All of lore.kernel.org
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Alexander Duyck <alexander.duyck@gmail.com>
Cc: netdev <netdev@vger.kernel.org>, Alexander Duyck <aduyck@mirantis.com>
Subject: Re: [RFC] net: remove busylock
Date: Thu, 19 May 2016 12:35:23 -0700	[thread overview]
Message-ID: <1463686523.18194.232.camel@edumazet-glaptop3.roam.corp.google.com> (raw)
In-Reply-To: <1463684190.18194.228.camel@edumazet-glaptop3.roam.corp.google.com>

On Thu, 2016-05-19 at 11:56 -0700, Eric Dumazet wrote:

> Removing busylock helped in all cases I tested. (at least on x86 as
> David pointed out)
> 
> As I said, we need to revisit busylock now that spinlocks are different.
> 
> In one case (20 concurrent UDP netperf), I even got a 500 % increase.
> 
> With busylock :
> 
> lpaa5:~# sar -n DEV 4 4|grep eth0
> Average:         eth0     12.19 112797.12      1.95  37672.28      0.00      0.00      0.69
> 


Hmpf, my sysctl logic was inverted. Really these results made little
sense.

Sorry for the noise. At least we have 8% confirmed gain with this
stuff ;)

> Presumably it would tremendously help if the actual kfree_skb()
> was done after qdisc lock is released, ie not from the qdisc->enqueue()
> method.
> 

This part is still valid.

We could have a per cpu storage of one skb pointer, so that we do not
have to change all ->enqueue() prototypes.

  reply	other threads:[~2016-05-19 19:35 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-19 17:08 [RFC] net: remove busylock Eric Dumazet
2016-05-19 18:03 ` Alexander Duyck
2016-05-19 18:41   ` Rick Jones
2016-05-19 18:56   ` Eric Dumazet
2016-05-19 19:35     ` Eric Dumazet [this message]
2016-05-19 20:39       ` Alexander Duyck
2016-05-20  4:49         ` John Fastabend
2016-05-20  4:56           ` Eric Dumazet
2016-05-20  7:29   ` Jesper Dangaard Brouer
2016-05-20 13:11     ` Eric Dumazet
2016-05-20 13:47       ` Eric Dumazet
2016-05-20 14:16         ` Eric Dumazet
2016-05-20 17:49           ` Jesper Dangaard Brouer
2016-05-20 21:32             ` Eric Dumazet
2016-05-23  9:50               ` Jesper Dangaard Brouer
2016-05-23 21:24                 ` [PATCH net] net_sched: avoid too many hrtimer_start() calls Eric Dumazet
2016-05-24 21:49                   ` David Miller
2016-05-24 13:50             ` [RFC] net: remove busylock David Laight
2016-05-24 14:37               ` Eric Dumazet
2016-05-20 16:01       ` John Fastabend
2016-05-19 18:12 ` David Miller
2016-05-19 18:44   ` Eric Dumazet

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1463686523.18194.232.camel@edumazet-glaptop3.roam.corp.google.com \
    --to=eric.dumazet@gmail.com \
    --cc=aduyck@mirantis.com \
    --cc=alexander.duyck@gmail.com \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.