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From: Lino Sanfilippo <lsanfil@marvell.com>
To: Eric Dumazet <eric.dumazet@gmail.com>,
	David Miller <davem@davemloft.net>
Cc: <pavel@ucw.cz>, <peppe.cavallaro@st.com>,
	<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: stmmac ethernet in kernel 4.4: coalescing related pauses?
Date: Mon, 28 Nov 2016 16:57:35 +0100	[thread overview]
Message-ID: <920b1148-a77d-0b69-01b0-b14bcbdf8648@marvell.com> (raw)
In-Reply-To: <1480347103.18162.58.camel@edumazet-glaptop3.roam.corp.google.com>



On 28.11.2016 16:31, Eric Dumazet wrote:
> On Mon, 2016-11-28 at 09:54 -0500, David Miller wrote:
>> From: Lino Sanfilippo <lsanfil@marvell.com>
>> Date: Mon, 28 Nov 2016 14:07:51 +0100
>>
>>> Calling skb_orphan() in the xmit handler made this issue disappear.
>>
>> This is not the way to handle this problem.
>>
>> The solution is to free the SKBs in a timely manner after the
>> chip has transmitted the frame.
>
> Note that the 'pauses' described by Pavel are also caused by a too small
> SO_SNDBUF value on the UDP socket.
>
> An immediate fix, with no kernel change is to increase it.
>
> echo 1000000 >/proc/sys/net/core/wmem_default
>
> or
>
> val = 1000000;
> setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &val, sizeof(val));
>

I wonder if the best fix would be indeed to deactivate irq coalescing completely.
Does it make any sense at all to use it if a driver uses NAPI already?

Regards,
Lino

  reply	other threads:[~2016-11-28 15:58 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-23 10:51 stmmac ethernet in kernel 4.4: coalescing related pauses? Pavel Machek
2016-11-24  8:55 ` stmmac ethernet in kernel 4.9-rc6: coalescing related pauses Pavel Machek
2016-11-24 10:29   ` Pavel Machek
2016-11-24 10:36     ` Pavel Machek
2016-11-24 10:46       ` [PATCH] stmmac ethernet: unify locking Pavel Machek
2016-11-24 11:05         ` [PATCH] stmmac ethernet: remove cut & paste code Pavel Machek
2016-11-24 20:05           ` Joe Perches
2016-11-24 21:44             ` Pavel Machek
2016-11-24 22:27               ` Joe Perches
2016-11-28 11:50                 ` Pavel Machek
2016-11-28 14:24                   ` Joe Perches
2016-11-28 14:35                     ` Pavel Machek
2016-11-28 16:03                       ` Joe Perches
2016-11-24 16:04   ` stmmac ethernet in kernel 4.9-rc6: coalescing related pauses David Miller
2016-11-24 21:25     ` Pavel Machek
2016-12-02  8:24       ` Giuseppe CAVALLARO
2016-12-02  8:41         ` Giuseppe CAVALLARO
2016-12-02  8:45         ` Pavel Machek
2016-12-02  9:43           ` Giuseppe CAVALLARO
2016-12-02 12:32             ` Pavel Machek
2016-12-02 13:51               ` Giuseppe CAVALLARO
2016-12-02 14:26                 ` Alexandre Torgue
2016-12-02 15:19                   ` Giuseppe CAVALLARO
2016-12-05 12:14                     ` Pavel Machek
2016-12-05 12:01                 ` Pavel Machek
2016-12-05 10:15             ` Pavel Machek
2016-12-05 11:40               ` Lino Sanfilippo
2016-12-05 22:02                 ` Pavel Machek
2016-12-05 22:37                   ` Lino Sanfilippo
2016-12-05 22:40                     ` Pavel Machek
2016-12-05 22:54                       ` Lino Sanfilippo
2016-12-05 23:11                         ` Lino Sanfilippo
2016-12-02 14:05           ` Aw: " Lino Sanfilippo
2016-12-07 12:31             ` [RFC] " Pavel Machek
2016-12-07 13:18               ` Lino Sanfilippo
2016-12-05 11:56         ` Pavel Machek
2016-11-28 11:55     ` [PATCH] stmmac: fix comments, make debug output consistent Pavel Machek
2016-11-30  0:53       ` David Miller
2016-11-28 12:13     ` stmmac ethernet in kernel 4.9-rc6: coalescing related pauses Pavel Machek
2016-11-28 12:17     ` [PATCH] stmmac: reduce code duplication getting basic descriptors Pavel Machek
2016-11-28 15:25       ` kbuild test robot
2016-12-02 14:09       ` Alexandre Torgue
2016-11-30 11:44     ` [PATCH] stmmac: simplify flag assignment Pavel Machek
2016-12-01 20:23       ` David Miller
2016-12-01 22:48         ` stmmac: turn coalescing / NAPI off in stmmac Pavel Machek
2016-12-02  8:39           ` Giuseppe CAVALLARO
2016-12-02 10:42             ` Pavel Machek
2016-12-02 15:31               ` Giuseppe CAVALLARO
2016-12-05 11:45                 ` Pavel Machek
2016-12-02  8:27       ` [PATCH] stmmac: simplify flag assignment Giuseppe CAVALLARO
2016-12-01 10:32     ` [PATCH] stmmac: cleanup documenation, make it match reality Pavel Machek
2016-12-03 20:07       ` David Miller
2016-12-05 12:27     ` [PATCH] stmmac: disable tx coalescing Pavel Machek
2016-12-11 19:07       ` Pavel Machek
2016-12-11 19:31         ` David Miller
2016-12-11 19:57           ` Pavel Machek
2016-11-28 13:07 ` stmmac ethernet in kernel 4.4: coalescing related pauses? Lino Sanfilippo
2016-11-28 14:54   ` David Miller
2016-11-28 15:31     ` Eric Dumazet
2016-11-28 15:57       ` Lino Sanfilippo [this message]
2016-11-28 16:30         ` David Miller
2016-11-28 17:01           ` Lino Sanfilippo
2016-11-30 10:28       ` Pavel Machek
2016-11-28 15:33     ` Lino Sanfilippo

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