From: SeongJae Park <sjpark@amazon.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: SeongJae Park <sjpark@amazon.com>, <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: Thu, 10 Dec 2020 07:43:29 +0100 [thread overview]
Message-ID: <20201210064329.6884-1-sjpark@amazon.com> (raw)
In-Reply-To: <20201209151659.125b43da@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com>
On Wed, 9 Dec 2020 15:16:59 -0800 Jakub Kicinski <kuba@kernel.org> wrote:
> 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!
Thank you for let me know that. I will send the next version so.
>
> > 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.
Hehe, ok, I will. :)
Thanks,
SeongJae Park
next prev parent reply other threads:[~2020-12-10 6:45 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
2020-12-10 6:43 ` SeongJae Park [this message]
2020-12-10 0:17 ` Eric Dumazet
2020-12-10 7:27 ` SeongJae Park
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