Received-SPF: pass (google.com: domain of linux-crypto+bounces-2698-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <bf2a5631-79cc-414e-82f0-6b45e487c8d9@roeck-us.net>
Date: Sun, 17 Mar 2024 17:13:57 -0700
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v7] crypto: scompress: remove memcpy if sg_nents is 1 and
 pages are lowmem
Content-Language: en-US
To: Barry Song <21cnbao@gmail.com>
Cc: herbert@gondor.apana.org.au, davem@davemloft.net,
 linux-crypto@vger.kernel.org, akpm@linux-foundation.org, chrisl@kernel.org,
 sjenning@redhat.com, vitaly.wool@konsulko.com, linux-kernel@vger.kernel.org,
 Barry Song <v-songbaohua@oppo.com>, Johannes Weiner <hannes@cmpxchg.org>,
 Nhat Pham <nphamcs@gmail.com>, Yosry Ahmed <yosryahmed@google.com>,
 Chengming Zhou <zhouchengming@bytedance.com>
References: <20240301192745.14987-1-21cnbao@gmail.com>
 <aaa8b7d7-5abe-47bf-93f6-407942436472@roeck-us.net>
 <CAGsJ_4wWEdxk0qNV89bL0zeGaXUBb7h92mdNeRCgcUCY5C84ww@mail.gmail.com>
From: Guenter Roeck <linux@roeck-us.net>
Autocrypt: addr=linux@roeck-us.net; keydata=
 xsFNBE6H1WcBEACu6jIcw5kZ5dGeJ7E7B2uweQR/4FGxH10/H1O1+ApmcQ9i87XdZQiB9cpN
 RYHA7RCEK2dh6dDccykQk3bC90xXMPg+O3R+C/SkwcnUak1UZaeK/SwQbq/t0tkMzYDRxfJ7
 nyFiKxUehbNF3r9qlJgPqONwX5vJy4/GvDHdddSCxV41P/ejsZ8PykxyJs98UWhF54tGRWFl
 7i1xvaDB9lN5WTLRKSO7wICuLiSz5WZHXMkyF4d+/O5ll7yz/o/JxK5vO/sduYDIlFTvBZDh
 gzaEtNf5tQjsjG4io8E0Yq0ViobLkS2RTNZT8ICq/Jmvl0SpbHRvYwa2DhNsK0YjHFQBB0FX
 IdhdUEzNefcNcYvqigJpdICoP2e4yJSyflHFO4dr0OrdnGLe1Zi/8Xo/2+M1dSSEt196rXaC
 kwu2KgIgmkRBb3cp2vIBBIIowU8W3qC1+w+RdMUrZxKGWJ3juwcgveJlzMpMZNyM1jobSXZ0
 VHGMNJ3MwXlrEFPXaYJgibcg6brM6wGfX/LBvc/haWw4yO24lT5eitm4UBdIy9pKkKmHHh7s
 jfZJkB5fWKVdoCv/omy6UyH6ykLOPFugl+hVL2Prf8xrXuZe1CMS7ID9Lc8FaL1ROIN/W8Vk
 BIsJMaWOhks//7d92Uf3EArDlDShwR2+D+AMon8NULuLBHiEUQARAQABzTJHdWVudGVyIFJv
 ZWNrIChMaW51eCBhY2NvdW50KSA8bGludXhAcm9lY2stdXMubmV0PsLBgQQTAQIAKwIbAwYL
 CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAlVcphcFCRmg06EACgkQyx8mb86fmYFg0RAA
 nzXJzuPkLJaOmSIzPAqqnutACchT/meCOgMEpS5oLf6xn5ySZkl23OxuhpMZTVX+49c9pvBx
 hpvl5bCWFu5qC1jC2eWRYU+aZZE4sxMaAGeWenQJsiG9lP8wkfCJP3ockNu0ZXXAXwIbY1O1
 c+l11zQkZw89zNgWgKobKzrDMBFOYtAh0pAInZ9TSn7oA4Ctejouo5wUugmk8MrDtUVXmEA9
 7f9fgKYSwl/H7dfKKsS1bDOpyJlqhEAH94BHJdK/b1tzwJCFAXFhMlmlbYEk8kWjcxQgDWMu
 GAthQzSuAyhqyZwFcOlMCNbAcTSQawSo3B9yM9mHJne5RrAbVz4TWLnEaX8gA5xK3uCNCeyI
 sqYuzA4OzcMwnnTASvzsGZoYHTFP3DQwf2nzxD6yBGCfwNGIYfS0i8YN8XcBgEcDFMWpOQhT
 Pu3HeztMnF3HXrc0t7e5rDW9zCh3k2PA6D2NV4fews9KDFhLlTfCVzf0PS1dRVVWM+4jVl6l
 HRIAgWp+2/f8dx5vPc4Ycp4IsZN0l1h9uT7qm1KTwz+sSl1zOqKD/BpfGNZfLRRxrXthvvY8
 BltcuZ4+PGFTcRkMytUbMDFMF9Cjd2W9dXD35PEtvj8wnEyzIos8bbgtLrGTv/SYhmPpahJA
 l8hPhYvmAvpOmusUUyB30StsHIU2LLccUPPOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq
 7kpKABxN2MqeuqGr02DpS9883d/t7ontxasXoEz2GTioevvRmllJlPQERVxM8gQoNg22twF7
 pB/zsrIjxkE9heE4wYfN1AyzT+AxgYN6f8hVQ7Nrc9XgZZe+8IkuW/Nf64KzNJXnSH4u6nJM
 J2+Dt274YoFcXR1nG76Q259mKwzbCukKbd6piL+VsT/qBrLhZe9Ivbjq5WMdkQKnP7gYKCAi
 pNVJC4enWfivZsYupMd9qn7Uv/oCZDYoBTdMSBUblaLMwlcjnPpOYK5rfHvC4opxl+P/Vzyz
 6WC2TLkPtKvYvXmdsI6rnEI4Uucg0Au/Ulg7aqqKhzGPIbVaL+U0Wk82nz6hz+WP2ggTrY1w
 ZlPlRt8WM9w6WfLf2j+PuGklj37m+KvaOEfLsF1v464dSpy1tQVHhhp8LFTxh/6RWkRIR2uF
 I4v3Xu/k5D0LhaZHpQ4C+xKsQxpTGuYh2tnRaRL14YMW1dlI3HfeB2gj7Yc8XdHh9vkpPyuT
 nY/ZsFbnvBtiw7GchKKri2gDhRb2QNNDyBnQn5mRFw7CyuFclAksOdV/sdpQnYlYcRQWOUGY
 HhQ5eqTRZjm9z+qQe/T0HQpmiPTqQcIaG/edgKVTUjITfA7AJMKLQHgp04Vylb+G6jocnQQX
 JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAlVcpi8FCRmg08MACgkQyx8mb86fmYHNRQ/+
 J0OZsBYP4leJvQF8lx9zif+v4ZY/6C9tTcUv/KNAE5leyrD4IKbnV4PnbrVhjq861it/zRQW
 cFpWQszZyWRwNPWUUz7ejmm9lAwPbr8xWT4qMSA43VKQ7ZCeTQJ4TC8kjqtcbw41SjkjrcTG
 wF52zFO4bOWyovVAPncvV9eGA/vtnd3xEZXQiSt91kBSqK28yjxAqK/c3G6i7IX2rg6pzgqh
 hiH3/1qM2M/LSuqAv0Rwrt/k+pZXE+B4Ud42hwmMr0TfhNxG+X7YKvjKC+SjPjqp0CaztQ0H
 nsDLSLElVROxCd9m8CAUuHplgmR3seYCOrT4jriMFBtKNPtj2EE4DNV4s7k0Zy+6iRQ8G8ng
 QjsSqYJx8iAR8JRB7Gm2rQOMv8lSRdjva++GT0VLXtHULdlzg8VjDnFZ3lfz5PWEOeIMk7Rj
 trjv82EZtrhLuLjHRCaG50OOm0hwPSk1J64R8O3HjSLdertmw7eyAYOo4RuWJguYMg5DRnBk
 WkRwrSuCn7UG+qVWZeKEsFKFOkynOs3pVbcbq1pxbhk3TRWCGRU5JolI4ohy/7JV1TVbjiDI
 HP/aVnm6NC8of26P40Pg8EdAhajZnHHjA7FrJXsy3cyIGqvg9os4rNkUWmrCfLLsZDHD8FnU
 mDW4+i+XlNFUPUYMrIKi9joBhu18ssf5i5Q=
In-Reply-To: <CAGsJ_4wWEdxk0qNV89bL0zeGaXUBb7h92mdNeRCgcUCY5C84ww@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

