From: "Ted Ts'o" <tytso@mit.edu>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ingo Molnar <mingo@elte.hu>, Greg KH <greg@kroah.com>,
devel@driverdev.osuosl.org, Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, lttng-dev@lists.lttng.org,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: Perf ABI (was: Re: [lttng-dev] [PATCH 09/11] sched: export task_prio to GPL modules)
Date: Fri, 23 Dec 2011 12:21:55 -0500 [thread overview]
Message-ID: <20111223172155.GA14117@thunk.org> (raw)
In-Reply-To: <20111223164629.GA30474@Krystal>
On Fri, Dec 23, 2011 at 11:46:29AM -0500, Mathieu Desnoyers wrote:
> - It's doing so without even needing it: Perf is using an ABI versioning
> scheme designed for filesystems, when it is not in fact driven by the
> same constraints.
Well, there are *some* constraints. I've been assured that despite
the fact that the perf client is in the kernel sources (something
which I still think is a bad idea, since it's leading to other bad
choices like kvm-tool wanting to be bundled with kernel sources), that
it is *not* a license to jerk the format around wildly --- that people
will have installed userspace binaries that shouldn't randomly break
they boot a new kernel.
So I'm *glad* that Perf is using an ABI versioning scheme that accepts
the same restraints as file systems. It means we don't randomly break
userspace tools.
So Mathieu, if you think it is the current standards of backwards
compatibility are too rigid, what level of tool breakage do you think
is acceptable? It's not just about the backwards compatibility of the
trace files, it's also about compatibility of userspace utilities.
For example, systemtap, where you had to recompile from source at
each kernel revision, and pray it would still build goes too far in
the other direction, wouldn't you agree? What is the correct level of
kernel developer annoyance you think is appropriate to inflict on
ourselves?
Regards,
- Ted
next prev parent reply other threads:[~2011-12-23 17:22 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1322775683-8741-1-git-send-email-mathieu.desnoyers@efficios.com>
2011-12-01 21:41 ` [PATCH 01/11] mm: export vmalloc_sync_all symbol to GPL modules Mathieu Desnoyers
2011-12-01 21:41 ` Mathieu Desnoyers
2011-12-01 21:57 ` Christoph Hellwig
2011-12-01 21:57 ` Christoph Hellwig
2011-12-01 22:13 ` Greg KH
2011-12-01 22:13 ` Greg KH
2011-12-01 22:19 ` Mathieu Desnoyers
2011-12-01 22:19 ` Mathieu Desnoyers
2011-12-01 22:41 ` Greg KH
2011-12-01 22:41 ` Greg KH
2011-12-01 22:28 ` Christoph Hellwig
2011-12-01 22:28 ` Christoph Hellwig
2011-12-01 23:00 ` Greg KH
2011-12-01 23:00 ` Greg KH
2011-12-01 21:57 ` Christoph Hellwig
2011-12-01 21:57 ` Christoph Hellwig
2011-12-01 21:57 ` Christoph Hellwig
2011-12-01 21:41 ` [PATCH 03/11] fs/splice: export splice_to_pipe " Mathieu Desnoyers
2011-12-02 7:19 ` Jens Axboe
2011-12-02 12:32 ` Mathieu Desnoyers
2011-12-01 21:41 ` [PATCH 09/11] sched: export task_prio " Mathieu Desnoyers
2011-12-01 21:56 ` Peter Zijlstra
2011-12-01 22:04 ` Mathieu Desnoyers
2011-12-01 22:10 ` Peter Zijlstra
2011-12-01 22:15 ` Mathieu Desnoyers
2011-12-01 22:36 ` Mathieu Desnoyers
2011-12-01 23:05 ` Peter Zijlstra
2011-12-02 13:51 ` Mathieu Desnoyers
2011-12-01 23:06 ` Peter Zijlstra
2011-12-01 23:18 ` Greg KH
2011-12-01 23:47 ` Mathieu Desnoyers
2011-12-01 22:14 ` Greg KH
2011-12-01 22:20 ` Mathieu Desnoyers
2011-12-01 23:07 ` Peter Zijlstra
2011-12-01 23:17 ` Greg KH
2011-12-05 14:17 ` Ingo Molnar
2011-12-06 21:44 ` Greg KH
2011-12-08 5:23 ` Ingo Molnar
2011-12-08 23:27 ` Greg KH
2011-12-19 10:49 ` Ingo Molnar
2011-12-19 15:30 ` [lttng-dev] " Mathieu Desnoyers
2011-12-20 11:08 ` Ingo Molnar
2011-12-20 21:46 ` Frank Rowand
2011-12-23 10:51 ` Ingo Molnar
2011-12-21 18:47 ` Aaron Spear
2011-12-21 18:58 ` Christoph Hellwig
2011-12-23 16:46 ` Perf ABI (was: Re: [lttng-dev] [PATCH 09/11] sched: export task_prio to GPL modules) Mathieu Desnoyers
2011-12-23 17:21 ` Ted Ts'o [this message]
2011-12-23 18:16 ` Mathieu Desnoyers
2011-12-25 17:46 ` Ted Ts'o
2012-01-12 14:09 ` Mathieu Desnoyers
2012-01-12 14:54 ` Steven Rostedt
2012-01-12 15:39 ` [lttng-dev] Perf ABI (was: " Mathieu Desnoyers
2012-01-12 15:53 ` Steven Rostedt
2012-01-12 15:59 ` Steven Rostedt
2012-01-12 16:27 ` Mathieu Desnoyers
2012-01-12 16:34 ` Steven Rostedt
2012-01-12 20:00 ` Greg KH
2012-01-16 8:55 ` Ingo Molnar
2011-12-07 22:57 ` [PATCH 09/11] sched: export task_prio to GPL modules Mathieu Desnoyers
2011-12-08 5:40 ` Ingo Molnar
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=20111223172155.GA14117@thunk.org \
--to=tytso@mit.edu \
--cc=acme@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=devel@driverdev.osuosl.org \
--cc=greg@kroah.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lttng-dev@lists.lttng.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/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.