From: John Fastabend <john.fastabend@gmail•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: xiyou.wangcong@gmail•com, jhs@mojatatu•com,
netdev@vger•kernel.org, davem@davemloft•net
Subject: Re: [RCU PATCH 06/14] net: sched: fw use RCU
Date: Wed, 12 Mar 2014 09:41:35 -0700 [thread overview]
Message-ID: <53208E3F.5090401@gmail.com> (raw)
In-Reply-To: <1394473279.3607.46.camel@edumazet-glaptop2.roam.corp.google.com>
On 03/10/2014 10:41 AM, Eric Dumazet wrote:
> On Mon, 2014-03-10 at 10:05 -0700, John Fastabend wrote:
>> RCU'ify fw classifier.
>>
>> Signed-off-by: John Fastabend <john.r.fastabend@intel•com>
>> ---
>> net/sched/cls_fw.c | 110 ++++++++++++++++++++++++++++++++++++----------------
>> 1 file changed, 76 insertions(+), 34 deletions(-)
>>
>> diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
>> index a366537..ff392f1 100644
>> --- a/net/sched/cls_fw.c
>> +++ b/net/sched/cls_fw.c
>> @@ -32,18 +32,21 @@
>> #define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
>>
>> struct fw_head {
>> - struct fw_filter *ht[HTSIZE];
>> + struct rcu_head rcu;
>
> Try to put 'rcu' at the end of structures, we do not need it in fast
> path.
>
>> + struct fw_filter __rcu *ht[HTSIZE];
>> u32 mask;
>> };
>>
>> struct fw_filter {
>> - struct fw_filter *next;
>> + struct fw_filter __rcu *next;
>> + struct rcu_head rcu;
>
> same remark
>
[...]
>>
>> @@ -150,29 +159,32 @@ static void fw_destroy(struct tcf_proto *tp)
>> return;
>>
>> for (h = 0; h < HTSIZE; h++) {
>> - while ((f = head->ht[h]) != NULL) {
>> - head->ht[h] = f->next;
>> - fw_delete_filter(tp, f);
>> + while ((f = rtnl_dereference(head->ht[h])) != NULL) {
>> + rcu_assign_pointer(head->ht[h],
>> + rtnl_dereference(f->next));
>> + call_rcu(&f->rcu, fw_delete_filter);
>> }
>> }
>> - kfree(head);
>> + rcu_assign_pointer(tp->root, NULL);
>
> RCU_INIT_POINTER
>
>> + kfree_rcu(head, rcu);
Rearranging the rcu_head placement above results in this error:
net/sched/cls_fw.c: In function ‘fw_destroy’:
net/sched/cls_fw.c:169:279: error: call to ‘__compiletime_assert_169’
declared with attribute error: BUILD_BUG_ON failed:
!__is_kfree_rcu_offset(__builtin_offsetof(typeof(*(head)),rcu))
However it seems best to have the rcu_head at the end of the struct
so I'll just convert the kfree_rcu() to call_rcu().
