From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.233 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794382996; b=aALR++MvXOCUZl4mw7dV8caZHcz6M52bKN8hoPX4hMv1ThsNRoWcuZFi41rf4egU/KRW NmBfE7P8cz/OLWYcBaO8aqtSqC7823AwVn7SEW7D+gTSthHG0+9hble0Vl0/iwVjdzTXs sZzC5JE74Id+Sk4nrRrNNHsHzVWLfd/Xnpt3/hqYrVxkxLn4DyLFq0ERuSw/1fw3ie8dH uoNSveHrA69DEYWBTi+kvAW9hiVKIMARa2t8AZs8U1gZJaMUsb4fNR69HZYvk4pVMIMg2 EkuYBpkwmfYnoTk6dz6VVR8gtJ8ktahJo/jg2+hewYuO+YuwKovNHXV/KG/UUZQxORQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794382996; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Mime-Version:Subject:From: In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References: To:X-Mailer; bh=EfxdzkdgDHIptdiFFicHU4j+CsK16rJHdQjUlG9Ac2o=; b=hAThczqMtw5WX6/iqH0eFKDCOz0eKpe9R1LEjP4VXoWS+l57ckS5+jHALeELiKpXQnaB y/ASQDDqZUbSk35kNIIKnfB/dWHYgS2MTiCQ8YVeCgnPZIQLx72kFL2efplerCA/ukZSh o763TmLV4AZZi2F6V+86bhHarUojkiBDhfLqio4FROOJixkoNVvpfGMUImkOV9MBcSpur o/fU4ml4BN7EPhMxpVrzVNx4VUviNA/5Gfd0lQt5r79kkXWRFKZ7+JEawJjJQ/q0w04ie cn/T/nTkv8/+LNvqUcrlQ0e7GOGbkRG6Oh3rU3CHZKyA6BiCWch5QhU2ex6AkNhanUg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Kcr8dbbk; arc=none smtp.remote-ip=91.218.175.233 Received: from mta0.migadu.com (out-233.mta0.migadu.com [91.218.175.233]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ACB8C606A31C for ; Wed, 11 Nov 2026 07:43:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org ACB8C606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Kcr8dbbk X-Envelope-To: stable@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=2ou7idqYN0vwf8nRLylpa5vOfvnrhR/VXDNnnd6BgTQ=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794382992; v=1; x=1794987792; b=Kcr8dbbk8h+TSq+Yyw2YDIeSvwq6yLwpn8tc9FoowpR6nJsm66vFNZV0q63S6RgLxmroBChc WecxsGdtXIm0yDJpOcwWcwvoeDE1fmBqgl2/rqwDO3dDRbmCq7NHYAHz0g9Pc24beyB4ykRUhPD IYs1LeyW5IqEBhh54uHO5AjM= X-Envelope-To: stable@vger.kernel.org Received: by mta11.migadu.com with ESMTPS id 12f4ebcce8353a82; Wed, 11 Nov 2026 07:43:12 +0000 X-Mizu-Trace-ID: 12f4ebcce8353a82 X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.200.71.1.16\)) Subject: Re: [PATCH v4 2/3] mm: gup: allow long-term pins of CMA-allocated HugeTLB folios From: Muchun Song In-Reply-To: <503c9f6d869e3206c6fd591de962c3d619b73825.1794379433.git.zhengqi.arch@bytedance.com> Date: Wed, 11 Nov 2026 15:42:56 +0800 Cc: osalvador@suse.de, David Hildenbrand , akpm@linux-foundation.org, azpijr@gmail.com, Lance Yang , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Qi Zheng , stable@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <80FED512-77D2-4D49-BAE5-745CE1F711CA@linux.dev> References: <503c9f6d869e3206c6fd591de962c3d619b73825.1794379433.git.zhengqi.arch@bytedance.com> To: Qi Zheng X-Mailer: Apple Mail (2.3901.200.71.1.16) > On Nov 11, 2026, at 14:46, Qi Zheng wrote: >=20 > From: Qi Zheng >=20 > Long-term pinning treats explicitly CMA-allocated HugeTLB folios as > unpinnable, causing unnecessary migration or pinning failures. >=20 > These folios already own their CMA bitmap ranges, and memory blocks Commit message needs updating to bitmap as well. > overlapping CMA areas cannot be offlined. Allow HugeTLB folios with > HPG_cma