From: "H. Peter Anvin" <hpa@linux.intel.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Frederic Weisbecker <fweisbec@gmail.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vaibhav Nagarnaik <vnagarnaik@google.com>
Subject: Re: [RFC][PATCH] tracing/syscalls: Have ia32 compat syscalls show raw format
Date: Tue, 12 Feb 2013 11:54:01 -0800 [thread overview]
Message-ID: <511A9DD9.7090805@linux.intel.com> (raw)
In-Reply-To: <511A9A64.3040108@linux.intel.com>
On 02/12/2013 11:39 AM, H. Peter Anvin wrote:
> On 02/12/2013 10:42 AM, Steven Rostedt wrote:
>>
>> And currently the output is just plain broken. This isn't a hack. You
>> should have seen my first attempt. Now THAT was a hack! My first attempt
>> was extremely intrusive, and required a lot of arch changes. But then I
>> realized it was too much, and found that I could do the same thing
>> pretty much completely contained within just the tracing code itself.
>>
>> I know you feel that the syscall tracing is broken/hack/whatever. But it
>> exists as of today, and yes, there's lots of users out there depending
>> on it.
>>
>
> I am getting extremely frustrated with this cycle:
>
> 1. "We should have done <X> but we did <Y> because <X> was too
> hard/required arch changes/..."
> 2. "Well, <Y> is broken, but people rely on it. We should have done
> <X> but now it is too hard/breaks legacy/... so let's do <Z>..."
> 3. Lather, rinse, repeat.
>
> The whole system with trace metadata seems to be broken at the core,
> *exactly* because it intercepts at a different place than the one which
> has a well-defined ABI and every hack, kluge and patch which doesn't fix
> that fundamental design error will just make it worse and just kicks the
> can further down the road.
>
As to why I care: I care about the number of ways we present ABIs to
userspace. The current tracing code takes the kernel internal
implementation and makes it an ABI -- that ties the hands of kernel
developers forever, because we can't know what we break if we redesign it.
-hpa
next prev parent reply other threads:[~2013-02-12 19:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-12 18:01 [RFC][PATCH] tracing/syscalls: Have ia32 compat syscalls show raw format Steven Rostedt
2013-02-12 18:11 ` H. Peter Anvin
2013-02-12 18:42 ` Steven Rostedt
2013-02-12 18:51 ` Steven Rostedt
2013-02-12 19:39 ` H. Peter Anvin
2013-02-12 19:54 ` H. Peter Anvin [this message]
2013-02-12 21:18 ` [RFC][PATCH v2] tracing/syscalls: Allow archs to ignore tracing compat syscalls Steven Rostedt
2013-02-12 21:33 ` H. Peter Anvin
2013-02-12 21:42 ` Steven Rostedt
2013-02-12 22:34 ` H. Peter Anvin
2013-02-20 13:55 ` [tip:perf/urgent] " tip-bot for Steven Rostedt
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