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 A348B42885A; Mon, 29 Jun 2026 14:49:36 +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=1782744579; cv=none; b=qeO7J0dg7dRfXjE2IoccxPhy1ICriPhh2C2XX8+ysYJh0AoD6QsmVfkJfrjInmw3rbMcFjmNCo2VO2Xd9IAOXqTRq+2yVi+NbimP89DXSV0XxkzZe7Sf1UutqnqdAlZW+tacFCRmyXUhgx5ESEfWGHUAr9DiyiuLX5wIZK6pOR8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782744579; c=relaxed/simple; bh=ZaOKcFEgM2Ja04T+mFLDag/PCMCGRR9Ia/djkv3OPRA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TqRZzcuq+7nJVSRKXxVvwzaQXxzyAYjYChWDwgwRsYy62cxxmsEOZLzzsqcuxdypixzvJhx8aqZ729T5VTmC9A7h7ufcRY0ktgtLdBBwpRVvge7fT/nAJ5KqbjSXkfzM8EtqERB1Qe0z+ypcdUGW2U1C7QUJIZ0w4kIKr5MU4fA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=L9NuB6Qw; 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="L9NuB6Qw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 354511F00A3A; Mon, 29 Jun 2026 14:49:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782744576; bh=jf02Ij8O80K2A7ATECAqkrfhafLEEQ+h7n6pFX7YXCo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=L9NuB6Qwn+GuWe+S0bSEWS5lP/9JluIjXtyezwZmrVqdJhpwrre577CuWhH9pIF5I EgTUy/7NXimwhPPyophout9wNiSvN4ZjuVBRizCk/ELTPd9cEMYABojmHBrvesQ3HE KpCKaVFZkhX2gCNcaEfYqJQhhQQ2ZGKNEsZW/odAUP2tFyEVUOYC/8Bp2usDJVuTI1 1k3RkNx1fyrcXd4VJvpGfr5hyDxcn3GUwqDZtcmhxjqRZm0qypctwOLRCSUSuSuqDG 1DWdkOXAEMm2nCaJw+ozaPahHX2cvbFa8YtKDxIuh8Bt94xCQuP3O30wvu5tWyb0zX VZaSNd0x9zb7g== From: SJ Park To: Andrew Morton Cc: Ruslan Valiyev , SJ Park , Shuah Khan , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 2/2] selftests/damon/sysfs_refresh: test kdamond refresh_ms Date: Mon, 29 Jun 2026 07:49:26 -0700 Message-ID: <20260629144927.134237-3-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260629144927.134237-1-sj@kernel.org> References: <20260629144927.134237-1-sj@kernel.org> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Ruslan Valiyev Writing a non-zero value to a kdamond's 'refresh_ms' sysfs file should make DAMON periodically update the read-only sysfs files on its own, without the user writing update keywords such as 'update_schemes_stats' to the 'state' file. This behavior has no test coverage. Add a test that starts a kdamond with refresh_ms set and a 'stat' scheme whose default access pattern matches every monitored region, then polls the scheme's 'nr_tried' stats file directly, without requesting an update. The value can become non-zero only via the periodic refresh, so the test confirms refresh_ms works; with refresh_ms disabled the stat stays zero and the test fails. Link: https://lore.kernel.org/20260602131217.2210912-3-linuxoid@gmail.com Signed-off-by: Ruslan Valiyev Cc: Shuah Khan Reviewed-by: SJ Park Signed-off-by: SJ Park --- tools/testing/selftests/damon/Makefile | 1 + .../testing/selftests/damon/sysfs_refresh.py | 75 +++++++++++++++++++ 2 files changed, 76 insertions(+) create mode 100755 tools/testing/selftests/damon/sysfs_refresh.py diff --git a/tools/testing/selftests/damon/Makefile b/tools/testing/selftests/damon/Makefile index 2180c328a8252..ece244e5c5b95 100644 --- a/tools/testing/selftests/damon/Makefile +++ b/tools/testing/selftests/damon/Makefile @@ -13,6 +13,7 @@ TEST_PROGS += sysfs.py TEST_PROGS += sysfs_update_schemes_tried_regions_wss_estimation.py TEST_PROGS += damos_quota.py damos_quota_goal.py damos_apply_interval.py TEST_PROGS += damos_tried_regions.py damon_nr_regions.py +TEST_PROGS += sysfs_refresh.py TEST_PROGS += reclaim.sh lru_sort.sh # regression tests (reproducers of previously found bugs) diff --git a/tools/testing/selftests/damon/sysfs_refresh.py b/tools/testing/selftests/damon/sysfs_refresh.py new file mode 100755 index 0000000000000..012b7e8f509f5 --- /dev/null +++ b/tools/testing/selftests/damon/sysfs_refresh.py @@ -0,0 +1,75 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0 + +import os +import subprocess +import time + +import _damon_sysfs + +def main(): + # Continuously access a memory region for far longer than the test needs, + # so the kdamond always has a live target to monitor while we poll. + sz_region = 10 * 1024 * 1024 + proc = subprocess.Popen( + ['./access_memory', '1', '%d' % sz_region, '60000', 'repeat']) + + # A 'stat' scheme with the default (maximally wide) access pattern matches + # every monitored region, so its 'nr_tried' stat increases as the kdamond + # runs. refresh_ms should make DAMON update the schemes' stats files under + # sysfs on its own, without a manual 'update_schemes_stats' request. + kdamond = _damon_sysfs.Kdamond( + refresh_ms=100, + contexts=[_damon_sysfs.DamonCtx( + ops='vaddr', + targets=[_damon_sysfs.DamonTarget(pid=proc.pid)], + schemes=[_damon_sysfs.Damos(action='stat')], + )]) + kdamonds = _damon_sysfs.Kdamonds([kdamond]) + + err = kdamonds.start() + if err is not None: + # Kernels older than the refresh_ms feature have no such file; treat + # that as unsupported rather than a failure. + if not os.path.exists(os.path.join(kdamond.sysfs_dir(), 'refresh_ms')): + proc.terminate() + proc.wait() + print('kdamond has no refresh_ms file; skipping') + exit(_damon_sysfs.ksft_skip) + proc.terminate() + proc.wait() + print('kdamond start failed: %s' % err) + exit(1) + + scheme = kdamond.contexts[0].schemes[0] + nr_tried_path = os.path.join(scheme.sysfs_dir(), 'stats', 'nr_tried') + + try: + # Poll the stat file directly. We never request an update (e.g. + # 'update_schemes_stats'), so 'nr_tried' can become non-zero only + # through the periodic refresh that refresh_ms enables. + nr_tried = 0 + deadline = time.monotonic() + 10 + while time.monotonic() < deadline: + if proc.poll() is not None: + print('the access_memory target exited unexpectedly') + exit(1) + content, err = _damon_sysfs.read_file(nr_tried_path) + if err is not None: + print('reading %s failed: %s' % (nr_tried_path, err)) + exit(1) + nr_tried = int(content) + if nr_tried > 0: + break + time.sleep(0.1) + finally: + kdamonds.stop() + proc.terminate() + proc.wait() + + if nr_tried == 0: + print('refresh_ms did not auto-update the schemes stats') + exit(1) + +if __name__ == '__main__': + main() -- 2.47.3