From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.195 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793855656; b=TSWlyQANP8JWLoMcLTanpBjj9ffBNwvar3lZUArj0cRjv764fu5EnAcin5/ABSNVPg57 2rVA1pwZVwAtQEC/jnZ6/gf8KocbpEzNzGc14IPRxUVIP1l4FaoG28aBWlGWmyfNHXp9O YyJ9wd2wBnom5fDIK0KCGUh07i4ViZxEk65+lKxmm2xM9Nb9HRg/socBfF/6yxNyHddnW nuwBj44TD5pDkvnfHCH4Xewx9iYeeZqAV1aaJAyhVmNh5CJdSQN+K1ecfNfBUr1Ced8xR pIBf5cEfcTus+Y44OUmHGm8yUUqqYcUXQPtr+/RhRrdYZjRpIDXpamTdXdmJ1ic41BA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793855656; 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=XEqA3W+i3V3yHQk0EklCgzFHb8brEsF0K0ZpN1y8TEQ=; b=ojDoNKqwZUGWpx7M3J/uhuIV3drn9gQeXOwBHhRJ7A7byRfEuUCJ2fbEZxYJmmAGQlrV wtGIN6z9Wlt6qNh6eqb1XcasbKwA/nBx4MnaIf1UxVl2iEIKL5Oz8ovfPlVJEk8n/Lw0E I4CqgYBwNv1zOpE6fgHgn3AY9hNzBx0P+RofGf1BkoaAY0MvDS2QREJWk61jVSzvJ2Uqv tNKxf0YF5Ch6b6gQYPpVrjOTMNXm2vj2sCn0qxG/fdD3piwoKbbGaPUPxOTQTmAWSN4pu x+bAf6zhr1hj2cKGpy6n2TQrzkzNniLdG8enXyRrXA8rhv2lpQJpBzNEN03IcoL7j6Q== 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=KsgrMB7D; arc=none smtp.remote-ip=91.218.175.195 Received: from mta0.migadu.com (out-195.mta0.migadu.com [91.218.175.195]) (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 33F75606A326 for ; Thu, 5 Nov 2026 05:14:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 33F75606A326 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=KsgrMB7D X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=xnhL49rU8Si9Gh8RiV1Fb+XbOATfd6SeIOCBPYd10uQ=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793855651; v=1; x=1794460451; b=KsgrMB7D694W1cgfK/EHFM15yvG2BkZuFR+mdBgVSYckjw+DLCkwUBirfoAeHft8XIOcGH2G d3ci3wu5k/7KAiH/GtgmsUSAa1/Y78ZgoRSXyRS5PdkGfplIjDNWaLDsq1hYitBEVrqpLyg1OvE YAqzvdZsZhJmOFHobEYJnAp4= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id f77242cba51ecc71; Thu, 05 Nov 2026 05:14:10 +0000 X-Mizu-Trace-ID: f77242cba51ecc71 X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii X-Mailing-List: linux-kernel@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 v2 2/4] mm: gup: allow long-term pins of CMA-allocated HugeTLB folios From: Muchun Song In-Reply-To: <818fb0b4bbb234e4a2bd0552d61634f1a8431616.1793850539.git.zhengqi.arch@bytedance.com> Date: Thu, 5 Nov 2026 13:13:57 +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: <8F5F930D-A05E-4255-8E70-2567921A92A0@linux.dev> References: <818fb0b4bbb234e4a2bd0552d61634f1a8431616.1793850539.git.zhengqi.arch@bytedance.com> To: Qi Zheng X-Mailer: Apple Mail (2.3901.200.71.1.16) > On Nov 5, 2026, at 12:07, 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 > 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 But a nit bellow. > --- > 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 2d0b8a4c9974f..75dd40265d3f4 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -2975,35 +2975,8 @@ 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) > -{ > -#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 2b405cce2ca5c..e8503141bb275 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -2216,6 +2216,37 @@ 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); > + > + /* Explicit HugeTLB CMA allocations own their bitmap ranges. */ The description of "bitmap ranges" is weird, making me think what's the = meaning of bitmap. Please use more generic description here. > + 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