On 3/17/24 16:48, Barry Song wrote:
> On Mon, Mar 18, 2024 at 7:13 AM Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> Hi,
>>
>> On Sat, Mar 02, 2024 at 08:27:45AM +1300, Barry Song wrote:
>> [ ... ]
>>> @@ -152,8 +165,17 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
>>>                        ret = -ENOSPC;
>>>                        goto out;
>>>                }
>>> -             scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen,
>>> -                                      1);
>>> +             if (dst == scratch->dst) {
>>> +                     scatterwalk_map_and_copy(scratch->dst, req->dst, 0,
>>> +                                              req->dlen, 1);
>>> +             } else {
>>> +                     int nr_pages = DIV_ROUND_UP(req->dst->offset + req->dlen, PAGE_SIZE);
>>> +                     int i;
>>> +                     struct page *dst_page = sg_page(req->dst);
>>> +
>>> +                     for (i = 0; i < nr_pages; i++)
>>> +                             flush_dcache_page(dst_page + i);
>>
>> flush_dcache_page() is an empty macro on some architectures
>> such as xtensa. This results in
> 
> Hi Guenter,
> 
> this is a bug of xtensa, could you test the patch:

Thanks for the update.

> https://lore.kernel.org/all/20240313045036.51065-1-21cnbao@gmail.com/
> 

That doesn't build for me.

   CC      arch/xtensa/kernel/asm-offsets.s
In file included from ./include/linux/highmem.h:8,
                  from ./include/linux/bvec.h:10,
                  from ./include/linux/blk_types.h:10,
                  from ./include/linux/writeback.h:13,
                  from ./include/linux/memcontrol.h:23,
                  from ./include/linux/swap.h:9,
                  from ./include/linux/suspend.h:5,
                  from arch/xtensa/kernel/asm-offsets.c:24:
./include/linux/cacheflush.h:9:5: error: "ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE" is not defined, evaluates to 0 [-Werror=undef]
     9 | #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE

A similar works for loongarch, so I don't know what is wrong.
Maybe some context patch is missing.

Guenter