From: Al Viro <viro@ZenIV.linux.org.uk>
To: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: netdev@vger.kernel.org, Cong Wang <xiyou.wangcong@gmail.com>,
Jiri Pirko <jiri@resnulli.us>
Subject: Re: [PATCH net 00/13] cls_u32 cleanups and fixes.
Date: Sun, 9 Sep 2018 15:15:38 +0100 [thread overview]
Message-ID: <20180909141538.GG19965@ZenIV.linux.org.uk> (raw)
In-Reply-To: <5f835727-3f86-1532-889f-d11ae17e16d4@mojatatu.com>
On Sun, Sep 09, 2018 at 08:58:50AM -0400, Jamal Hadi Salim wrote:
>
> Since you have the momentum here: i noticed something
> unusual while i was trying to craft a test that would
> vet some of your changes. This has nothing to do with
> your changes, same happens on my stock debian laptop
> with kernel:
> 4.17.0-0.bpo.3-amd64 #1 SMP Debian 4.17.17-1~bpo9+1 (2018-08-27)
>
> Looking at git - possibly introduced around the time u32
> lockless was being introduced and maybe even earlier
> than that.
It's always been that way, actually - before that point the old
knode simply got reused, which excluded any chance of changing
n->sel.
> Unfortunately i dont have time to dig
> further.
>
> To reproduce what i am referring to, here's a setup:
>
> $tc filter add dev eth0 parent ffff: protocol ip prio 102 u32 \
> classid 1:2 match ip src 192.168.8.0/8
> $tc filter replace dev eth0 parent ffff: protocol ip prio 102 \
> handle 800:0:800 u32 classid 1:2 match ip src 1.1.0.0/24
>
> u32_change() code path should have allowed changing of the
> keynode.
Umm... Interesting - TCA_U32_SEL is not the only thing that
gets ignored there; TCA_U32_MARK gets the same treatment.
And then there's a lovely question what to do with n->pf -
it's an array of n->sel.nkeys counters, and apparently we
want (at least in common cases) to avoid resetting those.
*If* we declare that ->nkeys mismatch means failure, it's
all relatively easy to implement. Alternatively, we could
declare that selector change means resetting the stats.
Preferences?
next prev parent reply other threads:[~2018-09-09 19:05 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-09 1:31 [PATCH net 00/13] cls_u32 cleanups and fixes Al Viro
2018-09-09 1:31 ` [PATCH net 01/13] net: sched: cls_u32: fix hnode refcounting Al Viro
2018-09-09 11:37 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 02/13] net: sched: cls_u32: mark root hnode explicitly Al Viro
2018-09-09 11:39 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 03/13] net: sched: cls_u32: disallow linking to root hnode Al Viro
2018-09-09 11:39 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 04/13] net: sched: cls_u32: make sure that divisor is a power of 2 Al Viro
2018-09-09 11:41 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 05/13] net: sched: cls_u32: get rid of unused argument of u32_destroy_key() Al Viro
2018-09-09 11:41 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 06/13] net: sched: cls_u32: get rid of tc_u_knode ->tp Al Viro
2018-09-09 11:43 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 07/13] net: sched: cls_u32: get rid of tc_u_common ->rcu Al Viro
2018-09-09 11:45 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 08/13] net: sched: cls_u32: clean tc_u_common hashtable Al Viro
2018-09-09 11:47 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 09/13] net: sched: cls_u32: pass tc_u_common to u32_set_parms() instead of tc_u_hnode Al Viro
2018-09-09 11:52 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 10/13] net: sched: cls_u32: the tp_c argument of u32_set_parms() is always tp->data Al Viro
2018-09-09 12:48 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 11/13] net: sched: cls_u32: get rid of hnode ->tp_c and tp_c argument of u32_set_parms() Al Viro
2018-09-09 12:49 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 12/13] net: sched: cls_u32: keep track of knodes count in tc_u_common Al Viro
2018-09-09 12:50 ` Jamal Hadi Salim
2018-09-09 1:31 ` [PATCH net 13/13] net: sched: cls_u32: simplify the hell out u32_delete() emptiness check Al Viro
2018-09-09 12:51 ` Jamal Hadi Salim
2018-09-09 12:58 ` [PATCH net 00/13] cls_u32 cleanups and fixes Jamal Hadi Salim
2018-09-09 14:15 ` Al Viro [this message]
2018-09-09 15:48 ` Al Viro
2018-09-10 12:25 ` Offloaded u32 classifier tables WAS (Re: " Jamal Hadi Salim
2018-09-10 12:31 ` Jamal Hadi Salim
2018-09-10 11:30 ` Jamal Hadi Salim
2018-09-12 6:15 ` David Miller
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