From: fche@redhat.com (Frank Ch. Eigler)
To: Mark Wielaard <mjw@redhat.com>
Cc: systemtap@sources.redhat.com
Subject: Re: Pass 4 (non-)optimization speedup
Date: Sun, 12 Jul 2009 01:51:00 -0000 [thread overview]
Message-ID: <y0mhbxiy8he.fsf@fche.csb> (raw)
In-Reply-To: <1247337122.2708.24.camel@hermans.wildebeest.org> (Mark Wielaard's message of "Sat, 11 Jul 2009 20:32:02 +0200")
Mark Wielaard <mjw@redhat.com> writes:
> To make pass 4 a bit more flexible I added -O[0123s] as arguments to
> stap (commit 5a5732). [...]
> The default is -O0 which makes pass 4 a lot faster, so I think this is a
> good default. [...]
No, it is unlikely to be a good default. Frankly, I'm surprised it
even compiles, since some kernel code is unbuildable without
optimization. Anyway, the code generated by systemtap is complex
enough that with optimization disabled, it is bound to run measurably
slower. Please test some nontrivial probes with -t before & after.
- FChE
next prev parent reply other threads:[~2009-07-12 1:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-11 18:32 Mark Wielaard
2009-07-12 1:51 ` Frank Ch. Eigler [this message]
2009-07-12 14:26 ` Mark Wielaard
2009-07-13 22:35 ` Mark Wielaard
2009-07-14 9:56 ` Mark Wielaard
2009-07-15 2:17 ` Josh Stone
2009-07-15 17:42 ` Frank Ch. Eigler
2009-07-15 2:17 ` Josh Stone
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=y0mhbxiy8he.fsf@fche.csb \
--to=fche@redhat.com \
--cc=mjw@redhat.com \
--cc=systemtap@sources.redhat.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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).