From: John Ousterhout <ouster@cs.stanford.edu>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev@vger.kernel.org
Subject: Re: BUG: sk_backlog.len can overestimate
Date: Tue, 1 Oct 2019 16:01:41 -0700 [thread overview]
Message-ID: <CAGXJAmyKLQR9Oa9KGPQ9cwYb2sYn-ZAcQa_fVdcunZtKpPRYjg@mail.gmail.com> (raw)
In-Reply-To: <f572890a-ca31-e01a-e370-c8b3e3b51f5b@gmail.com>
On Tue, Oct 1, 2019 at 1:53 PM Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
> On 10/1/19 1:45 PM, John Ousterhout wrote:
>
> >
> > But this isn't really about socket resource limits (though that is
> > conflated in the implementation); it's about limiting the time spent
> > in a single call to __release_sock, no?
>
> The proxy used is memory usage, not time usage.
I apologize for being pedantic, but the proxy isn't memory usage; it's
actually "number of bytes added to the backlog since the last time it
was emptied". At the time the limit is hit, actual memory usage is
probably a lot less than the limit. This was the source of my
confusion, since I assumed you really *wanted* memory usage to be the
limit.
> cond_resched() or a preemptible kernel makes anything based on time flaky,
> you probably do not want to play with a time limit...
>
>
>
prev parent reply other threads:[~2019-10-01 23:02 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAGXJAmwQw1ohc48NfAvMyNDpDgHGkdVO89Jo8B0j0TuMr7wLpA@mail.gmail.com>
2019-09-30 23:58 ` BUG: sk_backlog.len can overestimate John Ousterhout
2019-10-01 0:14 ` Eric Dumazet
2019-10-01 15:44 ` John Ousterhout
[not found] ` <CAGXJAmxmJ-Vm379N4nbjXeQCAgY9ur53wmr0HZy23dQ_t++r-Q@mail.gmail.com>
[not found] ` <f4520c32-3133-fb3b-034e-d492d40eb066@gmail.com>
2019-10-01 15:46 ` Fwd: " John Ousterhout
2019-10-01 15:48 ` John Ousterhout
2019-10-01 16:19 ` Eric Dumazet
2019-10-01 17:25 ` John Ousterhout
2019-10-01 18:34 ` Eric Dumazet
2019-10-01 20:45 ` John Ousterhout
2019-10-01 20:53 ` Eric Dumazet
2019-10-01 23:01 ` John Ousterhout [this message]
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