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Fri, 27 Mar 2026 19:26:53 -0700 (PDT) From: Liew Rui Yan To: sj@kernel.org Cc: aethernet65535@gmail.com, damon@lists.linux.dev, linux-mm@kvack.org Subject: Re: [PATCH] mm/damon: validate addr_unit to be power of 2 Date: Sat, 28 Mar 2026 10:26:51 +0800 Message-ID: <20260328022651.41744-1-aethernet65535@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260328001405.4253-1-sj@kernel.org> References: <20260328001405.4253-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam12 X-Stat-Signature: 4zaazpqzk3q3sf7zi3jcwdb8d3bx7imo X-Rspamd-Queue-Id: 2A0E240005 X-Rspam-User: X-HE-Tag: 1774664814-175872 X-HE-Meta: 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 r9xQEUuh IQdeHZwVzbl564g9+4X9usohJjTaq5nYxLz+zo8vjX1mYwRxg2BBjHi4DdEjA3OA6culW Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi SeongJae, > It would be better to not terminate. But not a big deal. Users could be wary > of the consequence, as long as it is well documented. > > From my perspective, therefore, code maintenance is more important. If we can > make DAMON not terminated by invalid user inputs caused damon_commit_ctx() but > it introduces a significant amount of code complexity, I don't think that's a > good deal. Thank you so much for the thoughtful response! I completely agree that code maintainability should be the priority and we should avoid unnecessary complexity. Just to make sure I captured the full context, in my earlier follow-ups [1][2] (in case they got folded in your email client): - Does the current kdamond termination on invalid user input align with your design goal mentioned in [3] (stopping only for "internal errors")? - Would a lightweight fix be acceptable? For example, performing validation at the very beginning of damon_commit_ctx(), and returning -EINVAL before setting 'maybe_corrupted' to true. Since no modifications to 'dst' would have occurred, kdamond could safely continue with its old configuration. Thank you again for your time, and guidance. :> [1] https://lore.kernel.org/20260327064517.68131-1-aethernet65535@gmail.com [2] https://lore.kernel.org/20260327121009.38374-1-aethernet65535@gmail.com [3] https://lore.kernel.org/20260319151528.86490-1-sj@kernel.org Best regards, Rui Yan