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a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776904424; bh=YFcpm1Q2IEqSIizxpG40qUfklzA44nCTjWRmWInHJ50=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=EoLLOiFASH/63sE64eVfVLIOEbfRV96kbmC4VrUvH4yMEVwrEiw8yUQIKLqOLgAaN Nu24G1HjVtlW+Cg/8hC6iR8C9K/nJnI4Ryajt7KHdG+FS3DUcsp9LloBqXPub6SfB9 3kFFEvWSepb2VAMhcBYIhvCMC8K9j8suP/O+K8PeYNoG94fJUn1Ep0OtuHX3Rx+Ewz Q7KQ6m8nTdqHe/82OlojK/owwTEdUan56EGhFZIieFqfosN9Ah/J9m3kN91ZVJiJxz N48yREmPDAsOrE2ifOrW9dFWQWdwuLoxmAUZGkkvS1t5J8A1zQmvJ3yB3p16PqZ/5B /pi2xHiYpzWqw== Received: by mail-yx1-f45.google.com with SMTP id 956f58d0204a3-6501d242e3fso5903556d50.0 for ; Wed, 22 Apr 2026 17:33:44 -0700 (PDT) X-Gm-Message-State: AOJu0YxASYWwhDUNK9xzTW+rMRuM+jvjShhMS2MEm0Yp7gLVl0tF+osm R86lny0y4p/bnkL2f1eLgxB6F/tbrGQfGXd2MPKHJnWBDDYVlTa4LM1FL1WLqGcjev8KFFtL00/ cHm65wvEWClQQCn92pRf6fKBcD7qzq68qVqv05TPZ2A== X-Received: by 2002:a05:690e:408a:b0:654:2882:42ae with SMTP id 956f58d0204a3-654288245cbmr14523945d50.25.1776904423511; Wed, 22 Apr 2026 17:33:43 -0700 (PDT) MIME-Version: 1.0 References: <20260417033951.1111038-1-baoquan.he@linux.dev> <20260417033951.1111038-3-baoquan.he@linux.dev> In-Reply-To: From: Chris Li Date: Wed, 22 Apr 2026 17:33:32 -0700 X-Gmail-Original-Message-ID: X-Gm-Features: AQROBzCXNkRuswSYg5pgaKJzL8SCIfc5cKXNShZru9-WLK9_BID2HRgzyPIHEpw Message-ID: Subject: Re: [PATCH v4 2/3] mm/swap: use swap_ops to register swap device's methods To: Baoquan He Cc: linux-mm@kvack.org, akpm@linux-foundation.org, usama.arif@linux.dev, baohua@kernel.org, kasong@tencent.com, nphamcs@gmail.com, shikemeng@huaweicloud.com, youngjun.park@lge.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 677641C0012 X-Rspamd-Server: rspam12 X-Stat-Signature: e5bp3ca37gehp4amag5i6zjee38ma5b5 X-Rspam-User: X-HE-Tag: 1776904425-28454 X-HE-Meta: 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 5qDG5c58 fY8oMgm+x2c5+r8zGHk771o9edFh6fS06gJESNJSq/7m1RsTs44Jk+NpCMaN+jQY9fgqUcPkQ67t7ofMllyJBZ5w/DZtbmF4XzlrOhg1VSkHYCrm2F/YBdiguEp4q1TjHOx76NxDlcm3xlfCTQiMJfDMLV9rtnzQqXsDV2zSoW9xpa0l4a0wBpZ9FarXLfOkNWDbGpW6IdgAeqoHfDDNwOSIUpqxI1li6h0+/YM0og1ohM7HhI+9c9mm8mzt6OWFA1GSReCMl0ytSPWrKqllf52sFkZTCheExHwkoydAbQTC+SbEA6P85E8n2x8kOvOmgiO1oNMSkHYzmjWI= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Apr 21, 2026 at 6:48=E2=80=AFPM Baoquan He w= rote: > > On 04/17/26 at 07:30pm, Chris Li wrote: > > On Thu, Apr 16, 2026 at 8:40=E2=80=AFPM Baoquan He wrote: > ...snip... > > > +int init_swap_ops(struct swap_info_struct *sis) > > > +{ > > > + /* > > > + * ->flags can be updated non-atomically, but that will > > > + * never affect SWP_FS_OPS, so the data_race is safe. > > > + */ > > > + if (data_race(sis->flags & SWP_FS_OPS)) > > > + sis->ops =3D &bdev_fs_swap_ops; > > > + /* > > > + * ->flags can be updated non-atomically, but that will > > > + * never affect SWP_SYNCHRONOUS_IO, so the data_race is safe. > > > + */ > > > + else if (data_race(sis->flags & SWP_SYNCHRONOUS_IO)) > > > + sis->ops =3D &bdev_sync_swap_ops; > > > + else > > > + sis->ops =3D &bdev_async_swap_ops; > > > + > > > + if (!sis->ops || !sis->ops->read_folio || !sis->ops->write_fo= lio) > > > + return -1; > > Nitpick: > > > > For int type error return, you should use -EINVAL or some thing with > > error code. If you don't care about error code, change the return type > > to bool instead. > > Thanks for careful reviewing, returning -EINVAL looks better, I will > change like that and repost. You don't have to repost it as a new series. You can post one small incremental update for the -EINVAL change and ask Andrew to fold it in. Hi Andrew, I think this swap ops series can be merge to mm-unstable with the review. Keep in mind that Baoquan might have a very minor follow up patch relate to -EINAL error code. Chris