Messages in this thread | | | Date | Tue, 12 Feb 2013 11:54:01 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [RFC][PATCH] tracing/syscalls: Have ia32 compat syscalls show raw format |
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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
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