Re: [PATCH 01/17] quota: allocate dquot_hash with kmalloc()

Jan Kara <[email protected]> Mon, 25 May 2026 18:10:00 +0200
Newsgroups org.kernel.vger.linux-nilfs,dev.linux.lists.ocfs2-devel,org.kernel.vger.linux-ext4,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-nfs,org.kvack.linux-mm
Message-ID <xsmgh26s23da43wv6jza3dqrzhbxuetupiykjis2gkaq53yx3j@kttd6p2ba7f6>
On Sat 23-05-26 20:54:13, Mike Rapoport (Microsoft) wrote:
> dquot_init() allocates a single page for dquot_hash with
> __get_free_pages().
> 
> kmalloc() is a better API for such use and it also provides better
> scalability and more debugging possibilities.
> 
> Replace use of __get_free_pages() with kmalloc() and get rid of the order
> variable that remained 0 for more than 20 years.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>

Thanks! I've added this patch to my tree.

								Honza

> ---
>  fs/quota/dquot.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
> index 64cf42721496..9850de3955d3 100644
> --- a/fs/quota/dquot.c
> +++ b/fs/quota/dquot.c
> @@ -3022,7 +3022,7 @@ static const struct ctl_table fs_dqstats_table[] = {
>  static int __init dquot_init(void)
>  {
>  	int i, ret;
> -	unsigned long nr_hash, order;
> +	unsigned long nr_hash;
>  	struct shrinker *dqcache_shrinker;
>  
>  	printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
> @@ -3035,8 +3035,7 @@ static int __init dquot_init(void)
>  				SLAB_PANIC),
>  			NULL);
>  
> -	order = 0;
> -	dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order);
> +	dquot_hash = kmalloc(PAGE_SIZE, GFP_KERNEL);
>  	if (!dquot_hash)
>  		panic("Cannot create dquot hash table");
>  
> @@ -3046,7 +3045,7 @@ static int __init dquot_init(void)
>  		panic("Cannot create dquot stat counters");
>  
>  	/* Find power-of-two hlist_heads which can fit into allocation */
> -	nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
> +	nr_hash = PAGE_SIZE / sizeof(struct hlist_head);
>  	dq_hash_bits = ilog2(nr_hash);
>  
>  	nr_hash = 1UL << dq_hash_bits;
> @@ -3054,8 +3053,8 @@ static int __init dquot_init(void)
>  	for (i = 0; i < nr_hash; i++)
>  		INIT_HLIST_HEAD(dquot_hash + i);
>  
> -	pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld,"
> -		" %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order));
> +	pr_info("VFS: Dquot-cache hash table entries: %ld (%ld bytes)\n",
> +		nr_hash, PAGE_SIZE);
>  
>  	dqcache_shrinker = shrinker_alloc(0, "dquota-cache");
>  	if (!dqcache_shrinker)
> 
> -- 
> 2.53.0
> 
-- 
Jan Kara <[email protected]>
SUSE Labs, CR