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From: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
To: Stephen Hemminger <shemminger@osdl.org>
Cc: David Miller <davem@davemloft.net>, netdev@vger.kernel.org
Subject: Re: [PATCH 4/6] net neighbour: convert to RCU
Date: Tue, 29 Aug 2006 19:28:16 +0400	[thread overview]
Message-ID: <20060829152816.GA24283@ms2.inr.ac.ru> (raw)
In-Reply-To: <20060828230915.587544687@localhost.localdomain>

Hello!

> @@ -346,8 +354,8 @@ struct neighbour *neigh_lookup(struct ne
>  	
>  	NEIGH_CACHE_STAT_INC(tbl, lookups);
>  
> -	read_lock_bh(&tbl->lock);
> -	hlist_for_each_entry(n, tmp, &tbl->hash_buckets[hash_val], hlist) {
> +	rcu_read_lock();
> +	hlist_for_each_entry_rcu(n, tmp, &tbl->hash_buckets[hash_val], hlist) {
>  		if (dev == n->dev && !memcmp(n->primary_key, pkey, key_len)) {
>  			neigh_hold(n);
>  			NEIGH_CACHE_STAT_INC(tbl, hits);

Sure? Seems, you cannot grab refcnt here, the entry can be already
released.

Probably, you should do atomic_inc_and_test() here and restart lookup,
if it fails.

Alexey

  reply	other threads:[~2006-08-29 15:29 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-08-28 23:07 [PATCH 0/6] Lockless neighbour table Stephen Hemminger
2006-08-28 23:07 ` [PATCH 1/6] net neighbor: convert top level list to RCU Stephen Hemminger
2006-08-28 23:07 ` [PATCH 2/6] neighbour: convert neighbour hash table to hlist Stephen Hemminger
2006-08-28 23:07 ` [PATCH 3/6] neighbour: convert pneigh " Stephen Hemminger
2006-08-28 23:07 ` [PATCH 4/6] net neighbour: convert to RCU Stephen Hemminger
2006-08-29 15:28   ` Alexey Kuznetsov [this message]
2006-08-29 18:22     ` Stephen Hemminger
2006-08-29 18:34       ` Martin Josefsson
2006-08-29 20:17         ` Stephen Hemminger
2006-08-29 21:17       ` Alexey Kuznetsov
2006-08-29 21:46         ` Stephen Hemminger
2006-08-29 22:16           ` Alexey Kuznetsov
2006-08-29 23:00             ` Stephen Hemminger
2006-08-29 23:21               ` Alexey Kuznetsov
2006-08-29 23:49                 ` Stephen Hemminger
2006-08-30  0:06                   ` Alexey Kuznetsov
2006-08-29 23:36               ` Alexey Kuznetsov
2006-08-28 23:07 ` [PATCH 5/6] neighbour: convert lookup to sequence lock Stephen Hemminger
2006-08-28 23:07 ` [PATCH 6/6] neighbour: convert hard header cache to sequence number Stephen Hemminger

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