to be pinned directly, including in ZONE_MOVABLE. >=20 > Fixes: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic = hugepages using cma") > Cc: stable@vger.kernel.org > Suggested-by: Muchun Song > Signed-off-by: Qi Zheng > Acked-by: Muchun Song > Reviewed-by: Oscar Salvador > Reviewed-by: Jose A. Perez de Azpillaga > --- > include/linux/mm.h | 29 +---------------------------- > mm/gup.c | 31 +++++++++++++++++++++++++++++++ > 2 files changed, 32 insertions(+), 28 deletions(-) >=20 > diff --git a/include/linux/mm.h b/include/linux/mm.h > index b0da9be413098..47d1d96bfc7fd 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -2954,35 +2954,8 @@ static inline bool is_zero_folio(const struct = folio *folio) > return is_zero_page(&folio->page); > } >=20 > -/* MIGRATE_CMA and ZONE_MOVABLE do not allow pin folios */ > #ifdef CONFIG_MIGRATION > -static inline bool folio_is_longterm_pinnable(struct folio *folio) I think David prefer to move this function first, then fix it in a = separate patch, right? Thanks, Muchun > -{ > -#ifdef CONFIG_CMA > - int mt =3D folio_migratetype(folio); > - > - if (mt =3D=3D MIGRATE_CMA || mt =3D=3D MIGRATE_ISOLATE) > - return false; > -#endif > - /* The zero page can be "pinned" but gets special handling. */ > - if (is_zero_folio(folio)) > - return true; > - > - /* Coherent device memory must always allow eviction. */ > - if (folio_is_device_coherent(folio)) > - return false; > - > - /* > - * Filesystems can only tolerate transient delays to truncate = and > - * hole-punch operations > - */ > - if (folio_is_fsdax(folio)) > - return false; > - > - /* Otherwise, non-movable zone folios can be pinned. */ > - return !folio_is_zone_movable(folio); > - > -} > +bool folio_is_longterm_pinnable(struct folio *folio); > #else > static inline bool folio_is_longterm_pinnable(struct folio *folio) > { > diff --git a/mm/gup.c b/mm/gup.c > index ebbfee09b7278..fdafc5a1b78ed 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -2219,6 +2219,37 @@ struct page *get_dump_page(unsigned long addr, = int *locked) >=20 > #ifdef CONFIG_MIGRATION >=20 > +bool folio_is_longterm_pinnable(struct folio *folio) > +{ > +#ifdef CONFIG_CMA > + int mt =3D folio_migratetype(folio); > + > + /* These HugeTLB folios own the CMA memory, so they can be = long-term pinned. */ > + if (folio_test_hugetlb(folio) && folio_test_hugetlb_cma(folio)) > + return true; > + > + if (mt =3D=3D MIGRATE_CMA || mt =3D=3D MIGRATE_ISOLATE) > + return false; > +#endif > + /* The zero page can be "pinned" but gets special handling. */ > + if (is_zero_folio(folio)) > + return true; > + > + /* Coherent device memory must always allow eviction. */ > + if (folio_is_device_coherent(folio)) > + return false; > + > + /* > + * Filesystems can only tolerate transient delays to truncate = and > + * hole-punch operations > + */ > + if (folio_is_fsdax(folio)) > + return false; > + > + /* Otherwise, non-movable zone folios can be pinned. */ > + return !folio_is_zone_movable(folio); > +} > + > /* > * An array of either pages or folios ("pofs"). Although it may seem = tempting to > * avoid this complication, by simply interpreting a list of folios as = a list of > --=20 > 2.54.0 >=20