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Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1s5Gm5-000000027Oc-3RIv; Fri, 10 May 2024 03:18:22 +0000 Date: Fri, 10 May 2024 04:18:21 +0100 From: Matthew Wilcox To: Zhaoyang Huang Cc: "zhaoyang.huang" , Andrew Morton , Jens Axboe , Tejun Heo , Josef Bacik , Baolin Wang , linux-mm@kvack.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, steve.kang@unisoc.com Subject: Re: [RFC PATCH 2/2] mm: introduce budgt control in readahead Message-ID: References: <20240509023937.1090421-1-zhaoyang.huang@unisoc.com> <20240509023937.1090421-3-zhaoyang.huang@unisoc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: A194F100004 X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: fy8kk3zhmxtuoi3s9jty54co6noiae8b X-HE-Tag: 1715311113-291203 X-HE-Meta: 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 xUhIfn4u 2Cxl6l2zvG/mtZX2N/ZpCfIt7B/+iABE4SGbUDucB1p+ExWJdyXNXMFER3daz5IuXj21yoppe6uvtpbfyOt5/vG0oTEtwWh6IlxFalP9nUE5ECywllQoCYMUUOyoHc7+Tdh9URliNKO3bH7s= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, May 10, 2024 at 10:43:20AM +0800, Zhaoyang Huang wrote: > Thanks for the prompt. I did some basic research on soft RAID and > wonder if applying the bps limit on /dev/md0 like below could make > this work. No. Look at btrfs' raid support, for example. it doesn't use md0. > I didn't find information about 'RAID internally'. Could we set the > limit on the root device(the one used for mount) to manage the whole > partition without caring about where the bio finally goes? Or ask the > user to decide if to use by making sure the device they apply will not > do RAID? No.