Thanks,
John
--
John Fastabend Intel Corporation
next prev parent reply other threads:[~2014-03-12 16:41 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-10 17:03 [RCU PATCH 00/14] Remove qdisc lock around ingress Qdisc John Fastabend
2014-03-10 17:03 ` [RCU PATCH 01/14] net: qdisc: use rcu prefix and silence sparse warnings John Fastabend
2014-03-10 17:20 ` Eric Dumazet
2014-03-10 17:04 ` [RCU PATCH 02/14] net: rcu-ify tcf_proto John Fastabend
2014-03-10 17:30 ` Eric Dumazet
2014-03-10 17:04 ` [RCU PATCH 03/14] net: sched: cls_basic use RCU John Fastabend
2014-03-10 17:33 ` Eric Dumazet
2014-03-10 17:04 ` [RCU PATCH 04/14] net: sched: cls_cgroup " John Fastabend
2014-03-10 17:36 ` Eric Dumazet
2014-03-10 17:05 ` [RCU PATCH 05/14] net: sched: cls_flow " John Fastabend
2014-03-10 17:38 ` Eric Dumazet
2014-03-10 17:05 ` [RCU PATCH 06/14] net: sched: fw " John Fastabend
2014-03-10 17:41 ` Eric Dumazet
2014-03-12 16:41 ` John Fastabend [this message]
2014-03-12 17:01 ` Eric Dumazet
2014-03-13 20:22 ` Paul E. McKenney
2014-03-13 20:56 ` Eric Dumazet
2014-03-13 21:15 ` Paul E. McKenney
2014-03-14 5:43 ` John Fastabend
2014-03-14 13:28 ` Paul E. McKenney
2014-03-14 13:46 ` Eric Dumazet
2014-03-14 15:38 ` Paul E. McKenney
2014-03-14 18:50 ` Paul E. McKenney
2014-03-14 18:59 ` Paul E. McKenney
2014-03-14 19:55 ` Eric Dumazet
2014-03-14 20:35 ` Paul E. McKenney
2014-03-16 16:06 ` [PATCH net-next] net: sched: use no more than one page in struct fw_head Eric Dumazet
2014-03-17 13:51 ` Thomas Graf
2014-03-17 14:13 ` Eric Dumazet
2014-03-17 14:29 ` David Laight
2014-03-17 15:16 ` Eric Dumazet
2014-03-17 15:30 ` Thomas Graf
2014-03-17 15:33 ` Eric Dumazet
2014-03-17 15:43 ` David Laight
2014-03-17 15:52 ` Eric Dumazet
2014-03-17 15:28 ` Thomas Graf
2014-03-17 15:50 ` Thomas Graf
2014-03-17 16:00 ` David Laight
2014-03-17 16:16 ` Eric Dumazet
2014-03-18 2:31 ` David Miller
2014-03-18 3:02 ` Eric Dumazet
2014-03-18 3:20 ` [PATCH v2 " Eric Dumazet
2014-03-18 9:19 ` Thomas Graf
2014-03-18 18:18 ` David Miller
2014-03-10 17:06 ` [RCU PATCH 07/14] net: sched: RCU cls_route John Fastabend
2014-03-10 17:45 ` Eric Dumazet
2014-03-10 19:36 ` John Fastabend
2014-03-10 17:06 ` [RCU PATCH 08/14] net: sched: RCU cls_tcindex John Fastabend
2014-03-10 17:07 ` [RCU PATCH 09/14] net: sched: make cls_u32 lockless John Fastabend
2014-03-10 17:58 ` Eric Dumazet
2014-03-10 17:07 ` [RCU PATCH 10/14] net: sched: rcu'ify cls_rsvp John Fastabend
2014-03-10 17:07 ` [RCU PATCH 11/14] net: make cls_bpf rcu safe John Fastabend
2014-03-10 17:08 ` [RCU PATCH 12/14] net: sched: make tc_action safe to walk under RCU John Fastabend
2014-03-10 17:08 ` [RCU PATCH 13/14] net: sched: make bstats per cpu and estimator RCU safe John Fastabend
2014-03-10 18:06 ` Eric Dumazet
2014-03-10 19:36 ` John Fastabend
2014-03-10 17:09 ` [RCU PATCH 14/14] net: sched: drop ingress qdisc lock John Fastabend
2014-03-11 20:36 ` [RCU PATCH 00/14] Remove qdisc lock around ingress Qdisc David Miller
2014-03-11 20:53 ` Eric Dumazet
2014-03-12 6:58 ` Jamal Hadi Salim
2014-03-12 16:45 ` John Fastabend
2014-03-13 8:44 ` Jamal Hadi Salim
2014-03-14 7:28 ` John Fastabend
2014-03-14 7:45 ` Jamal Hadi Salim
2014-03-12 18:25 ` Cong Wang
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