On Thu, 2010-01-28 at 09:55 +0100, Ingo Molnar wrote:
* Jim Keniston jkeni...@us.ibm.com wrote:
On Wed, 2010-01-27 at 09:54 +0100, Ingo Molnar wrote:
...
Yes, emulating push %ebp would buy us a lot of coverage for a lot of apps
on x86 (but see below**). [...]
...
[...] Even
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
On Fri, 2010-01-22 at 19:06 +0100, Peter Zijlstra wrote:
On Fri, 2010-01-22 at 12:32 +0530, Srikar Dronamraju wrote:
2. XOL vma vs Emulation vs Single Stepping Inline vs using Protection
Rings.
XOL VMA is an additional process address vma. This is
opposition to add an
On Tue, 2010-01-19 at 10:07 +0200, Avi Kivity wrote:
On 01/19/2010 12:15 AM, Jim Keniston wrote:
I don't like the idea but if the performance benefits are real (are
they?),
Based on what seems to be the closest thing to an apples-to-apples
comparison -- counting the number
On Mon, 2010-01-18 at 10:58 -0500, Masami Hiramatsu wrote:
Jim Keniston wrote:
Not really. For #3 (boosting), you need to know everything for #2,
plus be able to compute the length of each instruction -- which we can
now do for x86. To emulate an instruction (#4), you need
On Mon, 2010-01-18 at 14:34 +0100, Mark Wielaard wrote:
On Mon, 2010-01-18 at 14:53 +0200, Avi Kivity wrote:
On 01/18/2010 02:51 PM, Pekka Enberg wrote:
And how many probes do we expected to be live at the same time in
real-world scenarios? I guess Avi's one million is more than
On Fri, 2010-01-15 at 10:07 +0100, Peter Zijlstra wrote:
On Thu, 2010-01-14 at 14:43 -0800, Jim Keniston wrote:
Yeah, there's not a lot of context there. I hope it will make more
sense if you read section 1.1 of Documentation/uprobes.txt (patch #6).
Or look at get_insn_slot
On Fri, 2010-01-15 at 10:02 +0100, Peter Zijlstra wrote:
On Thu, 2010-01-14 at 11:46 -0800, Jim Keniston wrote:
+Instruction copies to be single-stepped are stored in a per-process
+single-step out of line (XOL) area, which is a little VM area
+created by Uprobes in each probed
On Fri, 2010-01-15 at 12:18 +0100, Peter Zijlstra wrote:
On Fri, 2010-01-15 at 12:12 +0100, Peter Zijlstra wrote:
...
Adding the probe uses the fact that (most) executable mappings are
MAP_PRIVATE and CoWs a private copy of the page with the modified ins,
right?
We've just used
On Fri, 2010-01-15 at 19:50 +0530, Srikar Dronamraju wrote:
Furthermore it requires stopping and resuming tasks and nonsense like
that, that's unwanted in many cases, just run stuff from the trap site
and you're done.
I don't know what you mean exactly. A trap already
On Fri, 2010-01-15 at 12:12 +0100, Peter Zijlstra wrote:
...
Adding the probe uses the fact that (most) executable mappings are
MAP_PRIVATE and CoWs a private copy of the page with the modified ins,
right?
What does it do for MAP_SHARED|MAP_EXECUTABLE sections -- simply fail to
add the
On Thu, 2010-01-14 at 12:08 +0100, Peter Zijlstra wrote:
On Mon, 2010-01-11 at 17:55 +0530, Srikar Dronamraju wrote:
User Space Breakpoint Assistance Layer (UBP)
User space breakpointing Infrastructure provides kernel subsystems
with architecture independent interface to establish
On Thu, 2010-01-14 at 12:08 +0100, Peter Zijlstra wrote:
On Mon, 2010-01-11 at 17:55 +0530, Srikar Dronamraju wrote:
Execution out of line (XOL)
Slot allocation mechanism for Execution Out of Line strategy in User
space breakpointing Inftrastructure. (XOL)
This patch provides slot
On Thu, 2010-01-14 at 12:09 +0100, Peter Zijlstra wrote:
On Mon, 2010-01-11 at 17:55 +0530, Srikar Dronamraju wrote:
Uprobes Infrastructure enables user to dynamically establish
probepoints in user applications and collect information by executing
a handler functions when the
On Tue, 2010-01-12 at 13:44 +0530, Ananth N Mavinakayanahalli wrote:
On Tue, Jan 12, 2010 at 06:36:00AM +0100, Frederic Weisbecker wrote:
...
