-bc71-2f33ebbefc67@linux.dev>
Date: Mon, 5 Feb 2024 16:08:37 +0800
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Subject: Re: [PATCH 1/1] hugetlb: fix CONFIG_PADATA dependency for non-SMP
 system
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To: Muchun Song <muchun.song@linux.dev>
Cc: Gang Li <ligang.bdlg@bytedance.com>,
 Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
 linux-mm@kvack.org, Randy Dunlap <rdunlap@infradead.org>,
 kernel test robot <lkp@intel.com>
References: <20240204072525.1986626-1-gang.li@linux.dev>
 <f05f658a-78fa-45cd-ad07-11d87b824702@linux.dev>
 <a749cb06-9495-40fc-9192-b019b48eca92@linux.dev>
 <828f990c-11af-42ad-a030-a66dde97a7f2@linux.dev>
 <7472563F-5C2D-4DCB-ACD6-F86D7A18BDF2@linux.dev>
From: Gang Li <gang.li@linux.dev>
In-Reply-To: <7472563F-5C2D-4DCB-ACD6-F86D7A18BDF2@linux.dev>
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On 2024/2/5 15:37, Muchun Song wrote:
> Actually, I did not get it. Why the above code cannot work? The above
> code already make it serialized in one call, right? What do I miss here?
> 
> Thanks.
> 

PADATA consists of two distinct functionality:

One part is `padata_do_multithreaded`, which disregards
order and simply divides tasks into several groups for parallel
execution. My patch use `padata_do_multithreaded`.

The other part is composed of a set of APIs that, while handling data in
an out-of-order parallel manner, can eventually return the data with
ordered sequence. Only `crypto/pcrypt.c` use them. I guess these APIs
are designed specifically for `crypto/pcrypt.c`.
```
padata_alloc
padata_alloc_shell
padata_do_parallel
padata_do_serial
padata_free_shell
padata_free
```