From: Andi Kleen <ak@muc.de>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org, peterc@gelato.unsw.edu.au
Subject: Re: Microstate Accounting for 2.6.11
Date: Fri, 11 Mar 2005 08:14:25 +0100 [thread overview]
Message-ID: <m1acpazmb2.fsf@muc.de> (raw)
In-Reply-To: <20050310200808.306caf98.akpm@osdl.org> (Andrew Morton's message of "Thu, 10 Mar 2005 20:08:08 -0800")
Andrew Morton <akpm@osdl.org> writes:
> Why does the kernel need this feature?
>
> Have you any numbers on the overhead?
It does RDTSC and lots of complicated stuff twice for each system call.
On P4 this will be extremly slow (> 1000cycles combined)
It is pretty unlikely that whatever it does justifies this extreme
overhead in a critical fast path.
-Andi
next prev parent reply other threads:[~2005-03-11 7:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-11 3:42 Microstate Accounting for 2.6.11 Peter Chubb
2005-03-11 4:08 ` Andrew Morton
2005-03-11 5:01 ` Peter Chubb
2005-03-11 7:14 ` Andi Kleen [this message]
2005-03-11 8:39 ` Peter Chubb
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=m1acpazmb2.fsf@muc.de \
--to=ak@muc.de \
--cc=akpm@osdl.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterc@gelato.unsw.edu.au \
/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.