So, as stated before, uprobe seems to handle too much standalone
policies such as freeing on exec, always inherit on clone and never
on fork. Such
On Mon, 2009-08-10 at 12:42 -0400, Frank Ch. Eigler wrote:
Hi -
On Mon, Aug 03, 2009 at 11:10:00AM -0700, Jim Keniston wrote:
[...]
So as per my analysis, gdb_utrace_report_signal was called, followed by
uprobe_report_signal. Since gdb_utrace_report_signal requested for
UTRACE_STOP
On Thu, 2009-07-30 at 15:26 +0530, Ananth N Mavinakayanahalli wrote:
+static u32 core_clone(enum utrace_resume_action action,
...
+ /*
+ * -EINPROGRESS = thread on the way to quiesce
+ * -EALREADY = we may be racing with attach_utrace_engines
+
tucked into the SystemTap
runtime (runtime/uprobes[2]) since October 2007, but for various reasons
(LONG story) it hasn't debuted on LKML yet.
The uprobes API is documented in the SystemTap source:
runtime/uprobes/uprobes.txt.
Jim Keniston
As promised on yesterday's SystemTap call, here's inat.c. It consists
of a couple of tables that capture more information about the x86
instruction sets. For example, you could use this code to determine
whether an opcode/instruction is invalid, privileged, a floating-point
op, or in some other
On Tue, 2009-03-31 at 10:09 -0400, Frank Ch. Eigler wrote:
ananth wrote:
Uprobes is implemented only for architectures that have utrace support
(x86-32, x86_64, powerpc, s390, but not IA64). [...]
(HAVE_ARCH_TRACEHOOK is on for ia64, sparc, sh also, so utrace per se
should work there.)
Quoting Masami Hiramatsu mhira...@redhat.com:
Hi Jim and Sriker,
Here, I almost rewrote my patch.
Changelog:
- rewrite decoding logic based on Intel' manual.
- supoort insn_get_sib(),insn_get_displacement()
and insn_get_immediate() too.
- support 3 bytes opcode and 64bit immediate.
-
On Fri, 2009-02-27 at 16:20 -0500, Masami Hiramatsu wrote:
...
Here are a patch against your code and an example code for
instruction length decoder.
Curiously, KVM's instruction decoder does not completely
cover all instructions(especially, Jcc/test...).
I had to refer Intel manuals.
On Wed, 2008-12-17 at 01:21 -0800, Roland McGrath wrote:
The current implementation is that if I create a new engine in response
to an exec (when called from some other engine's report_exec callback),
and set that engine's flags to be notified of execs, the new engine gets
notified of the
In utrace code fetched today, cscope reports 16 lines with references to
obsolete UTRACE_ACTION_something symbols. They're all in comments or
#if 0 code, so they don't break the build, but those comments aren't
very helpful in their current state.
Jim
doing this in userspace is for sure a better idea.
Can you elaborate upon this more complex scenario?
- FChE
Jim Keniston
instruction tracing.
Jim Keniston
IBM Linux Technology Center
Forwarded Message
From: Roland McGrath [EMAIL PROTECTED]
To: Jim Keniston [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED], Maneesh Soni [EMAIL PROTECTED], Frank Eigler
[EMAIL PROTECTED]
Subject: Re: utrace refactoring...
Date: Sun, 11
26 matches
Mail list logo
