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 A790F15C9D for ; Tue, 22 Nov 2022 19:48:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8418C433D6; Tue, 22 Nov 2022 19:48:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669146518; bh=fELDYP7X7g2hQl01HL1seDQ0enwlGxaSh2Vjv+ZYToU=; h=From:To:Cc:Subject:Date:From; b=d9awUBACiXT6NtF2V4ad/eJjEaQCigkXO/j1aQoYsuFW6RdPlhNvCz352QKphf6uv YeHKeIHQLBktbxEvc0HOp+LzekGhy5IIrfe6vuqQZ0djQb/haE5Rq+vjd2jxYOP3AB bzUfe4vQLX7dcyuwlXhqofokrNoUPDH4XD832fhZ31mJAv3yjMpbSoctQF0+vJNA5a pJLEyOhcaZTvflI94IT8T66up2b/V6KJpR60+xl9uz4atP+qUNuq9fJzOYRWnXvWX5 yXFFaeNg50ZldZGB7nOgFqPk1bBpqglkmqfDflyfWghPpY5OZ37nRSKAcdsfSWB67p TOTO1D6eWMa7Q== From: SeongJae Park To: akpm@linux-foundation.org Cc: damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, SeongJae Park , stable@vger.kernel.org Subject: [PATCH mm-hotfixes-unstable] mm/damon/sysfs: fix wrong empty schemes assumption under online tuning in damon_sysfs_set_schemes() Date: Tue, 22 Nov 2022 19:48:31 +0000 Message-Id: <20221122194831.3472-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Commit da87878010e5 ("mm/damon/sysfs: support online inputs update") made 'damon_sysfs_set_schemes()' to be called for running DAMON context, which could have schemes. In the case, DAMON sysfs interface is supposed to update, remove, or add schemes to reflect the sysfs files. However, the code is assuming the DAMON context wouldn't have schemes at all, and therefore creates and adds new schemes. As a result, the code doesn't work as intended for online schemes tuning and could have more than expected memory footprint. The schemes are all in the DAMON context, so it doesn't leak the memory, though. Remove the wrong asssumption (the DAMON context wouldn't have schemes) in 'damon_sysfs_set_schemes()' to fix the bug. Fixes: da87878010e5 ("mm/damon/sysfs: support online inputs update") Cc: # 5.19.y Signed-off-by: SeongJae Park --- mm/damon/sysfs.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 44 insertions(+), 2 deletions(-) diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index 5ce403378c20..07e5f1bdf025 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -2283,12 +2283,54 @@ static struct damos *damon_sysfs_mk_scheme( &wmarks); } +static void damon_sysfs_update_scheme(struct damos *scheme, + struct damon_sysfs_scheme *sysfs_scheme) +{ + struct damon_sysfs_access_pattern *access_pattern = + sysfs_scheme->access_pattern; + struct damon_sysfs_quotas *sysfs_quotas = sysfs_scheme->quotas; + struct damon_sysfs_weights *sysfs_weights = sysfs_quotas->weights; + struct damon_sysfs_watermarks *sysfs_wmarks = sysfs_scheme->watermarks; + + scheme->pattern.min_sz_region = access_pattern->sz->min; + scheme->pattern.max_sz_region = access_pattern->sz->max; + scheme->pattern.min_nr_accesses = access_pattern->nr_accesses->min; + scheme->pattern.max_nr_accesses = access_pattern->nr_accesses->max; + scheme->pattern.min_age_region = access_pattern->age->min; + scheme->pattern.max_age_region = access_pattern->age->max; + + scheme->action = sysfs_scheme->action; + + scheme->quota.ms = sysfs_quotas->ms; + scheme->quota.sz = sysfs_quotas->sz; + scheme->quota.reset_interval = sysfs_quotas->reset_interval_ms; + scheme->quota.weight_sz = sysfs_weights->sz; + scheme->quota.weight_nr_accesses = sysfs_weights->nr_accesses; + scheme->quota.weight_age = sysfs_weights->age; + + scheme->wmarks.metric = sysfs_wmarks->metric; + scheme->wmarks.interval = sysfs_wmarks->interval_us; + scheme->wmarks.high = sysfs_wmarks->high; + scheme->wmarks.mid = sysfs_wmarks->mid; + scheme->wmarks.low = sysfs_wmarks->low; +} + static int damon_sysfs_set_schemes(struct damon_ctx *ctx, struct damon_sysfs_schemes *sysfs_schemes) { - int i; + struct damos *scheme, *next; + int i = 0; + + damon_for_each_scheme_safe(scheme, next, ctx) { + if (i < sysfs_schemes->nr) + damon_sysfs_update_scheme(scheme, + sysfs_schemes->schemes_arr[i]); + else + damon_destroy_scheme(scheme); + i++; + } - for (i = 0; i < sysfs_schemes->nr; i++) { + for (; i < sysfs_schemes->nr; i++) { struct damos *scheme, *next; scheme = damon_sysfs_mk_scheme(sysfs_schemes->schemes_arr[i]); -- 2.25.1