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 4643586353 for ; Fri, 6 Feb 2026 08:46:43 +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=1770367604; cv=none; b=T0o2tUI0pBpjvBotHYFUx3GnzLQcclDNy4y1afgd6hCRMBmZDXN8cGWLple0yhCzX2OnUqPW+/MvASX8RM3JJ8lRGLgT2fFGIifw6XizBNVaVh50LTMsCKj5bdVqEOZDo8cB05xUGHlw2ZBDQa8BmSgODamdAWQ5eyCMIMwkHWw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770367604; c=relaxed/simple; bh=vchmqJmb2mGDzQ5x5W+qQCMF+BxTNhOa/z4vEqJc8JY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=VLVzb5j/aL0PvuOoNOtyKajqgUhCAXSiQDwa9jHCxAOE4oBsp7x3C1vcnD8oqhOgVg34aYe/bll0OgkhusMDB/i2va+WLQyS4dg79u9UZq2zVCB1T8dlNUqlra5ycM1nxLW7/ea2Nd66x+BWDfQTFzd6Hb8v+PS2Vt0DI9FlQLk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cd2IjknD; 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="Cd2IjknD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0B7DC116C6; Fri, 6 Feb 2026 08:46:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770367603; bh=vchmqJmb2mGDzQ5x5W+qQCMF+BxTNhOa/z4vEqJc8JY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Cd2IjknDbdngmTYRAHlMyH9MekbEjkFVmozUJp/COGZI19pcTJnY0rNhFUfqrqndS UBJKaYmS2RiZNDQWvIZ4G7L42zymEiKNkxbyLiJ0hlPvCxtIwWvJcOkw4KMMCb2Kd8 +4VzoOWTRqe4RGKPudwWWwDj1SppAG2VMtab3T0f4bR9fOemtAPvczwUUiiMbCYuC/ ilC3bgaqb34EUYyN/lcVUqec/vp4tVz36nvAmgqBOEWnW85zTEXU1PBQkLDBvlnZ4C eEfXdrx6qETuZz1hbBxD5p4CnHBtyg0snmRCpUQBTDISlHWVjhbrXNcISMm1ndFd6p 8DVOWEghBCFog== Message-ID: Date: Fri, 6 Feb 2026 09:46:40 +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: ksm: initialize rmap values directly and make them const To: xu.xin16@zte.com.cn Cc: akpm@linux-foundation.org, chengming.zhou@linux.dev, hughd@google.com, wang.yaxin@zte.com.cn, yang.yang29@zte.com.cn, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260206163850402hEblYPDgLSG4M7CT1ju2G@zte.com.cn> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/6/26 09:38, xu.xin16@zte.com.cn wrote: >>> Considering that commit 06fbd555dea8 ("ksm: optimize rmap_walk_ksm by passing >>> a suitable addressrange") seems to have already been merged, this new patch is >>> proposed to address the issue raised by David at: >>> >>> https://lore.kernel.org/all/ba03780a-fd65-4a03-97de-bc0905106260@kernel.org/ >>> >>> This initialize rmap values (addr, pgoff_start, pgoff_end) directly and >>> make them const to make code more robust. Besides, since KSM folios are always >>> order-0, so folio_nr_pages(KSM folio) is always 1, so the line: >>> >>> "pgoff_end = pgoff_start + folio_nr_pages(folio) - 1;" >>> >>> becomes directly: >>> >>> "pgoff_end = pgoff_start;" >>> >>> The test reproducer of rmap_walk_ksm can be found at: >>> https://lore.kernel.org/all/20260206151424734QIyWL_pA-1QeJPbJlUxsO@zte.com.cn/ >> >> Thanks! >> >>> >>> Fixes: 06fbd555dea8 ("ksm: optimize rmap_walk_ksm by passing a suitable addressrange") >>> Signed-off-by: xu xin >> >> The patch does not seem to be upstream / in mm-stable yet. >> >> Can you resend the original patch with these changes included and the >> reproducer referenced in the updated patch description? > > Sure, I thought the original patch was merged in linux-next. linux-next is just an integration tree. What you want to look out for is whether the patch ended up in mm-stable or mm-hotfixes-stable git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git As long as it's not in there (1) the commit id is not stable; and (2) we can still modify it. -- Cheers, David