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 970383A35DF for ; Thu, 22 Jan 2026 10:23:22 +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=1769077402; cv=none; b=ne0xLA1i0thWwmXEVSzMGX9JM+uukckScd4QjNv3RRG7Vc/JhqDGyGJ0dRgEA5+PXUpM8cV8ogZpM255LaxV8kKYs7sjKisauHnlHy6l0eANCUwukNQDsBUZIgs1LHvDr8exf822aepw5mI8JfXi2YRmPACckBTi8bLqlXbTyFw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769077402; c=relaxed/simple; bh=0te499sdFFCQEZXIav3Juo25FvmqHOPhfdLK4InvpvY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=og2V5gF1VSLPuDgYknzPYRXub8olAPIjHNoaXCjbb8tnTW89mq9wWQFkBEmH8VZu7sYhSt9n+IAV7ncKVEgEm58MaKmkbVRw3Yz5Y3M/hSgDUA7IZkdcx7ClhZimOleYxccz+5h3AJ+rfQG0DRZKDQHcAQ4EgKA+RZZo6wWSOzg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=f9A2yDif; 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="f9A2yDif" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3463AC116C6; Thu, 22 Jan 2026 10:23:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769077402; bh=0te499sdFFCQEZXIav3Juo25FvmqHOPhfdLK4InvpvY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=f9A2yDifc9zaJDGikz+SPpBGjANGZ4ZtYGk9NJnIjH1Xhs6PV/U1QQxa4KvrGTQQn okMz3uRIwBrZRTJoWDuhfOScqMTBWMVB0i6QB/mCDQDzT8QwInJ+E5+y/uWJspAjdm OYMX6nw1k3adDJWMx9VzX2VUN7uEnv4gTTDkvpLHmEHhQyKUfD1znHPns4zX95E/wv 8ppBdCUsPUUkBoTR+Fj3t54GAIUrJuGBXEdkuk03fB44t/BUNWZOpDSC6GRFuVxH4o OOpWTLsceSevIae0ARyA9C3rEPmchP8AGB7yd3WVbRp7hJAizg7HNWjNfKcaUnp69B QnMgNHfAtmNLw== From: Pratyush Yadav To: ranxiaokai627@163.com Cc: akpm@linux-foundation.org, graf@amazon.com, kent.overstreet@linux.dev, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, pasha.tatashin@soleen.com, pratyush@kernel.org, ran.xiaokai@zte.com.cn, rppt@kernel.org, surenb@google.com Subject: Re: [PATCH v3] kho: init alloc tags when restoring pages from reserved memory In-Reply-To: <20260122042506.175897-1-ranxiaokai627@163.com> (ranxiaokai's message of "Thu, 22 Jan 2026 04:25:06 +0000") References: <20260121120804.d1334ea0cc66b4a6de691cbf@linux-foundation.org> <20260122042506.175897-1-ranxiaokai627@163.com> Date: Thu, 22 Jan 2026 10:23:18 +0000 Message-ID: <2vxzqzriaquh.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Hi Ran, On Thu, Jan 22 2026, ranxiaokai627@163.com wrote: >>> From: Ran Xiaokai >>> >>> Memblock pages (including reserved memory) should have their allocation >>> tags initialized to CODETAG_EMPTY via clear_page_tag_ref() before being >>> released to the page allocator. When kho restores pages through >>> kho_restore_page(), missing this call causes mismatched >>> allocation/deallocation tracking and below warning message: >>> >>> alloc_tag was not set >>> WARNING: include/linux/alloc_tag.h:164 at ___free_pages+0xb8/0x260, CPU#1: swapper/0/1 >>> RIP: 0010:___free_pages+0xb8/0x260 >>> kho_restore_vmalloc+0x187/0x2e0 >>> kho_test_init+0x3c4/0xa30 >>> do_one_initcall+0x62/0x2b0 >>> kernel_init_freeable+0x25b/0x480 >>> kernel_init+0x1a/0x1c0 >>> ret_from_fork+0x2d1/0x360 >>> >>> Add missing clear_page_tag_ref() annotation in kho_restore_page() to >>> fix this. >>> >>> Signed-off-by: Ran Xiaokai >>> --- >>> It is based on linux-next 20260120. I dont konw whether this base is ok ? >> >>It's awkward. >> >>Your v2 patch was based on Linus mainline. This is appropriate, as the >>patch should be sent to Linus soon and it has cc:stable, so -stable >>maintainers will try to backport it into earlier kernels. >> >>However your v3 patch is dependent upon other material ("kho: simplify >>page initialization in kho_restore_page()") which is scheduled for >>6.20(?)-rc1. > > I think i misunderstood Pratyush's last reply: > "I suggested a re-roll of this patch based on top of my cleanup patches > [1], since I think with those the end result is a bit nicer." I was giving context to Andrew about the whole thing. I thought it was a good idea when I suggested it to you, but at the time I didn't think that this will go in the hotfixes branch. If it goes in hotfixes, it doesn't make sense to base it on a series for the next kernel. Sorry for the confusion. > >>For a prompt, backportable merge it's best to base the fix on latest >>Linus mainline, please. >> >>You didn't actually describe why v3 is different from v2. If the >>v2->v3 changes are just nice-to-have then let's redo those and base >>them on linux-next in the usual fashion. > >>Unless I'm missing something, your well-reviewed, decently-tested v2 >>patch remains suitable for upstreaming during 6.18-rcX > > v2 version just fixed the folio case(compound page), but didn't fix the > contiguous order 0 pages case. So i think it is better to send a v3 version > base on lastest Linus tree and drop the v2 version. Yep, that would be the idea. Resend the changes fixing both compound and non-compound cases on top of Linus' tree and ignore my "simplify page initialization" series. And then I can later resend my series on top of your patch. -- Regards, Pratyush Yadav