From: "Frank Ch. Eigler" <fche@redhat.com>
To: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: Christoph Hellwig <hch@lst.de>, systemtap@sources.redhat.com
Subject: Re: [Ksummit-2008-discuss] DTrace
Date: Sun, 06 Jul 2008 21:46:00 -0000 [thread overview]
Message-ID: <20080706213920.GA1936@redhat.com> (raw)
In-Reply-To: <20080706182307.GA29895@2ka.mipt.ru>
Hi -
On Sun, Jul 06, 2008 at 10:23:08PM +0400, Evgeniy Polyakov wrote:
> > Yes, well, it turns out that the number of systemtap-specific kernel
> > interfaces we have requested is ... precisely ... zero.
>
> Well, in the mail you replied to there was objection to add new
> interfaces.
That just illustrates the imperfect information floating around.
> > We have on occasion asked that some established module interfaces
> > simply not be *unexported*, but almost all of those requests have been
> > turned down, requiring us to kludge. [...]
>
> Unexporting some things allows to change them in order to fix some bugs,
> create better abstraction, introduce new feature... Having all calls
> forever does not provide any gain to the kernel, instead project can be
> pushed into the kernel, so anyone would win.
OK, so you think systemtap should go into the kernel ...
> > Think about how a non-intrusive system-wide probing must work,
> > [...] It seems only kernel-side code can do all of that. Do you
> > have a better suggestion?
> Hmmm... Utrace suddenly stopped to work?
(I assume you know that utrace is a kernel-side API. You may realize
is that we are using it (via another layered module uprobes) to place
probes into user-space programs.)
> Even ptrace will work in described cases, if requested data is
> accessible from userspace. [...]
... but now systemtap stay out to userspace? I don't understand.
> And is it really much simpler to use dtrace scripts [...] for that?
Simpler than what? A userspace debugger that messes with thread state?
> (btw, does systemtap has the same complexity of script writing?
If you point out an example of what you consider a complex dtrace
script, I can try to answer that.
- FChE
next prev parent reply other threads:[~2008-07-06 21:46 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20080627150424.GB14894@parisc-linux.org>
[not found] ` <1214580213.3394.40.camel@localhost.localdomain>
[not found] ` <20080627155018.GC14894@parisc-linux.org>
[not found] ` <1214583502.7698.15.camel@weaponx>
[not found] ` <20080627163056.GB1416@lst.de>
[not found] ` <20080628072605.GA505@in.ibm.com>
[not found] ` <20080629084002.GA24131@lst.de>
[not found] ` <20080630051034.GA4970@in.ibm.com>
[not found] ` <20080630112913.GA18817@lst.de>
2008-06-30 19:27 ` Frank Ch. Eigler
2008-07-01 1:21 ` Jim Keniston
[not found] ` <20080706123414.GA9265@lst.de>
2008-07-06 15:47 ` Frank Ch. Eigler
2008-07-06 16:36 ` Evgeniy Polyakov
2008-07-06 18:05 ` Frank Ch. Eigler
2008-07-06 18:24 ` Evgeniy Polyakov
2008-07-06 21:46 ` Frank Ch. Eigler [this message]
2008-07-06 22:47 ` Karen Shaeffer
2008-07-06 23:15 ` Frank Ch. Eigler
2008-07-07 5:59 ` Evgeniy Polyakov
2008-07-07 11:19 ` Frank Ch. Eigler
[not found] ` <20080627182754.GB7549@mit.edu>
[not found] ` <1214597135.3394.82.camel@localhost.localdomain>
[not found] ` <aday74qlh08.fsf@cisco.com>
[not found] ` <4865B111.2040307@redhat.com>
[not found] ` <adavdzujh2u.fsf@cisco.com>
[not found] ` <20080704200055.GA11232@synapse.neuralscape.com>
[not found] ` <20080704224424.GA12454@synapse.neuralscape.com>
[not found] ` <1215273663.3439.34.camel@localhost.localdomain>
2008-07-06 23:33 ` Frank Ch. Eigler
2008-07-07 14:35 ` James Bottomley
2008-07-07 15:02 ` James Bottomley
2008-06-30 13:57 DTrace Frank Ch. Eigler
2008-06-30 19:00 ` [Ksummit-2008-discuss] DTrace Grant Grundler
2008-06-30 19:40 ` Theodore Tso
2008-06-30 20:00 ` Frank Ch. Eigler
2008-06-30 20:19 ` Theodore Tso
2008-06-30 21:12 ` Arnaldo Carvalho de Melo
2008-06-30 23:02 ` David Miller
2008-06-30 21:13 ` James Bottomley
2008-06-30 22:10 ` Frank Ch. Eigler
2008-07-01 2:42 ` Theodore Tso
2008-07-01 7:08 ` Roland McGrath
2008-07-01 10:15 ` Theodore Tso
2008-07-01 11:04 ` Sam Ravnborg
2008-07-01 12:13 ` Theodore Tso
2008-07-02 20:27 ` Sam Ravnborg
2008-07-01 20:06 ` Roland McGrath
2008-07-01 23:13 ` Theodore Tso
2008-07-02 2:23 ` Frank Ch. Eigler
2008-07-02 19:27 ` Frank Ch. Eigler
2008-07-02 20:08 ` Joel Becker
2008-07-02 20:17 ` J. Bruce Fields
2008-07-02 20:41 ` Frank Ch. Eigler
2008-07-02 21:19 ` H. Peter Anvin
2008-07-02 21:30 ` Theodore Tso
2008-07-02 21:46 ` J. Bruce Fields
2008-07-05 9:46 ` Peter Zijlstra
2008-07-05 10:07 ` Christoph Hellwig
2008-07-05 12:12 ` Frank Ch. Eigler
2008-07-05 18:08 ` Christoph Hellwig
2008-07-05 13:50 ` James Bottomley
2008-07-05 18:08 ` Christoph Hellwig
2008-07-05 18:05 ` K.Prasad
2008-07-07 14:36 ` Christoph Hellwig
2008-07-07 17:44 ` K.Prasad
2008-07-05 12:34 ` Theodore Tso
2008-07-01 5:29 ` Ananth N Mavinakayanahalli
2008-06-30 19:59 ` James Bottomley
2008-06-30 23:52 ` Masami Hiramatsu
2008-07-08 23:32 ` Eric W. Biederman
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