From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7CC8B51CF54; Thu, 15 Oct 2026 14:05:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792073110; cv=none; b=AdKovjFanHzA/X253Iv2CMT3xSnGres4cVhFSfqSALCHG/16Msxd1VNwg/bWnXivp6iBhdX6zV/Bk3mrvw0QG0EgQRBTI9tZQ04VF1Ss8hdSqWjfFvNu1Xc3lsMXu48IWFg4k6805VBOEqPUX2MLBOn4iwJossFZaUHvvsqU2zw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792073110; c=relaxed/simple; bh=+unhxejwLGoCorOIr4ni9FmFAe8EO42zECrx8uh0Ny4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JkwwziWA2sX3E6zwmOnjZSZ95IoHCtA9jhbfUHa14fpyRC/oBT98BcNmU9LLxsbVfpv2kaJx5vT9niqM2A762FUK0KUT/v0fVlHElxVCyQsnNMj4cBSvgqo4jFRbFXcuQ7JujF7sf87/brS4NCArhs3QX8kJhRIgUbLAzdRL9Fc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Tnslj58V; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Tnslj58V" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCE891F000C6; Thu, 15 Oct 2026 14:05:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792073109; bh=5ocp4Et+sK/z58kpgz7L+Txb0eSLyo+tHlzKReRnPCk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Tnslj58VcWVpVH2J5Em3kGZqb2Lv4pzwZPtldGD6fzcLiFwsjPKtWdAsQZkqfue0H q00IUB0TkvRYKIgWrzOBh40ZHTyE+yumCC83Kh3a4i23PUYwQmkyu8sKarYwII/AUk Wj0yW11JgnqZUMdpMcycBUwI5wglVWWoPVhckHTzt2zx5zNbFmw0QzlNehMyhnKHk3 vOiFHoRdFXUX4NJ2FmDrVjLlWrEoiAYXF+sk2KbRbW2sqHj0q0jFtz2K/lN9Lh6tCw 5atdSz442mcHmcBok5QP2DHIuOkz8reEfp/1+cIArP7LybmAgo0VsSmSZRAblYCi7g zCWLXW/5CPIUQ== From: SJ Park To: Aveline Noir Cc: SJ Park , Andrew Morton , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [BUG] DAMON sysfs: failed update clears tried_regions snapshot Date: Thu, 15 Oct 2026 07:05:01 -0700 Message-ID: <20261015140502.87975-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi Avelin, On Thu, 15 Oct 2026 07:22:38 -0400 Aveline Noir wrote: > Hi, > > On mm-new commit ad9f2d463666, requesting > update_schemes_tried_regions after stopping a kdamond returns > -ECANCELED and clears the previous tried_regions snapshot. The final > result collected before "off" is then lost. Could you further share your use case that this behavior becomes a real problem? Also, have you tried bisecting this to find from when this behavior was introduced? If so, could you share the commit that introduced this behavior? THanks, SJ [...]