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 ADE783A1A46 for ; Thu, 26 Feb 2026 10:01:08 +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=1772100068; cv=none; b=o3SH4yHzEI9yBeHRNLcseWVoGxR1g/OjsqUAh1N1jPRiG9oM4/gA11VEQ/V4Oz2/dv7lyxn2LaPF/ijJ5C5y/TpDLjmR+vI1lckPJR0SznGbLi9qWZa8glYgWeV4ONviK89UbIPQOMLaARkF1Cm7XI2P3w1EzZrk3b2peZN+3ws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772100068; c=relaxed/simple; bh=HEuk0s9GZMJPl2JuT5lCr+YlmbdmuejV1eS3nm6JHko=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BwTUF/lpIRroe7KCwwqsbQwAqMoRZEJrAlyrW+WoiejcU4tKm2aytt2yzJBRdRqVLUnok/ITlJGrdjAAM0b+AugSkbN5lcKgTBk50OuBCnEei1kjCPWWg7Ksp9J6+CfYoXxs+lEdjMLj73CQNYZus6qaiCoEzsgcET68xdxnIYg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A+trAdNZ; 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="A+trAdNZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B113EC19422; Thu, 26 Feb 2026 10:01:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772100068; bh=HEuk0s9GZMJPl2JuT5lCr+YlmbdmuejV1eS3nm6JHko=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=A+trAdNZEwYhjQmBGJfZ6Vj8jtvHi8ZvdtrkS1EA5HCl3CZrzj0NNMQJ4hA/Xlo/x g83xdKCdI7meSzm/0Ceq4+qRO/SdSW1dAZGW4UBLLA5S1crR6Bwahm82LQdYEB9T4c MT3zIytjl20iBm5JJO3mgpIS+RvJcAu6nL2y0CDtbkQTcs6jfC7RqEm5TFTuUzFSBh WIBbTUmLvmi7ul1fa9xOUF6EO64uv6v+3GrDp9dcO6NgLkPFTyEZCxovNVsWhAuwry ekV9Y/Y9iAKPxpV9aTZ1n9UEJ1y24RC+dihZP7p37F3Bh/xuIPpF94AdbUqbMXpPZV SdhhXDvwSkrkg== Message-ID: <811c5456-44c9-4b90-bace-caba6cb6f972@kernel.org> Date: Thu, 26 Feb 2026 11:01:04 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: khugepaged: simplify scanning progress in pmd To: Vernon Yang Cc: akpm@linux-foundation.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, richard.weiyang@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vernon Yang References: <20260226081313.53518-1-vernon2gm@gmail.com> <06ff4738-e81a-49ab-9204-74a6829d8d8b@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit >> >> static int khugepaged_has_work(void) >> @@ -2545,13 +2555,14 @@ static int khugepaged_wait_event(void) >> >> static void khugepaged_do_scan(struct collapse_control *cc) >> { >> - unsigned int progress = 0, pass_through_head = 0; >> - unsigned int pages = READ_ONCE(khugepaged_pages_to_scan); >> + const unsigned int progress_max = READ_ONCE(khugepaged_pages_to_scan); >> + unsigned int pass_through_head = 0; >> bool wait = true; >> enum scan_result result = SCAN_SUCCEED; >> >> lru_add_drain_all(); >> >> + cc->progress = 0; > > madvise(MADV_COLLAPSE) is missing the initialization of "cc->progress" > because "cc = kmalloc_obj(*cc)". We need to manually initialize it in > madvise_collapse(). Right, although it wouldn't matter right now, because nobody would be reading the value. It's really weird that cc is not simply completely zeroed out in madvise_collapse(). -- Cheers, David