From: Jakub Kicinski <kuba@kernel.org>
To: SeongJae Park <sjpark@amazon.com>
Cc: <davem@davemloft.net>, SeongJae Park <sjpark@amazon.de>,
<kuznet@ms2.inr.ac.ru>, <paulmck@kernel.org>,
<netdev@vger.kernel.org>, <rcu@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] net/ipv4/inet_fragment: Batch fqdir destroy works
Date: Wed, 9 Dec 2020 15:16:59 -0800 [thread overview]
Message-ID: <20201209151659.125b43da@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> (raw)
In-Reply-To: <20201208094529.23266-2-sjpark@amazon.com>
On Tue, 8 Dec 2020 10:45:29 +0100 SeongJae Park wrote:
> From: SeongJae Park <sjpark@amazon.de>
>
> In 'fqdir_exit()', a work for destruction of the 'fqdir' is enqueued.
> The work function, 'fqdir_work_fn()', calls 'rcu_barrier()'. In case of
> intensive 'fqdir_exit()' (e.g., frequent 'unshare(CLONE_NEWNET)'
> systemcalls), this increased contention could result in unacceptably
> high latency of 'rcu_barrier()'. This commit avoids such contention by
> doing the destruction in batched manner, as similar to that of
> 'cleanup_net()'.
>
> Signed-off-by: SeongJae Park <sjpark@amazon.de>
Looks fine to me, but you haven't CCed Florian or Eric who where the
last two people to touch this function. Please repost CCing them and
fixing the nit below, thanks!
> static void fqdir_work_fn(struct work_struct *work)
> {
> - struct fqdir *fqdir = container_of(work, struct fqdir, destroy_work);
> - struct inet_frags *f = fqdir->f;
> + struct llist_node *kill_list;
> + struct fqdir *fqdir;
> + struct inet_frags *f;
nit: reorder fqdir and f to keep reverse xmas tree variable ordering.
next prev parent reply other threads:[~2020-12-09 23:18 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-08 9:45 [PATCH 0/1] net: Reduce rcu_barrier() contentions from 'unshare(CLONE_NEWNET)' SeongJae Park
2020-12-08 9:45 ` [PATCH 1/1] net/ipv4/inet_fragment: Batch fqdir destroy works SeongJae Park
2020-12-09 23:16 ` Jakub Kicinski [this message]
2020-12-10 6:43 ` SeongJae Park
2020-12-10 0:17 ` Eric Dumazet
2020-12-10 7:27 ` SeongJae Park
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