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 CDA8A430BB5; Sun, 1 Mar 2026 16:33:46 +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=1772382826; cv=none; b=m2uW2YcbE/XxbMyPoJQQYEh4sok+m0rp5js9+QOYg+Jg0hCgDq4DWduqx9TtSohwyc2ASZ7S8T+oet2zHJtCbQhoNTFafeLm4ZNn3ZQv1fnvSQqe6F+UclP2DzQW+WWpzbfYlhKMi+Kc38/AWD37XsNjzQ09WyUfMv3MCA7Lp5A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772382826; c=relaxed/simple; bh=mSj6jEZ06Ohm/vWYhM3VYr9y1jAdM9wKNerjpfHg+c4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uebolQGHgZ8aDE/FtGbphRqjs+XuGjStKwve8lRGox8ans1/1yz9KLP7s7AkmKE7KLoh/Z5YLgw4RS/XaoxPo/n/PJnmwoM5WcofT9rN0nbCVqKQtS22bdyQ6XQR0k7vh7xx4oXonTl4ZLgDTk2p8PubCvPzdBtz1AaeTIb50OA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YoEMPbGX; 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="YoEMPbGX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 997E5C116C6; Sun, 1 Mar 2026 16:33:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772382826; bh=mSj6jEZ06Ohm/vWYhM3VYr9y1jAdM9wKNerjpfHg+c4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YoEMPbGXEoKrvcD3G+BXlmmxRvenZp48x1mkjangqOwx1mx0QpYwv6Putkn81vFvv 2HQHsAL+YyxQDbR+dOrl0Gori1yGuVLoOelDno0SNrHGsTQi3lIwTTf+ZsZXa/l11i esMLqHcS7FuqOXrvCEGPoVxyXqHwXnbCMzZTR1v0LfERXfMBKcZMm6Dc52rFMvD/G7 24she6UB40n0SRA0ZP32mjHQQ4Ci0Z4lHBHQfNUV0Ykpw359QtghnwyhVNgIRb2Rlo hnGwZzXXOKtEsr3T9trA35r3RhSw6vslv6F3LAtsFULITsC8fOLNAbupM8oI2tkp1e x0UvmXB3p0WDQ== From: SeongJae Park To: SeongJae Park Cc: Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH 02/10] mm/damon/core: add damon_new_region() debug_sanity check Date: Sun, 1 Mar 2026 08:33:36 -0800 Message-ID: <20260301163337.92637-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260221193629.19332-3-sj@kernel.org> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Sat, 21 Feb 2026 11:36:19 -0800 SeongJae Park wrote: > damon_new_region() is supposed to be called with only valid address > range arguments. Do the check under DAMON_DEBUG_SANITY. > > Signed-off-by: SeongJae Park > --- > mm/damon/core.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/mm/damon/core.c b/mm/damon/core.c > index 602b85ef23597..a7f5748c1fe17 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c > @@ -109,6 +109,22 @@ int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id) > return err; > } > > +#ifdef CONFIG_DAMON_DEBUG_SANITY > +static void damon_verify_new_region(unsigned long start, unsigned long end) > +{ > + I'll remove the above unnecessary new line in the next spin. > + if (start < end) > + return; > + pr_err("damon_new_region() s called with start %lu >= end %lu!\n", > + start, end); > + WARN_ONCE(); > +} > +#else > +static void damon_verify_new_region(unsigned long start, unsigned long end) > +{ > +} > +#endif > + > /* > * Construct a damon_region struct > * > @@ -122,6 +138,8 @@ struct damon_region *damon_new_region(unsigned long start, unsigned long end) > if (!region) > return NULL; > > + damon_verify_new_region(start, end); > + The verification may better to be made before the above region allocation. I'll move it to the beginning of this function in the next spin. > region->ar.start = start; > region->ar.end = end; > region->nr_accesses = 0; > -- > 2.47.3 Thanks, SJ