From patchwork Thu Jun 22 08:39:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qi Zheng X-Patchwork-Id: 13288525 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 4163AEB64DC for ; Thu, 22 Jun 2023 08:42:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231166AbjFVImj (ORCPT ); Thu, 22 Jun 2023 04:42:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231143AbjFVImI (ORCPT ); Thu, 22 Jun 2023 04:42:08 -0400 Received: from out-18.mta1.migadu.com (out-18.mta1.migadu.com [IPv6:2001:41d0:203:375::12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF5EC210C for ; Thu, 22 Jun 2023 01:41:21 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1687423279; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HcTjqzLQd71ZVb4pzslJvUSmaexvFgNd/hk+/QuqHC8=; b=sVEpWPhmhMKCP77bE/ObQ4vh36qd8p86S9YTJ/PP2t7O5H1rqOFnAADJATnE/Im2pGl6K+ faUcWupfoFI2g9i9atXE0VwhccNnX7/0UsnRt6J1CWpSBlTlvvvrCKJ9m/IyCeNWLYDiY/ S/WTlid4FLB0IXUx+GwQRgK3ap17RFE= 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, freedreno@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 08:39:14 +0000 Message-Id: <20230622083932.4090339-12-qi.zheng@linux.dev> In-Reply-To: <20230622083932.4090339-1-qi.zheng@linux.dev> References: <20230622083932.4090339-1-qi.zheng@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Qi Zheng 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_balloon.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]; /* Shrinker to return free pages - VIRTIO_BALLOON_F_FREE_PAGE_HINT */ - struct shrinker shrinker; + struct shrinker *shrinker; /* 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_balloon *vb, static unsigned long virtio_balloon_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) { - struct virtio_balloon *vb = container_of(shrinker, - struct virtio_balloon, shrinker); + struct virtio_balloon *vb = shrinker->private_data; return shrink_free_pages(vb, sc->nr_to_scan); } @@ -825,8 +824,7 @@ static unsigned long virtio_balloon_shrinker_scan(struct shrinker *shrinker, static unsigned long virtio_balloon_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) { - struct virtio_balloon *vb = container_of(shrinker, - struct virtio_balloon, shrinker); + struct virtio_balloon *vb = shrinker->private_data; 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, static void virtio_balloon_unregister_shrinker(struct virtio_balloon *vb) { - unregister_shrinker(&vb->shrinker); + unregister_and_free_shrinker(vb->shrinker); } static int virtio_balloon_register_shrinker(struct virtio_balloon *vb) { - vb->shrinker.scan_objects = virtio_balloon_shrinker_scan; - vb->shrinker.count_objects = virtio_balloon_shrinker_count; - vb->shrinker.seeks = DEFAULT_SEEKS; + int ret; + + vb->shrinker = shrinker_alloc_and_init(virtio_balloon_shrinker_count, + virtio_balloon_shrinker_scan, + 0, DEFAULT_SEEKS, 0, vb); + if (!vb->shrinker) + return -ENOMEM; + + ret = register_shrinker(vb->shrinker, "virtio-balloon"); + if (ret) + shrinker_free(vb->shrinker); - return register_shrinker(&vb->shrinker, "virtio-balloon"); + return ret; } static int virtballoon_probe(struct virtio_device *vdev)