From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794777450; b=HkSmaO1KxD03FZ9pIuOiX337895kI9146O+7ScaoG0UQIE/HfCc+ftSCFpuMnU3qjj7E 9QMAB5LsKwSPLwv0kxT+/KEL81G0mSKZDrU3wcLKdrdvWKIiwQEQbQqk5KagbLwUQDtwa ATfxS9QYvgwLLuoKHQVPbHpA3lm5N1X01kdeGWmQOZImaQFiWeqxV4rLPNmVTU4LnfY5D FD31sgOvSk7DhdvoCAqqfUIyqpPMfV0/4qmPA1OMANzp8r5qj76IHMrM254ItQMNnaxXN kgyrl/Xi9b00DsN55a0HFEe2F+daBjdZYyu9n5j8fcMmwnzN9TkOTZMiZRQVJLvGVHQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794777450; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=EE7GAzdHDxgyN97YRBQACDLzjUljmIUH3x5jpLG84+E=; b=b0D1W30BFpglUCMrw0Cc7rTRIGyEiuEoQogfcFteXBd+x2Ar3+z19h03ZQtN0nQGa+mx Kci8i83NuPWTB2lVPQ0ZTo6OW7wAKaAJYh5+dQDfGT5BQh1vx6OcOt7k6oIxtDz2dGW1t S2ftavk/I10VNxk1Fa9WzgdNPAO+bI7hjQzuzph66l9N6pTDg5mqNPZYFNtEcammGtb0x sqSqwg/g/VMa/IhoyluW7262Fq1m+UmYluPjVLtXoCRvZfpZs3P/EgqgOc41lpqINPk8W Smm7HBisUJurIkt55Sj7N63TyrPcCeWebj5bE9oKX2bDS7/1QrXpMmUS4qEwDxE5DoA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BwYVRuQ3; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C031A606A329 for ; Sun, 15 Nov 2026 21:17:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BwYVRuQ3 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66FDC1F000C5; Sun, 15 Nov 2026 21:17:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794777450; bh=EE7GAzdHDxgyN97YRBQACDLzjUljmIUH3x5jpLG84+E=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BwYVRuQ3+jmYVOnw/z8CebDR+LNz8kgr/CPQcAxMUOha8IjB4i7VZajFRhyWLuqtB q9TepgLNsgS7Jb4tOeJm8PDeo61l/KRfxdxIFVOVf4TsQUd9Vm5tQ1N1UQfdsazrUb iPNyRpeVOgme/P5NUsn0f+MHjoY3Vc4rmKXQL15Td9oi77VU7OZhp13RYijWXWvmgn x/yMNpxtA4FfVnarTOOFCre6EWFUg1+3+RJUV9tRXPA4etZk8oMMVgtWBitvbsMVJm vlgvvGm8nSN1aE0SBLNCls2Zo4ae144ELao1ZMKnh7+4aS37Q3hb6oQf1C/ty7OfHN cmpRAt0jGMkLw== From: SJ Park To: sashiko-bot@kernel.org Cc: SJ Park , "Andrew Morton" , damon@lists.linux.dev, linux-mm@kvack.org Subject: Re: [RFC PATCH 02/27] mm/damon/core: implement data attribute report queue Date: Sun, 15 Nov 2026 13:17:22 -0800 Message-ID: <20261115211723.101033-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: X-Mailing-List: damon@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Sun, 15 Nov 2026 20:41:23 +0000 sashiko-bot@kernel.org wrote: > Thank you for your contribution! Sashiko AI review found 3 potential > issues to consider: > - [Medium] mm/damon: damon_init() leaks damon_region_cache on queue > alloc failure > - [Low] mm/damon: missing static qualifier on damon_report_queue in > core.c > - [Low] mm/damon: struct damon_report_queue comment documents head not > nr_reports > -- > > commit 10a61bc9bab6e48534e4a8552380aecaccbee97a > Author: SJ Park > > mm/damon/core: implement data attribute report queue > > This commit adds an internal damon_report_queue structure, allocates its > buffer for up to 1,000 reports in damon_init(), and checks that buffer in > damon_initialized(). > > > diff --git a/mm/damon/core.c b/mm/damon/core.c > > index 0a056949604f9..3f87a7eec442e 100644 > > --- a/mm/damon/core.c > > +++ b/mm/damon/core.c > > @@ -2334,6 +2334,25 @@ int damos_walk(struct damon_ctx *ctx, struct damos_walk_control *control) > > return 0; > > } > > > > +/* > > + * struct damon_report_queue - &struct damon_report queue. > > + * > > + * @lock: Represent if this queue is being used by someone. > > + * @head: Head of the queue. > > + * @tail: Tail of the queue. > > + * @size: Size of the queue. > > + * @reports: Array of &struct damon_report. > > + */ > > +struct damon_report_queue { > > + atomic_t lock; > > + unsigned int tail; > > + unsigned int size; > > + unsigned int nr_reports; > > + struct damon_report *reports; > > +}; > > [Severity: Low] > The comment above struct damon_report_queue documents @head, whereas the > struct defines nr_reports instead. Nice catch. I will remove the comment for @head and add a comment for @nr_reports. > > > + > > +struct damon_report_queue damon_report_queue; > > [Severity: Low] > Should damon_report_queue be marked static? struct damon_report_queue is > private to mm/damon/core.c, so leaving damon_report_queue non-static > exports it into the global namespace and triggers sparse and W=1 missing > variable declaration warnings. Good suggestion, I will mark it as static. > > > + > > /* > > * Reset the aggregated monitoring results ('nr_accesses' of each region). > > */ > > @@ -4308,7 +4327,7 @@ void damon_update_region_access_rate(struct damon_region *r, bool accessed) > > */ > > bool damon_initialized(void) > > { > > - return damon_region_cache != NULL; > > + return damon_region_cache && damon_report_queue.reports; > > } > > > > static int __init damon_init(void) > > @@ -4319,6 +4338,14 @@ static int __init damon_init(void) > > return -ENOMEM; > > } > > > > + damon_report_queue.size = 1000; > > + damon_report_queue.reports = kmalloc_objs(*damon_report_queue.reports, > > + 1000, GFP_KERNEL); > > + if (!damon_report_queue.reports) { > > + pr_err("report queue alloc fail\n"); > > + return -ENOMEM; > > + } > > [Severity: Medium] > Does this error path leak damon_region_cache when kmalloc_objs() fails? > Destroying damon_region_cache and resetting it (along with > damon_report_queue.size) before returning -ENOMEM would avoid leaking the > slab cache and leaving partially initialized state. Good suggestion. I will do destroy damon_region_cache. > > -- > Sashiko AI review ยท https://sashiko.dev/#/patchset/20261115202849.99134-1-sj@kernel.org?part=2 > Thanks, SJ