From nobody Tue Feb 10 05:09:46 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9C58EB64D8 for ; Thu, 22 Jun 2023 08:58:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231736AbjFVI64 (ORCPT ); Thu, 22 Jun 2023 04:58:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231624AbjFVI6D (ORCPT ); Thu, 22 Jun 2023 04:58:03 -0400 Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F3F72703 for ; Thu, 22 Jun 2023 01:55:32 -0700 (PDT) Received: by mail-pg1-x52d.google.com with SMTP id 41be03b00d2f7-51f64817809so680028a12.1 for ; Thu, 22 Jun 2023 01:55:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1687424131; x=1690016131; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Rw+THIB7nYtdEoKFrcRpf+DtRSemfk8nQmXyWQCWLOU=; b=DMwdTIl9g+okPZHJv8qTrb+gYAPEj9v1sxcSDlzK5ch7N+TuIC/BcFHKohEZo55ND8 XU29tOhBmT8qLwPtzV/wEHQ6iOqaUqSy8YTL9GNxgMKyLojaih+JCKFRV8sA50VDaMhL 4ENhUxcmuP8buO31FrzpXihlkiHbj7xjQ5jQCZ/XAAfjoNJ005ZfE8KQlMXJnunKzCcO Fe2zvwkJ/uki5/MCqM+WcH9ckA1bFEYVaXIUmwP+4s7h2vpQxpmZaq/OfODYIqbWYJLH gNO1EGlemqhIu8SDpgbpJo6kXONx1A4ErgZXcMZMC3KoLi5/PQ7Kas2P+1tIIIXAXu47 3GiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687424131; x=1690016131; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Rw+THIB7nYtdEoKFrcRpf+DtRSemfk8nQmXyWQCWLOU=; b=YA2BnfNU/C9peZOiTAjiP3GHZL1Pr7ShIJk/ujNwxkOJ3xfZcWaDLSIZuBqms5nzD/ QM9L8tKOh5C6qmZxutaXYqE4y/LnBp1HClSts+vTC7L+OgKX7j/dZ6l+VZ50SGpNmQ57 Maa3xhLXPjOuKcujD9vrlHgvOC/yDKOI6ewkdEby8CLUYF2yxzZ5uDH5PEp4B1sPfgTc 3iCPGPUT1ZEsjIARq6sqddL09r7p6d3/NwpDR3g2obET0eNGVTERpslfr8hLlfMoooJ4 onF2P00S7rlva95XVj7QJYi5k+D8Hcot+9PB8L+fKG6KwT48JfQWpCvr1HI/LFefZJF8 Yf4Q== X-Gm-Message-State: AC+VfDx6D221ccqtmQPpFpWZWKI24ndqKXHKJMuEIvLgFYMcatqR7WEB wEe0pUTmiDBMQxn+9mGCriHTCg== X-Google-Smtp-Source: ACHHUZ74w6zUyxxONmkdhWFpbjqcQv1Ri8s1BW02LunWtr1K9sXtmODVbQHvvX6jLBNiniDuaX5mmA== X-Received: by 2002:a17:902:d489:b0:1b4:ddef:841e with SMTP id c9-20020a170902d48900b001b4ddef841emr21417877plg.4.1687424131373; Thu, 22 Jun 2023 01:55:31 -0700 (PDT) Received: from C02DW0BEMD6R.bytedance.net ([139.177.225.254]) by smtp.gmail.com with ESMTPSA id h2-20020a170902f7c200b001b549fce345sm4806971plw.230.2023.06.22.01.55.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Jun 2023 01:55:31 -0700 (PDT) From: Qi Zheng To: akpm@linux-foundation.org, david@fromorbit.com, tkhai@ya.ru, vbabka@suse.cz, roman.gushchin@linux.dev, djwong@kernel.org, brauner@kernel.org, paulmck@kernel.org, tytso@mit.edu Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-bcache@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-btrfs@vger.kernel.org, Qi Zheng Subject: [PATCH 11/29] virtio_balloon: dynamically allocate the virtio-balloon shrinker Date: Thu, 22 Jun 2023 16:53:17 +0800 Message-Id: <20230622085335.77010-12-zhengqi.arch@bytedance.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: <20230622085335.77010-1-zhengqi.arch@bytedance.com> References: <20230622085335.77010-1-zhengqi.arch@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In preparation for implementing lockless slab shrink, we need to dynamically allocate the virtio-balloon shrinker, so that it can be freed asynchronously using kfree_rcu(). Then it doesn't need to wait for RCU read-side critical section when releasing the struct virtio_balloon. Signed-off-by: Qi Zheng --- drivers/virtio/virtio_balloon.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloo= n.c index 5b15936a5214..fa051bff8d90 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -111,7 +111,7 @@ struct virtio_balloon { struct virtio_balloon_stat stats[VIRTIO_BALLOON_S_NR]; =20 /* Shrinker to return free pages - VIRTIO_BALLOON_F_FREE_PAGE_HINT */ - struct shrinker shrinker; + struct shrinker *shrinker; =20 /* OOM notifier to deflate on OOM - VIRTIO_BALLOON_F_DEFLATE_ON_OOM */ struct notifier_block oom_nb; @@ -816,8 +816,7 @@ static unsigned long shrink_free_pages(struct virtio_ba= lloon *vb, static unsigned long virtio_balloon_shrinker_scan(struct shrinker *shrinke= r, struct shrink_control *sc) { - struct virtio_balloon *vb =3D container_of(shrinker, - struct virtio_balloon, shrinker); + struct virtio_balloon *vb =3D shrinker->private_data; =20 return shrink_free_pages(vb, sc->nr_to_scan); } @@ -825,8 +824,7 @@ static unsigned long virtio_balloon_shrinker_scan(struc= t shrinker *shrinker, static unsigned long virtio_balloon_shrinker_count(struct shrinker *shrink= er, struct shrink_control *sc) { - struct virtio_balloon *vb =3D container_of(shrinker, - struct virtio_balloon, shrinker); + struct virtio_balloon *vb =3D shrinker->private_data; =20 return vb->num_free_page_blocks * VIRTIO_BALLOON_HINT_BLOCK_PAGES; } @@ -847,16 +845,24 @@ static int virtio_balloon_oom_notify(struct notifier_= block *nb, =20 static void virtio_balloon_unregister_shrinker(struct virtio_balloon *vb) { - unregister_shrinker(&vb->shrinker); + unregister_and_free_shrinker(vb->shrinker); } =20 static int virtio_balloon_register_shrinker(struct virtio_balloon *vb) { - vb->shrinker.scan_objects =3D virtio_balloon_shrinker_scan; - vb->shrinker.count_objects =3D virtio_balloon_shrinker_count; - vb->shrinker.seeks =3D DEFAULT_SEEKS; + int ret; + + vb->shrinker =3D shrinker_alloc_and_init(virtio_balloon_shrinker_count, + virtio_balloon_shrinker_scan, + 0, DEFAULT_SEEKS, 0, vb); + if (!vb->shrinker) + return -ENOMEM; + + ret =3D register_shrinker(vb->shrinker, "virtio-balloon"); + if (ret) + shrinker_free(vb->shrinker); =20 - return register_shrinker(&vb->shrinker, "virtio-balloon"); + return ret; } =20 static int virtballoon_probe(struct virtio_device *vdev) --=20 2.30.2