From: Brenden Blanco <bblanco@plumgrid.com>
To: Tom Herbert <tom@herbertland.com>
Cc: Tariq Toukan <tariqt@mellanox.com>,
"David S. Miller" <davem@davemloft.net>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Tariq Toukan <ttoukan.linux@gmail.com>,
Or Gerlitz <gerlitz.or@gmail.com>
Subject: Re: [PATCH] net/mlx4_en: protect ring->xdp_prog with rcu_read_lock
Date: Fri, 2 Sep 2016 11:13:53 -0700 [thread overview]
Message-ID: <20160902181352.GC14176@gmail.com> (raw)
In-Reply-To: <CALx6S34nt0iLEse45y4UrJFbfBFNoZ6oYzu+3Hdq3A=6Rn9hrg@mail.gmail.com>
On Mon, Aug 29, 2016 at 10:46:38AM -0700, Tom Herbert wrote:
[...]
> Brenden, tracking down how the structure is freed needed a few steps,
> please make sure the RCU requirements are well documented. Also, I'm
Really? It's just bpf_prog_put->call_rcu(__bpf_prog_put_rcu). I suppose
what's missing is a general guideline for which functions new consumers
of bpf should use, but I wouldn't trust myself to write such holistic
documentation accurately (e.g. interacting with nmi probes and such).
> still not a fan of using xchg to set the program, seems that a lock
> could be used in that path.
Where would such a lock go? Everything in mlx4/en_netdev.c relies on
rtnl, which seems sufficient and obvious...adding some new field
specific lock would be distracting and unneeded.
>
> Thanks,
> Tom
next prev parent reply other threads:[~2016-09-02 18:13 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-26 20:38 [PATCH] net/mlx4_en: protect ring->xdp_prog with rcu_read_lock Brenden Blanco
2016-08-26 21:01 ` Brenden Blanco
2016-08-29 14:59 ` Tariq Toukan
2016-08-29 15:55 ` Brenden Blanco
2016-08-29 17:46 ` Tom Herbert
2016-08-30 9:35 ` Saeed Mahameed
2016-08-31 1:50 ` Brenden Blanco
2016-09-01 22:59 ` Saeed Mahameed
2016-09-01 23:30 ` Tom Herbert
2016-09-02 17:50 ` Brenden Blanco
2016-09-02 18:01 ` Brenden Blanco
2016-09-02 18:13 ` Brenden Blanco [this message]
2016-09-02 19:14 ` Tom Herbert
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