From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4D1F5C55162 for ; Sun, 2 Aug 2026 12:16:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2EC006B007B; Sun, 2 Aug 2026 08:16:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 29D2C6B0088; Sun, 2 Aug 2026 08:16:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1B4276B008A; Sun, 2 Aug 2026 08:16:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id E51A56B007B for ; Sun, 2 Aug 2026 08:16:24 -0400 (EDT) Received: from smtpin24.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 3D8018048B for ; Sun, 2 Aug 2026 12:16:24 +0000 (UTC) X-FDA: 85056227088.24.48C0247 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) by imf13.hostedemail.com (Postfix) with ESMTP id 5BA0320004 for ; Sun, 2 Aug 2026 12:16:22 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=m9RfD4K1; spf=pass (imf13.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.180 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1785672982; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=j3oeIu1NO1s3LH22n1O12mVtuttJMeqOoFdM19I5ia0=; b=m1dVIDFiqqnGW8Su0VNEWsNiqyq91mDTbBjtEJrvoGKGJEw6lrT2/lzl2JUobCQRhwkukI 7JtzYDhpVJKwvnueHkT6PghjkKJFmxELmIxbOD1DlAVDWd1T/Z9cE2g46mFxHwtoWJ07TK SFn8vUDNAB/9JQIN0utaJllwruw+vrc= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1785672982; b=8S7uz0FTa15MSW3PPY1kQK/Q4TyoB+xrW+ya587xwGi4YoWlwaKHAbaybbo0KejXFj1StU s8HVnlUNJHx8mJYHFWZLB6Lr0LZsu9IqxjuDbEE4RPDdd8AlpoE8PM2kALVm0pavO0dWfR mWwchAx2pNio68jJexNYn1U5i1K7Eqk= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=m9RfD4K1; spf=pass (imf13.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.180 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1785672980; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=j3oeIu1NO1s3LH22n1O12mVtuttJMeqOoFdM19I5ia0=; b=m9RfD4K1o5ZHsE+3Sj33aVH5mGou/ZnrDu+jrIoNw6LfiuPjpRUWrO9vlbO8q6fHgSadH8 xPt4D7A0BcDKrfEKpmPi0RVOMcS5nkw9ihECZXvoRJW2Vk4Fg4Z2WuWUuenlXQkLacStHQ wTOwDN+GA7Y7+unHikiw7354IdBKdjM= From: Usama Arif To: Zi Yan Cc: Usama Arif , David Hildenbrand , "Matthew Wilcox (Oracle)" , Andrew Morton , Muchun Song , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Gregory Price , Ying Huang , Alistair Popple , Johannes Weiner , Qi Zheng , Shakeel Butt , Kairui Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador Subject: Re: [PATCH RFC 05/14] mm/hugetlb: use direct assignment instead of folio_change_private() Date: Sun, 2 Aug 2026 05:16:12 -0700 Message-ID: <20260802121613.1590412-1-usama.arif@linux.dev> In-Reply-To: <20260731-remove-pg_private-v1-5-142c97ba3562@nvidia.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: 5BA0320004 X-Stat-Signature: wrmxrzayeim7r9g6m8qgqwugeoixycxw X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1785672982-952505 X-HE-Meta: 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 NDAQFGZF ecXTAmM0HUVGmUNRB9p5kwDTLye9lHCBNh5u9MBSg7ov6RKJ34Vus2mRZ9DGM3kmexLmkhY06VHjhMp3c3fmZ23iU0+rrn98BuAAoe6cRNnHPauYBR51Y0/kcEhVHNnfZmCCm6vtOUclGr8DsLchzLXKm5HbDTdFr+PW5Yg1vSKBaZMmSHLkWVuSjKDhi3mtGJ5psSQHcu1x3Db//UVUooEaWV86wvi6zmc9PO+t79jp0RaPw8dXgmjNXUMt22slScEczUxRcAF3tWowossolRMRuN0tlyYKc8VxG388szmZkrNdzIliRROHakC+aw5tux4gaW4AzAMALePdUsJ3x6pHX1iqgUtPi5UdoEvTogreJb88FOadzBqJo8XJNlMjyUAirMVRocxpFI9F4UKr/5uRcRKloApmOzOFN Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, 31 Jul 2026 22:13:28 -0400 Zi Yan wrote: > folio_change_private() should be used along with folio_attach_private() and > folio_detach_private(), where adding and remove ->private content requires > folio refcount change. add_hugetlb_folio() simply sets folio->private to > NULL without refcount manipulation. Change it to direct assignment to avoid > semantic confusion. > > It prepares for a future commit that remove PG_private. > > No funtional change intended. > > Assisted-by: Claude:claude-opus-4-8 > Assisted-by: Codex:gpt-5 > Signed-off-by: Zi Yan > To: Muchun Song > To: Oscar Salvador > To: Andrew Morton > Cc: David Hildenbrand > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > mm/hugetlb.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index a77c3c1cb8943..0abaeb47890cb 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1433,10 +1433,10 @@ void add_hugetlb_folio(struct hstate *h, struct folio *folio, > } > > __folio_set_hugetlb(folio); > - folio_change_private(folio, NULL); > + folio->private = NULL; > /* > - * We have to set hugetlb_vmemmap_optimized again as above > - * folio_change_private(folio, NULL) cleared it. > + * We have to set hugetlb_vmemmap_optimized again as hugetlb page flags > + * are all cleared above. > */ The return value of folio_change_private() is never checked so LGTM. In the comment, saying "above" is not very clear. How about something like: /* * The hugetlb flags live in folio->private, so the assignment * above cleared them all; restore hugetlb_vmemmap_optimized. */ With the comment clearer, feel free to add Acked-by: Usama Arif > folio_set_hugetlb_vmemmap_optimized(folio); > > > -- > 2.53.0 > >