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Content-Language: en-US To: Sebastian Andrzej Siewior , linux-mm@kvack.org Cc: Michal Hocko , Thomas Gleixner References: From: Vlastimil Babka In-Reply-To: Content-Type: text/plain; charset=UTF-8 X-Stat-Signature: c8qdc3th9f5xuagq3ntgg859i4dfffpe Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=OguJkPpi; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=DCJXYK4R; spf=pass (imf08.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.28 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 22F6F16001E X-HE-Tag: 1648030177-193458 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 3/22/22 18:39, Sebastian Andrzej Siewior wrote: > Run into > | =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D > | WARNING: possible circular locking dependency detected > | 5.17.0-next-20220322 #19 Not tainted > | ------------------------------------------------------ > | kswapd1/513 is trying to acquire lock: > | ffff888555b7e628 (&xfs_dir_ilock_class){++++}-{3:3}, at: xfs_icwalk_a= g+0x36c/0x810 > |=20 > | but task is already holding lock: > | ffffffff82a2fb20 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x600/0x= 740 > |=20 > | which lock already depends on the new lock. > |=20 > |=20 > | the existing dependency chain (in reverse order) is: > |=20 > | -> #1 (fs_reclaim){+.+.}-{0:0}: > | fs_reclaim_acquire+0xaa/0xe0 > | __kmalloc_node+0x65/0x3e0 > | xfs_attr_copy_value+0x70/0xa0 > =E2=80=A6 >=20 > and I think this is similar to commit > 704687deaae76 ("mm: make slab and vmalloc allocators __GFP_NOLOCKDEP= aware") >=20 > and maybe something like this: >=20 > diff --git a/mm/slab.h b/mm/slab.h > --- a/mm/slab.h > +++ b/mm/slab.h > @@ -717,7 +717,7 @@ static inline struct kmem_cache *slab_pre_alloc_hoo= k(struct kmem_cache *s, > struct obj_cgroup **objcgp, > size_t size, gfp_t flags) > { > - flags &=3D gfp_allowed_mask; > + flags &=3D gfp_allowed_mask | __GFP_NOLOCKDEP; Hmm but gfp_allowed_mask already should contain __GFP_NOLOCKDEP after kernel_init_freeable() is reached. I doubt we can reach fs or reclaim code before that? > =20 > might_alloc(flags); > =20 > ? >=20 > Sebastian