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From: Florian Westphal <fw@strlen.de>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Florian Westphal <fw@strlen.de>, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH nf-next 4/6] netfilter: conntrack: add gc worker to remove timed-out entries
Date: Fri, 19 Aug 2016 17:22:20 +0200	[thread overview]
Message-ID: <20160819152220.GB11049@breakpoint.cc> (raw)
In-Reply-To: <1471617673.29842.105.camel@edumazet-glaptop3.roam.corp.google.com>

Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Fri, 2016-08-19 at 13:36 +0200, Florian Westphal wrote:
> > Conntrack gc worker to evict stale entries.
> 
> ...
> 
> > +
> > +		hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[i], hnnode) {
> > +			tmp = nf_ct_tuplehash_to_ctrack(h);
> > +
> > +			if (nf_ct_is_expired(tmp)) {
> > +				nf_ct_gc_expired(tmp);
> > +				expired_count++;
> > +				continue;
> 
> Same remark about hlist_nulls_for_each_entry_rcu() not 'safe' here

Hmm, I am missing something, I will wait for your answer on my previous
reply ...

I though this was safe due to rcu -- another cpu could evict entry as
well so we can always see 'free'd objects with refcnt 0.

(nf_ct_gc_expired() skips those to avoid double-free).

> > +		rcu_read_unlock();
> > +		cond_resched();
> 
> This could use cond_resched_rcu_qs() 

Indeed, I did not kown about this, nice!

Will add it in V2, thanks!


  reply	other threads:[~2016-08-19 15:22 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-19 11:36 [PATCH nf-next 0/6] conntrack: get rid of per-object timer Florian Westphal
2016-08-19 11:36 ` [PATCH nf-next 1/6] netfilter: don't rely on DYING bit to detect when destroy event was sent Florian Westphal
2016-08-19 11:36 ` [PATCH nf-next 2/6] netfilter: conntrack: get rid of conntrack timer Florian Westphal
2016-08-19 14:37   ` Eric Dumazet
2016-08-19 15:16     ` Florian Westphal
2016-08-19 15:24       ` Eric Dumazet
2016-08-19 16:04         ` Florian Westphal
2016-08-22  4:13           ` Eric Dumazet
2016-08-22  8:53             ` Florian Westphal
2016-08-19 11:36 ` [PATCH nf-next 3/6] netfilter: evict stale entries on netlink dumps Florian Westphal
2016-08-19 11:36 ` [PATCH nf-next 4/6] netfilter: conntrack: add gc worker to remove timed-out entries Florian Westphal
2016-08-19 14:41   ` Eric Dumazet
2016-08-19 15:22     ` Florian Westphal [this message]
2016-08-19 11:36 ` [PATCH nf-next 5/6] netfilter: conntrack: resched gc again if eviction rate is high Florian Westphal
2016-08-19 11:36 ` [PATCH nf-next 6/6] netfilter: remove __nf_ct_kill_acct helper Florian Westphal

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