From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Fastabend <john.fastabend@gmail.com>,
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: Fri, 14 Mar 2014 11:50:05 -0700 [thread overview]
Message-ID: <20140314185005.GA17041@linux.vnet.ibm.com> (raw)
In-Reply-To: <20140314153810.GX21124@linux.vnet.ibm.com>
On Fri, Mar 14, 2014 at 08:38:10AM -0700, Paul E. McKenney wrote:
> On Fri, Mar 14, 2014 at 06:46:38AM -0700, Eric Dumazet wrote:
> > On Fri, 2014-03-14 at 06:28 -0700, Paul E. McKenney wrote:
> >
> > > Now I just need to figure out why it -causes- a BUILD_BUG_ON for the
> > > cris and m68k architectures in Fengguang Wu's testing...
> >
> > Right, they don't necessarily align pointers ;)
> >
> > alignof(void *) ?
>
> It complained about the size rather than the alignment, but it would
> certainly make sense to constrain the rcu_head structure's alignment,
> now that you mention it. I will do that and see if it helps. ;-)
>
> Thank you for the tip!
And you were quite right... When the alignment is bad, it complains
about the size. And although I can specify that struct rcu_head be
aligned, but __attribute__(packed) overrides this when specified on an
enclosing structure. As does the -fpack-struct gcc command-line option.
Other thoughts on getting around this problem?
Hmmm... Maybe if cris and m68k guaranteed to keep functions out of the
bottom four pages of memory...
Thanx, Paul
next prev parent reply other threads:[~2014-03-14 18:50 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
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 [this message]
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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