From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Kravetz Subject: Re: [PATCH 02/21] mm/hugetlb: correct max_huge_pages accounting on demote Date: Wed, 14 Sep 2022 11:43:05 -0700 Message-ID: References: <20220913195508.3511038-1-opendmb@gmail.com> <20220913195508.3511038-3-opendmb@gmail.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=corp-2022-7-12; bh=OyeFm6bnERPJ30RlB5vaLwq3t3uNQr23bGheHrRS04w=; b=x/YvSSLqAcDXsgVfzMMLsLujRRhvIJMimoi6iOhMnvenhnz6WE+0voHrpcrgmb1knu8Q lPpnVuLgN+ZXVQrLR6un2cb6wvSy7KLaLKagym7k+SR20teKvY2x8q/147qqL68CyP8w AjSwQcpVekxmqnMAhU6umy4AB7FK4QqaLPDF+oL12aiejj6N8Z3/bTJlJjhJbW06EAxa OZQx++5ulI0AJK/+zd36sLvCySAw9QcEo2PqLVWQ21l+CveAy10ygkxEAxYthB0bF1Ni hOK9O3x6EmI1dEUgOx4SpqJBMQT72TAeIfa4pEJ6QHzZdrcpyNZ8OXrQ7me3se/TdIat Og== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=OyeFm6bnERPJ30RlB5vaLwq3t3uNQr23bGheHrRS04w=; b=e64pzSSQ4WZ5jRbmqPgAHhJzgr3Omz68fgtBWaO0hbPlPASj8+xsVGBrrGHqZssr0aofGZwBK+FE3Xqn81yNb9E5/quUTFHar2u9w4dwODleKTd+zLdngAtmrcy8oVVfqEGiyCNmird3+eE24Sjio5AL4E/IWuHJfONzJjAHvUA= Content-Disposition: inline In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Florian Fainelli Cc: Doug Berger , Andrew Morton , Jonathan Corbet , Rob Herring , Krzysztof Kozlowski , Frank Rowand , Muchun Song , Mike Rapoport , Christoph Hellwig , Marek Szyprowski , Robin Murphy , Borislav Petkov , "Paul E. McKenney" , Neeraj Upadhyay , Randy Dunlap , Damien Le Moal , David Hildenbrand , Zi Yan , Oscar Salvador , Hari Bathini On 09/14/22 10:26, Florian Fainelli wrote: > On 9/14/22 10:23, Mike Kravetz wrote: > > On 09/13/22 12:54, Doug Berger wrote: > > > When demoting a hugepage to a smaller order, the number of pages > > > added to the target hstate will be the size of the large page > > > divided by the size of the smaller page. > > > > > > Fixes: 8531fc6f52f5 ("hugetlb: add hugetlb demote page support") > > > Signed-off-by: Doug Berger > > > --- > > > mm/hugetlb.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > > index e070b8593b37..79949893ac12 100644 > > > --- a/mm/hugetlb.c > > > +++ b/mm/hugetlb.c > > > @@ -3472,7 +3472,8 @@ static int demote_free_huge_page(struct hstate *h, struct page *page) > > > * based on pool changes for the demoted page. > > > */ > > > h->max_huge_pages--; > > > - target_hstate->max_huge_pages += pages_per_huge_page(h); > > > + target_hstate->max_huge_pages += pages_per_huge_page(h) / > > > + pages_per_huge_page(target_hstate); > > > return rc; > > > } > > > > This has already been fixed here, > > > > https://lore.kernel.org/linux-mm/20220823030209.57434-2-linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org/ > > > > Could we slap the Fixes tag when this Miaohe's patch series gets accepted > since the offending commit is in v5.16 and beyond. Thanks! We could. However, this fix/change does not really have any impact on the way code functions (unless I am mistaken). See my analysis at, https://lore.kernel.org/linux-mm/YvwfvxXewnZpHQcz@monkey/ -- Mike Kravetz