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Mon, 15 Sep 2025 04:07:52 -0700 (PDT) Message-ID: <328b3f8f-cca7-4d8f-9335-24341b40b2d5@bytedance.com> Date: Mon, 15 Sep 2025 19:07:47 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [External] Re: [PATCH] vduse: Use fixed 4KB bounce pages for arm64 64KB page size To: Jason Wang Cc: mst@redhat.com, xuanzhuo@linux.alibaba.com, eperezma@redhat.com, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, xieyongji@bytedance.com References: <20250915073429.54027-1-sheng.zhao@bytedance.com> Content-Language: en-US From: Sheng Zhao In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 在 2025/9/15 16:21, Jason Wang 写道: > On Mon, Sep 15, 2025 at 3:34 PM wrote: >> >> From: Sheng Zhao >> >> The allocation granularity of bounce pages is PAGE_SIZE. This may cause >> even small IO requests to occupy an entire bounce page exclusively. > > This sounds more like an issue of the IOVA allocating that use the > wrong granular? > Sorry, the previous email has a slight formatting issue. The granularity of the IOVA allocator is customized during the initialization of the vduse domain, and this value is also modified in this commit. Thanks >> The >> kind of memory waste will be more significant on arm64 with 64KB pages. >> >> So, optimize it by using fixed 4KB bounce pages. >> >> Signed-off-by: Sheng Zhao > > Thanks >