mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Namhyung Kim <namhyung@kernel.org>
To: Eric Dumazet <erdnetdev@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	David Miller <davem@davemloft.net>,
	netdev <netdev@vger.kernel.org>,
	"linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Tom Herbert <therbert@google.com>
Subject: Re: [PATCH net-next] softirq: reduce latencies
Date: Fri, 04 Jan 2013 14:16:53 +0900	[thread overview]
Message-ID: <87r4m1r0hm.fsf@sejong.aot.lge.com> (raw)
In-Reply-To: <1357252875.21409.26390.camel@edumazet-glaptop> (Eric Dumazet's message of "Thu, 03 Jan 2013 14:41:15 -0800")

Hi,

On Thu, 03 Jan 2013 14:41:15 -0800, Eric Dumazet wrote:
> On Thu, 2013-01-03 at 12:46 -0800, Andrew Morton wrote:
>> Can this change cause worsened latencies in some situations?  Say there
>> are a large number of short-running actions queued.  Presently we'll
>> dispatch ten of them and return.  With this change we'll dispatch many
>> more of them - however many consume 2ms.  So worst-case latency
>> increases from "10 * not-much" to "2 ms".
>
> I tried to reproduce such workload but couldnt. 2 ms (or more exactly 1
> to 2 ms given the jiffies/HZ granularity) is about the time needed to
> process 1000 frames on current hardware.

Probably a silly question:

Why not using ktime rather than jiffies for this?

Thanks,
Namhyung

  reply	other threads:[~2013-01-04  5:16 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-03 12:28 Eric Dumazet
2013-01-03 20:46 ` Andrew Morton
2013-01-03 22:41   ` Eric Dumazet
2013-01-04  5:16     ` Namhyung Kim [this message]
2013-01-04  6:53       ` Eric Dumazet
     [not found]     ` <787701357283699@web24e.yandex.ru>
2013-01-04  7:46       ` Eric Dumazet
2013-01-03 22:08 ` Ben Hutchings
2013-01-03 22:40   ` Eric Dumazet
2013-01-04  7:49     ` [PATCH v2 " Eric Dumazet
2013-01-04  8:15       ` Joe Perches
2013-01-04  8:23         ` Eric Dumazet
2013-01-04  9:12           ` Joe Perches
2013-01-04 17:00             ` Eric Dumazet
2013-01-04 21:15               ` [PATCH] jiffies conversions: Use compile time constants when possible Joe Perches
2013-01-04 21:49       ` [PATCH v2 net-next] softirq: reduce latencies David Miller
2013-01-03 13:12 [PATCH " Sedat Dilek
2013-01-03 13:31 ` Eric Dumazet
2013-01-03 19:41   ` Rick Jones
2013-01-04  4:41     ` Eric Dumazet
2013-01-04  5:31       ` Sedat Dilek
2013-01-04  6:54         ` Eric Dumazet
2013-01-04 11:57       ` Sedat Dilek

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=87r4m1r0hm.fsf@sejong.aot.lge.com \
    --to=namhyung@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=davem@davemloft.net \
    --cc=erdnetdev@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=therbert@google.com \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome