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Message-ID: <e7204276-9de5-17eb-90ae-e51657d73ef4@linux.dev>
Date:   Wed, 26 Jul 2023 14:49:05 +0800
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Subject: Re: [PATCH v2 11/47] gfs2: dynamically allocate the gfs2-qd shrinker
To:     Qi Zheng <zhengqi.arch@bytedance.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org,
        kvm@vger.kernel.org, xen-devel@lists.xenproject.org,
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        vbabka@suse.cz, roman.gushchin@linux.dev, djwong@kernel.org,
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References: <20230724094354.90817-1-zhengqi.arch@bytedance.com>
 <20230724094354.90817-12-zhengqi.arch@bytedance.com>
From:   Muchun Song <muchun.song@linux.dev>
In-Reply-To: <20230724094354.90817-12-zhengqi.arch@bytedance.com>
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On 2023/7/24 17:43, Qi Zheng wrote:
> Use new APIs to dynamically allocate the gfs2-qd shrinker.
>
> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
> ---
>   fs/gfs2/main.c  |  6 +++---
>   fs/gfs2/quota.c | 26 ++++++++++++++++++++------
>   fs/gfs2/quota.h |  3 ++-
>   3 files changed, 25 insertions(+), 10 deletions(-)
>
> diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
> index afcb32854f14..e47b1cc79f59 100644
> --- a/fs/gfs2/main.c
> +++ b/fs/gfs2/main.c
> @@ -147,7 +147,7 @@ static int __init init_gfs2_fs(void)
>   	if (!gfs2_trans_cachep)
>   		goto fail_cachep8;
>   
> -	error = register_shrinker(&gfs2_qd_shrinker, "gfs2-qd");
> +	error = gfs2_qd_shrinker_init();
>   	if (error)
>   		goto fail_shrinker;
>   
> @@ -196,7 +196,7 @@ static int __init init_gfs2_fs(void)
>   fail_wq2:
>   	destroy_workqueue(gfs_recovery_wq);
>   fail_wq1:
> -	unregister_shrinker(&gfs2_qd_shrinker);
> +	gfs2_qd_shrinker_exit();
>   fail_shrinker:
>   	kmem_cache_destroy(gfs2_trans_cachep);
>   fail_cachep8:
> @@ -229,7 +229,7 @@ static int __init init_gfs2_fs(void)
>   
>   static void __exit exit_gfs2_fs(void)
>   {
> -	unregister_shrinker(&gfs2_qd_shrinker);
> +	gfs2_qd_shrinker_exit();
>   	gfs2_glock_exit();
>   	gfs2_unregister_debugfs();
>   	unregister_filesystem(&gfs2_fs_type);
> diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
> index 704192b73605..bc9883cea847 100644
> --- a/fs/gfs2/quota.c
> +++ b/fs/gfs2/quota.c
> @@ -186,13 +186,27 @@ static unsigned long gfs2_qd_shrink_count(struct shrinker *shrink,
>   	return vfs_pressure_ratio(list_lru_shrink_count(&gfs2_qd_lru, sc));
>   }
>   
> -struct shrinker gfs2_qd_shrinker = {
> -	.count_objects = gfs2_qd_shrink_count,
> -	.scan_objects = gfs2_qd_shrink_scan,
> -	.seeks = DEFAULT_SEEKS,
> -	.flags = SHRINKER_NUMA_AWARE,
> -};
> +static struct shrinker *gfs2_qd_shrinker;
> +
> +int gfs2_qd_shrinker_init(void)

It's better to declare this as __init.

> +{
> +	gfs2_qd_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE, "gfs2-qd");
> +	if (!gfs2_qd_shrinker)
> +		return -ENOMEM;
> +
> +	gfs2_qd_shrinker->count_objects = gfs2_qd_shrink_count;
> +	gfs2_qd_shrinker->scan_objects = gfs2_qd_shrink_scan;
> +	gfs2_qd_shrinker->seeks = DEFAULT_SEEKS;
> +
> +	shrinker_register(gfs2_qd_shrinker);
>   
> +	return 0;
> +}
> +
> +void gfs2_qd_shrinker_exit(void)
> +{
> +	shrinker_unregister(gfs2_qd_shrinker);
> +}
>   
>   static u64 qd2index(struct gfs2_quota_data *qd)
>   {
> diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h
> index 21ada332d555..f9cb863373f7 100644
> --- a/fs/gfs2/quota.h
> +++ b/fs/gfs2/quota.h
> @@ -59,7 +59,8 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip,
>   }
>   
>   extern const struct quotactl_ops gfs2_quotactl_ops;
> -extern struct shrinker gfs2_qd_shrinker;
> +int gfs2_qd_shrinker_init(void);
> +void gfs2_qd_shrinker_exit(void);
>   extern struct list_lru gfs2_qd_lru;
>   extern void __init gfs2_quota_hash_init(void);
>