Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <e38e8525-3e9c-8925-2160-228875183f28@bytedance.com>
Date:   Wed, 12 Jul 2023 17:36:20 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0)
 Gecko/20100101 Thunderbird/102.13.0
Subject: Re: [PATCH v2] mm: kfence: allocate kfence_metadata at runtime
To:     Alexander Potapenko <glider@google.com>
Cc:     elver@google.com, dvyukov@google.com, akpm@linux-foundation.org,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, muchun.song@linux.dev,
        Peng Zhang <zhangpeng.00@bytedance.com>
References: <20230712081616.45177-1-zhangpeng.00@bytedance.com>
 <CAG_fn=Vj+rqkz0_3kvBoBVoxET10KV-zoD=YtJmCfsA8YEMemg@mail.gmail.com>
From:   Peng Zhang <zhangpeng.00@bytedance.com>
In-Reply-To: <CAG_fn=Vj+rqkz0_3kvBoBVoxET10KV-zoD=YtJmCfsA8YEMemg@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


在 2023/7/12 17:30, Alexander Potapenko 写道:
>> Below is the numbers obtained in qemu (with default 256 objects).
>> before: Memory: 8134692K/8388080K available (3668K bss)
>> after: Memory: 8136740K/8388080K available (1620K bss)
>> More than expected, it saves 2MB memory. It can be seen that the size
>> of the .bss section has changed, possibly because it affects the linker.
> 
> The size of .bss should only change by ~288K. Perhaps it has crossed
> the alignment boundary for .bss, but this effect cannot be guaranteed
> and does not depend exclusively on this patch.
> I suggest that you omit these lines from the patch description, as
> they may confuse the readers.
Ok, I'll revise it to avoid confusion.