From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E95B53C8737; Mon, 22 Jun 2026 15:47:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782143225; cv=none; b=EWFNrRX8sMbWlKEhdhtluVgTIaRL9fFXYM8xS6QJgn+8GbLpCWU5N8JmZVvWqQfsyBoYqgDNV0obpbvRHh9EI+kRW0mwSGUGDr1JvJe7ykb260MnxE35pDHsu73Hds9eA34YG4iz6Cm2B4+2RBNRWFO8gxruxLvkgbqnw+BGhps= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782143225; c=relaxed/simple; bh=0+de0zXtiLclgZC23qL7jAbhKZXMpbjdSbp2UUjLG6U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pxn1wtbhtY9+zpDfyif5Zwh5ZsSRvAgZaeGSJRydW9TYY7s740Oi1v33WDbubNzTqdldcvfouCJOOwS+9xx/1KYwx4aB1eXRsApflux+H0zkUYo63ke6IJNC1UJGpyTu2WzgBiRIaIg32YCo8o63P8a3kgII+DkdyyTDzPRV13M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UOaTZUid; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UOaTZUid" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B3AD1F000E9; Mon, 22 Jun 2026 15:47:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782143224; bh=yoWdqaO8IqnJhMic0naLfg9Wn06LbUJ/uEvj5S1j1zc=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=UOaTZUidvSSHad4akjDsUxFvvXJTkNlMnJWzr8mhmjDu93CmYPG5szEye5UWCoKVH q+jWJ25h/c0Yru7Lhi/OPOhsPzzZiuCjHuEqMo6nbU24ij++eyg0Vw7berLgMAmGf6 Ut0HYWoZZP3ajm1TCRkqYZLyO82bv9hto2Kv4XmcD0v9d95bZU6B041fbJfjymxTZz 0fM3PYOMj1VGqJB38MFDWxGEnO3f1MKYZxYapUlyLmT/Thq3G5DP4SOyBZu3fA4nQR 9wicAQNAX2kOTKgZQXJSclNUajrYc9X3HzJ6E0EhjfQkvUdDFMDa5ZffvDz4BxVX1d 21RNcqU9SIgmA== Message-ID: Date: Mon, 22 Jun 2026 17:47:00 +0200 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 hotfix] mm/compaction: handle free_pages_prepare() properly in compaction_free() Content-Language: en-US To: Zi Yan , Andrew Morton , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Baolin Wang Cc: Jiaqi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260622-handle_free_pages_prepare_in_compaction_free-v1-1-fcf3b14abcf7@nvidia.com> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/22/26 17:30, Zi Yan wrote: > free_pages_prepare() can fail but compaction_free() does not handle the > failure case. Failed pages should not be added back to cc->freepages for > future use, since they can be either PageHWPoison or free_page_is_bad() > and might cause data corruption. > > Fixes: 733aea0b3a7bb ("mm/compaction: add support for >0 order folio memory compaction.") > Signed-off-by: Zi Yan > Cc: stable@vger.kernel.org Reviewed-by: Vlastimil Babka (SUSE) > --- > free_pages_prepare() can fail if a page is PageHWPoison or > free_page_is_bad(). compaction_free() needs to handle these cases to > prevent failed pages being reused in cc->freepages. > --- > mm/compaction.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index b776f35ad0200..f08765ade014c 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -1875,15 +1875,14 @@ static void compaction_free(struct folio *dst, unsigned long data) > int order = folio_order(dst); > struct page *page = &dst->page; > > - if (folio_put_testzero(dst)) { > - free_pages_prepare(page, order); > + if (folio_put_testzero(dst) && free_pages_prepare(page, order)) { > list_add(&dst->lru, &cc->freepages[order]); > cc->nr_freepages += 1 << order; > } > cc->nr_migratepages += 1 << order; > /* > - * someone else has referenced the page, we cannot take it back to our > - * free list. > + * someone else has referenced the page or free_pages_prepare() fails, > + * we cannot take it back to our free list. > */ > } > > > --- > base-commit: 13a1e1a618858407fa12c391f664ea750651f6b2 > change-id: 20260621-handle_free_pages_prepare_in_compaction_free-7cca3ff08367 > > Best regards,