linux-kernel - Re: [PATCH 2/2] kfree_rcu() should use kfree

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180403205822.GB30145@bombadil.infradead.org>
Date:   Tue, 3 Apr 2018 13:58:22 -0700
From:   Matthew Wilcox <willy@...radead.org>
To:     rao.shoaib@...cle.com
Cc:     linux-kernel@...r.kernel.org, paulmck@...ux.vnet.ibm.com,
        joe@...ches.com, brouer@...hat.com, linux-mm@...ck.org
Subject: Re: [PATCH 2/2] kfree_rcu() should use kfree_bulk() interface

On Tue, Apr 03, 2018 at 10:22:53AM -0700, rao.shoaib@...cle.com wrote:
> +++ b/mm/slab.h
> @@ -80,6 +80,29 @@ extern const struct kmalloc_info_struct {
>  	unsigned long size;
>  } kmalloc_info[];
>  
> +#define	RCU_MAX_ACCUMULATE_SIZE	25
> +
> +struct rcu_bulk_free_container {
> +	struct	rcu_head rbfc_rcu;
> +	int	rbfc_entries;
> +	void	*rbfc_data[RCU_MAX_ACCUMULATE_SIZE];
> +	struct	rcu_bulk_free *rbfc_rbf;
> +};
> +
> +struct rcu_bulk_free {
> +	struct	rcu_head rbf_rcu; /* used to schedule monitor process */
> +	spinlock_t	rbf_lock;
> +	struct		rcu_bulk_free_container *rbf_container;
> +	struct		rcu_bulk_free_container *rbf_cached_container;
> +	struct		rcu_head *rbf_list_head;
> +	int		rbf_list_size;
> +	int		rbf_cpu;
> +	int		rbf_empty;
> +	int		rbf_polled;
> +	bool		rbf_init;
> +	bool		rbf_monitor;
> +};

I think you might be better off with an IDR.  The IDR can always
contain one entry, so there's no need for this 'rbf_list_head' or
__rcu_bulk_schedule_list.  The IDR contains its first 64 entries in
an array (if that array can be allocated), so it's compatible with the
kfree_bulk() interface.