From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38E659475 for ; Sun, 3 Aug 2025 18:01:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754244071; cv=none; b=KzFrTyFi8ExF9oklmV8v494bBOVCQgOc/OzEfZ882TOVYeNntrxF74iAv/csaNyKXFg/9pyXCScRQ4GwqZe7EnmWtjrpKuf0a2U/GVNFjvJgnoHhMSbb4WqmSeS0iCbKBbZScU3hWPenzvb13KToQQ7SXE7ufP3K0zedEmZ2ezI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754244071; c=relaxed/simple; bh=1+srFKL5LqQUBE4GwEXD1v1Xs+lZWuUYAffO+amh/XM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=QCj/lijJRg12WY/fdM4CuBVLuntDb5EYLI2hgG33EQMDziHEn1lDUmzexjnFSLnh49i8wqjE3Palmr/oTMRnM2j5FEGp5ineYRz9jn+0wP5If9OzBIU83GiH0RQAY6e5SVBFemUVLGcykDKig6xxAG66ietxo3rxAVTjgtwfBTw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TXUhQcT+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TXUhQcT+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AC25C4CEEB; Sun, 3 Aug 2025 18:01:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754244070; bh=1+srFKL5LqQUBE4GwEXD1v1Xs+lZWuUYAffO+amh/XM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TXUhQcT+ugcm5eT1xOc9y5+zk9JC/OFlH4LG6kssruOF4S/UiB6QcmQSbH/bAfimq QcLBkrzzDmQXE3o73LC4M0AG2r9gL+2CTY/Xylgf50MCoZm1s6z5cfxB7bfGrkRsH7 ScsiNM/oKRN4YIsWDbV08YQUw7z3py4EVvQ+unh5rYxeRkHcQeZvMhofRhB5iAm+M6 FPycvMxT2hz0SA/UFj+G2V3oy4DoJk7S+J3Wbuki/8ah0pAbcgWktVoZ7u4sKDCmYH 7rjtTOJKDbMQJx7PHujyg2OoAzQsCQwIJttYTJd5s11Rk+9/93CbmRkAVe3n4EPygU fAKv4qNwE3O8Q== From: SeongJae Park To: Akinobu Mita Cc: SeongJae Park , damon@lists.linux.dev, Bijan Tabatabai Subject: Re: [PATCH] mm/damon/vaddr: avoid unnecessary migration between target nodes Date: Sun, 3 Aug 2025 11:01:07 -0700 Message-Id: <20250803180107.56197-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250803130028.162537-1-akinobu.mita@gmail.com> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hello Akinobu, On Sun, 3 Aug 2025 22:00:28 +0900 Akinobu Mita wrote: > This change avoids unnecessary migration by checking if the folio to which > the migration is applied is already located in one of the target nodes. Each folio will get a single target node among the target nodes, based on the weights of targets and the virtual address of the folio. So skipping the migration because the folio is on one of target nodes can result in wrong behavior (not doing required migrations)? Also, a similar purpose optimization was already made by Bijan. I guess you aware of that and therefore Cc-ed Bijan. Could you further share differences between this and Bijan's one, and measured additional performance gain from this patch, if you have? [1] https://lkml.kernel.org/r/20250725163300.4602-1-bijan311@gmail.com Thanks, SJ [...]