On Wed, 2010-01-27 at 07:53 +0100, Peter Zijlstra wrote:
On Fri, 2010-01-22 at 12:54 +0530, Ananth N Mavinakayanahalli wrote:
On Fri, Jan 22, 2010 at 12:32:32PM +0530, Srikar Dronamraju wrote:
Here is a summary of the Comments and actions that need to be taken for
the current uprobes
On 01/27/2010 10:24 AM, Ingo Molnar wrote:
Not to mention that that process could wreck the trace data rendering it
utterly unreliable.
It could, but it also might not. Are we going to deny high performance
tracing to users just because it doesn't work in all cases?
Tracing
* Peter Zijlstra pet...@infradead.org wrote:
On Tue, 2010-01-26 at 15:37 -0800, Linus Torvalds wrote:
On Tue, 26 Jan 2010, Tom Tromey wrote:
In non-stop mode (where you can stop one thread but leave the others
running), gdb wants to have the breakpoints always inserted. So,
* Avi Kivity a...@redhat.com wrote:
On 01/27/2010 10:24 AM, Ingo Molnar wrote:
Not to mention that that process could wreck the trace data rendering it
utterly unreliable.
It could, but it also might not. Are we going to deny high performance
tracing to users just because it doesn't
* Avi Kivity a...@redhat.com wrote:
If so then you ignore the obvious solution to _that_ problem: dont use
INT3 at all, but rebuild (or re-JIT) your program with explicit callbacks.
It's _MUCH_ faster than _any_ breakpoint based solution - literally just
the cost of a function call
On Wed, 27 Jan 2010, Peter Zijlstra wrote:
Right, so you're going to love uprobes, which does exactly that. The
current proposal is overwriting the target instruction with an INT3 and
injecting an extra vma into the target process's address space
containing the original instruction(s) and
On Wed, 2010-01-27 at 02:43 -0800, Linus Torvalds wrote:
On Wed, 27 Jan 2010, Peter Zijlstra wrote:
Right, so you're going to love uprobes, which does exactly that. The
current proposal is overwriting the target instruction with an INT3 and
injecting an extra vma into the target
On Wed, 2010-01-27 at 11:55 +0100, Peter Zijlstra wrote:
Right, so there's two aspects:
1) concurrency when inserting the probe
2) concurrency when hitting the probe
1) used to be dealt with by using utrace to stop all threads in the
process and then writing the instruction. I suggested
On Wed, Jan 27, 2010 at 11:55:16AM +0100, Peter Zijlstra wrote:
On Wed, 2010-01-27 at 02:43 -0800, Linus Torvalds wrote:
On Wed, 27 Jan 2010, Peter Zijlstra wrote:
Right, so you're going to love uprobes, which does exactly that. The
current proposal is overwriting the target
On Wed, 27 Jan 2010, Peter Zijlstra wrote:
Right, so there's two aspects:
1) concurrency when inserting the probe
That's the one I worried about. Stopping all threads will fix it,
obviously at a disastrous performance cost, but what do I care? As noted,
there are ways to do it safely
On Wed, 2010-01-27 at 16:35 +0530, Ananth N Mavinakayanahalli wrote:
Probing RIP-relative instructions work just fine; there are fixups that
take care of it.
Ah my bad then, it was my understanding you simply bailed on those.
Just for my information, how large are the replacement sequences?
On Wed, Jan 27, 2010 at 12:08:31PM +0100, Peter Zijlstra wrote:
On Wed, 2010-01-27 at 16:35 +0530, Ananth N Mavinakayanahalli wrote:
Probing RIP-relative instructions work just fine; there are fixups that
take care of it.
Ah my bad then, it was my understanding you simply bailed on those.
[ Added Arjan ]
On Wed, 2010-01-27 at 02:43 -0800, Linus Torvalds wrote:
On Wed, 27 Jan 2010, Peter Zijlstra wrote:
Right, so you're going to love uprobes, which does exactly that. The
current proposal is overwriting the target instruction with an INT3 and
injecting an extra vma into
On 01/27/2010 02:43 AM, Linus Torvalds wrote:
On Wed, 27 Jan 2010, Peter Zijlstra wrote:
Right, so you're going to love uprobes, which does exactly that. The
current proposal is overwriting the target instruction with an INT3 and
injecting an extra vma into the target process's address
On Wed, 2010-01-27 at 09:54 +0100, Ingo Molnar wrote:
...
I think the best solution for user probes (by far) is to use a simplified
in-kernel instruction emulator for the few common probes instruction.
(Kprobes
already partially decodes x86 instructions to make it safe to apply
KONYANIN EN BUYUK FiRMA REHBERiNE KAYIT OLUN www.buyukkonyafirmarehberi.com
16 matches
Mail list logo
