From: Andi Kleen <andi@firstfloor.org>
To: Nandita Dukkipati <nanditad@google.com>
Cc: "David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, Tom Herbert <therbert@google.com>,
Yuchung Cheng <ycheng@google.com>,
Matt Mathis <mattmathis@google.com>
Subject: Re: [PATCH] Proportional Rate Reduction for TCP.
Date: Sat, 13 Aug 2011 22:05:25 -0700 [thread overview]
Message-ID: <m262m0lh0q.fsf@firstfloor.org> (raw)
In-Reply-To: <1313134197-5082-1-git-send-email-nanditad@google.com> (Nandita Dukkipati's message of "Fri, 12 Aug 2011 00:29:57 -0700")
Nandita Dukkipati <nanditad@google.com> writes:
> +
> + if (tcp_packets_in_flight(tp) > tp->snd_ssthresh) {
> + if (WARN_ON(!tp->prr_cwnd))
> + tp->prr_cwnd = 1;
> + sndcnt = DIV_ROUND_UP(tp->prr_delivered * tp->snd_ssthresh,
> + tp->prr_cwnd) - tp->prr_out;
> + } else {
> + sndcnt = min_t(int, delta,
> + max_t(int, tp->prr_delivered -
> tp->prr_out,
u32s here? This will likely do bad things with large enough windows.
The rest looks good to me as code, but I don't claim to fully understand the
algorithm. Perhaps a sysctl to turn it off and a linux mib counter when
it triggers would be useful in addition.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2011-08-14 5:05 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-12 7:29 [PATCH] Proportional Rate Reduction for TCP Nandita Dukkipati
2011-08-12 11:36 ` Ilpo Järvinen
2011-08-19 7:34 ` Nandita Dukkipati
2011-08-14 5:05 ` Andi Kleen [this message]
2011-08-19 7:34 ` Nandita Dukkipati
2011-08-19 7:33 ` [PATCH v2] " Nandita Dukkipati
2011-08-19 10:25 ` Ilpo Järvinen
2011-08-20 1:28 ` Nandita Dukkipati
2011-08-20 12:41 ` Ilpo Järvinen
2011-08-22 6:21 ` Nandita Dukkipati
2011-08-19 10:26 ` David Miller
2011-08-20 1:29 ` Nandita Dukkipati
2011-08-20 1:29 ` [PATCH v3] " Nandita Dukkipati
2011-08-22 6:21 ` [PATCH v4] " Nandita Dukkipati
2011-08-25 2:43 ` David Miller
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