From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-124.freemail.mail.aliyun.com (out30-124.freemail.mail.aliyun.com [115.124.30.124]) (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 A251E19AD5C for ; Tue, 30 Jun 2026 01:32:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782783142; cv=none; b=g7s647h19kJQE5wBZMvms8aWmSSMz7+9zHUicNokrVGoztTRwx000+dIH7V1jCD9TlRa8DNfow6fCRMuKW8epjFRTH4Qbk0/S+l4wqYva82rDUApgd14FuR44DfAULkGIQtzz4LA/e1DGqwR7Fxe47JLYz9zfnJrexXCHghGFMQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782783142; c=relaxed/simple; bh=XX8HraPOR4CEnEq6W+yv4xd7V4bHpCcvNV949Gvrs78=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=SDCtyYFIfdpti0lmsN8Uc3w5rwIczqfJRubmGokPFvxMwX/rLE7tXcEz/It//9bdi1K/pSlacCiC6XMqDE4BOfqauS6CiJEVQFH4a+pgkDvs5danQpWiQr69fqSbs6hgXAQkHTaxmvO9zuT/haoFBZMTpny/W5t1dHrUYTw5zeI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=TwYQJBuw; arc=none smtp.client-ip=115.124.30.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="TwYQJBuw" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1782783129; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=f/S/BIvky4ogkwc9B+8A9zZA9Y76XlrdAYcVHdo+9Qk=; b=TwYQJBuwUzT9yJmsvyUEXqK8En2t0HggSFDl4u0tKHtR4JkR/Dat5xHTTz4y/6VjYYyX0OZiWP/4LukEzl9nu99SUBm6P870z5Fu//qto1ECPQtZ9NOH6m8V46ki4be9AkWANSVLWf938GEbbd14/x40SJJ+3A37Mc+jVYeQUXM= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037033178;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0X5z0nPo_1782783127; Received: from 30.74.144.125(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0X5z0nPo_1782783127 cluster:ay36) by smtp.aliyun-inc.com; Tue, 30 Jun 2026 09:32:07 +0800 Message-ID: <4154c23d-faac-4d84-990e-a9a0aec5ed46@linux.alibaba.com> Date: Tue, 30 Jun 2026 09:32:07 +0800 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 1/4] mm/compaction: stop recording free page order in page->private To: Zi Yan , Andrew Morton , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Mike Rapoport Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260628-keep-subpage-private-zero-at-free-v1-0-f4ce3930d10f@nvidia.com> <20260628-keep-subpage-private-zero-at-free-v1-1-f4ce3930d10f@nvidia.com> From: Baolin Wang In-Reply-To: <20260628-keep-subpage-private-zero-at-free-v1-1-f4ce3930d10f@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/29/26 10:56 AM, Zi Yan wrote: > Commit 733aea0b3a7bb ("mm/compaction: add support for >0 order folio > memory compaction.") stores isolated free pages in an array indexed by free > page orders, it is no longer needed to store the order in each page's > ->private field. And there is no code using the stored order. Stop doing > that. > > It also prepares for an upcoming change that ensures subpage->private is I noticed that people tend to avoid using the term "subpage" now, though I understand what you mean by it here. :) [1] https://lore.kernel.org/all/20260623125723.2503832-1-dev.jain@arm.com/ > zero at page free time and the removal of set_page_private(0) from > prep_compound_tail(). In alloc_contig_frozen_range_noprof(), > isolate_freepages_range() is used to grab free pages from buddy allocator > and it leaves the aforementioned page->private set until > either split_free_frozen_pages() or prep_new_page() is called. That > triggers the upcoming subpage->private nonzero check along once > set_page_private(0) is removed from prep_compound_tail(), which is called > via prep_new_page(). > > Signed-off-by: Zi Yan > --- LGTM. Reviewed-by: Baolin Wang