From: Stephen Hemminger <stephen@networkplumber.org>
To: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Cc: "bloat@lists.bufferbloat.net" <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] Hardware upticks
Date: Tue, 5 Jan 2016 17:22:11 -0800 [thread overview]
Message-ID: <20160105172211.52c67535@xeon-e3> (raw)
In-Reply-To: <20160106005537.GA20844@sesse.net>
On Wed, 6 Jan 2016 01:55:37 +0100
"Steinar H. Gunderson" <sgunderson@bigfoot.com> wrote:
> On Tue, Jan 05, 2016 at 04:53:14PM -0800, Stephen Hemminger wrote:
> >> Also, I've never ever seen the actual context switch turn up high in a perf
> >> profile. Is this because of some sampling artifact?
> > Yes, especially with Intel processors getting more and more SSE/floating point
> > registers.
>
> But those are not saved on context switch to the kernel, no? (Thus the rule
> of no floating-point in the kernel.) Only if you switch between userspace
> processes
Right that just punts the work to the kernel when it context switches
to next process.
next prev parent reply other threads:[~2016-01-06 1:22 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-05 6:37 Jonathan Morton
2016-01-05 17:42 ` Aaron Wood
2016-01-05 18:27 ` Jonathan Morton
2016-01-05 18:57 ` Dave Täht
2016-01-05 19:29 ` Steinar H. Gunderson
2016-01-05 19:37 ` Dave Täht
2016-01-05 20:13 ` David Collier-Brown
2016-01-05 20:27 ` Stephen Hemminger
2016-01-05 21:10 ` Jonathan Morton
2016-01-05 23:20 ` Steinar H. Gunderson
2016-01-05 23:17 ` Steinar H. Gunderson
2016-01-05 21:36 ` Benjamin Cronce
2016-01-06 0:01 ` Steinar H. Gunderson
2016-01-06 0:06 ` Stephen Hemminger
2016-01-06 0:22 ` Steinar H. Gunderson
2016-01-06 0:53 ` Stephen Hemminger
2016-01-06 0:55 ` Steinar H. Gunderson
2016-01-06 1:22 ` Stephen Hemminger [this message]
2016-01-06 6:18 ` Jonathan Morton
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