From: Martin Lau <kafai@fb.com>
To: David Ahern <dsahern@gmail.com>
Cc: Wei Wang <weiwan@google.com>, David Ahern <dsahern@kernel.org>,
"David S . Miller" <davem@davemloft.net>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
"idosch@mellanox.com" <idosch@mellanox.com>,
"saeedm@mellanox.com" <saeedm@mellanox.com>
Subject: Re: [PATCH v2 net-next 4/7] ipv6: Plumb support for nexthop object in a fib6_info
Date: Tue, 4 Jun 2019 00:58:45 +0000 [thread overview]
Message-ID: <20190604005840.tiful44xo34lpf6d@kafai-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <4cdcdf65-4d34-603e-cb21-d649b399d760@gmail.com>
On Mon, Jun 03, 2019 at 05:18:11PM -0600, David Ahern wrote:
> On 6/3/19 5:05 PM, Wei Wang wrote:
> > On Mon, Jun 3, 2019 at 3:35 PM David Ahern <dsahern@gmail.com> wrote:
> >>
> >> On 6/3/19 3:58 PM, Wei Wang wrote:
> >>> Hmm... I am still a bit concerned with the ip6_create_rt_rcu() call.
> >>> If we have a blackholed nexthop, the lookup code here always tries to
> >>> create an rt cache entry for every lookup.
> >>> Maybe we could reuse the pcpu cache logic for this? So we only create
> >>> new dst cache on the CPU if there is no cache created before.
> >>
> >> I'll take a look.
> >>
>
> BTW, I am only updating ip6_pol_route to use pcpu routes for blackhole
> nexthops.
>
> ip6_pol_route_lookup will continue as is. That function does not use
> pcpu routes and will stay as is.
>
I have concern on calling ip6_create_rt_rcu() in general which seems
to trace back to this commit
dec9b0e295f6 ("net/ipv6: Add rt6_info create function for ip6_pol_route_lookup")
This rt is not tracked in pcpu_rt, rt6_uncached_list or exception bucket.
In particular, how to react to NETDEV_UNREGISTER/DOWN like
the rt6_uncached_list_flush_dev() does and calls dev_put()?
The existing callers seem to do dst_release() immediately without
caching it, but still concerning.
next prev parent reply other threads:[~2019-06-04 0:58 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-03 4:08 [PATCH v2 net-next 0/7] net: add struct nexthop to fib{6}_info David Ahern
2019-06-03 4:08 ` [PATCH v2 net-next 1/7] ipv4: Use accessors for fib_info nexthop data David Ahern
2019-06-03 4:08 ` [PATCH v2 net-next 2/7] ipv4: Prepare for fib6_nh from a nexthop object David Ahern
2019-06-03 4:08 ` [PATCH v2 net-next 3/7] ipv4: Plumb support for nexthop object in a fib_info David Ahern
2019-06-03 4:08 ` [PATCH v2 net-next 4/7] ipv6: Plumb support for nexthop object in a fib6_info David Ahern
2019-06-03 18:09 ` Wei Wang
2019-06-03 18:37 ` David Ahern
2019-06-03 20:42 ` David Ahern
2019-06-03 21:58 ` Wei Wang
2019-06-03 22:35 ` David Ahern
2019-06-03 23:05 ` Wei Wang
2019-06-03 23:18 ` David Ahern
2019-06-03 23:30 ` Wei Wang
2019-06-04 0:58 ` Martin Lau [this message]
2019-06-04 1:36 ` David Ahern
2019-06-04 5:29 ` Martin Lau
2019-06-04 20:17 ` David Ahern
2019-06-04 21:06 ` Martin Lau
2019-06-04 21:13 ` David Ahern
2019-06-04 21:36 ` Wei Wang
2019-06-04 23:30 ` David Ahern
2019-06-05 0:39 ` Martin Lau
2019-06-05 2:05 ` David Ahern
2019-06-05 6:01 ` Martin Lau
2019-06-04 21:53 ` Martin Lau
2019-06-03 4:08 ` [PATCH v2 net-next 5/7] mlxsw: Fail attempts to use routes with nexthop objects David Ahern
2019-06-03 4:08 ` [PATCH v2 net-next 6/7] mlx5: " David Ahern
2019-06-03 4:08 ` [PATCH v2 net-next 7/7] rocker: " David Ahern
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