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charset="utf-8" CMS-TYPE: 101P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20250306074101epcas1p4b24ac546f93df2c7fe3176607b20e47f References: <20250306074056.246582-1-s.suk@samsung.com> X-Stat-Signature: 8on7ka9ybqq9koknm67opkpex4d8kqgb X-Rspamd-Queue-Id: E67A1A0005 X-Rspamd-Server: rspam06 X-Rspam-User: X-HE-Tag: 1741313233-327149 X-HE-Meta: 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 szWYfV7w jg6J3Cl3E9LDybXKzW/dUMO2kbZ+Vp+abz32laOXA6oRXnPrr+biYmt9eo5RdAECwvF03e3UduT4/f9uyBT5rxYgwZnv6D7soQAAutJaMAoN8dLCCzIfHtWGyVgzgyLviB+T/MgeWt0N8wGNbMWIvsUNsa74mrb+rxDDS5VzAtVaPlShuO2hmrrFArYlEPIPcea+bt3rAB1sY9A7RNooYglkDGw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Fri, Mar 7, 2025 at 12:26=E2=80=AFAM=20Christoph=20Hellwig=20=0D=0A>=20wrote:=0D=0A>=20>=0D=0A>=20>=20On=20Thu,=20Mar=2006,= =202025=20at=2004:40:56PM=20+0900,=20Sooyong=20Suk=20wrote:=0D=0A>=20>=20>= =20There=20are=20GUP=20references=20to=20pages=20that=20are=20serving=20as= =20direct=20IO=0D=0A>=20buffers.=0D=0A>=20>=20>=20Those=20pages=20can=20be= =20allocated=20from=20CMA=20pageblocks=20despite=20they=20can=20be=0D=0A>= =20>=20>=20pinned=20until=20the=20DIO=20is=20completed.=0D=0A>=20>=0D=0A>= =20>=20direct=20I/O=20is=20eactly=20the=20case=20that=20is=20not=20FOLL_LON= GTERM=20and=20one=20of=20the=0D=0A>=20>=20reasons=20to=20even=20have=20the= =20flag.=20=20So=20big=20fat=20no=20to=20this.=0D=0A>=20>=0D=0A>=20=0D=0A= =0D=0AUnderstood.=0D=0A=0D=0A>=20Hello,=20thank=20you=20for=20your=20commen= t.=0D=0A>=20We,=20Sooyong=20and=20I,=20wanted=20to=20get=20some=20opinions= =20about=20this=20FOLL_LONGTERM=0D=0A>=20for=20direct=20I/O=20as=20CMA=20me= mory=20got=20pinned=20pages=20which=20had=20been=20pinned=20from=0D=0A>=20d= irect=20io.=0D=0A>=20=0D=0A>=20>=20You=20also=20completely=20failed=20to=20= address=20the=20relevant=20mailinglist=20and=0D=0A>=20>=20maintainers.=0D= =0A>=20=0D=0A>=20I=20added=20block=20maintainer=20Jens=20Axboe=20and=20the= =20block=20layer=20maillinst=20here,=0D=0A>=20and=20added=20Suren=20and=20S= andeep,=20too.=0D=0A=0D=0AThen,=20what=20do=20you=20think=20of=20using=20PF= _MEMALLOC_PIN=20for=20this=20context=20as=20below?=0D=0AThis=20will=20only= =20remove=20__GFP_MOVABLE=20from=20its=20allocation=20flag.=0D=0ASince=20__= bio_iov_iter_get_pages()=20indicates=20that=20it=20will=20pin=20user=20or= =20kernel=20pages,=0D=0Athere=20seems=20to=20be=20no=20reason=20not=20to=20= use=20this=20process=20flag.=0D=0A=0D=0Ablock/bio.c=20=7C=203=20+++=0D=0A= =201=20file=20changed,=203=20insertions(+)=0D=0A=0D=0Adiff=20--git=20a/bloc= k/bio.c=20b/block/bio.c=0D=0Aindex=2065c796ecb..671e28966=20100644=0D=0A---= =20a/block/bio.c=0D=0A+++=20b/block/bio.c=0D=0A=40=40=20-1248,6=20+1248,7= =20=40=40=20static=20int=20__bio_iov_iter_get_pages(struct=20bio=20*bio,=20= struct=20iov_iter=20*iter)=0D=0A=20=09unsigned=20len,=20i=20=3D=200;=0D=0A= =20=09size_t=20offset;=0D=0A=20=09int=20ret=20=3D=200;=0D=0A+=09unsigned=20= int=20flags;=0D=0A=20=0D=0A=20=09/*=0D=0A=20=09=20*=20Move=20page=20array= =20up=20in=20the=20allocated=20memory=20for=20the=20bio=20vecs=20as=20far= =20as=0D=0A=40=40=20-1267,9=20+1268,11=20=40=40=20static=20int=20__bio_iov_= iter_get_pages(struct=20bio=20*bio,=20struct=20iov_iter=20*iter)=0D=0A=20= =09=20*=20result=20to=20ensure=20the=20bio's=20total=20size=20is=20correct.= =20The=20remainder=20of=0D=0A=20=09=20*=20the=20iov=20data=20will=20be=20pi= cked=20up=20in=20the=20next=20bio=20iteration.=0D=0A=20=09=20*/=0D=0A+=09fl= ags=20=3D=20memalloc_pin_save();=0D=0A=20=09size=20=3D=20iov_iter_extract_p= ages(iter,=20&pages,=0D=0A=20=09=09=09=09=20=20=20=20=20=20UINT_MAX=20-=20b= io->bi_iter.bi_size,=0D=0A=20=09=09=09=09=20=20=20=20=20=20nr_pages,=20extr= action_flags,=20&offset);=0D=0A+=09memalloc_pin_restore(flags);=0D=0A=20=09= if=20(unlikely(size=20<=3D=200))=0D=0A=20=09=09return=20size=20?=20size=20:= =20-EFAULT;=0D=0A=0D=0A