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DATE 2015-02-01

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MESSAGE
DATE 2015-02-17
FROM Ruben Safir
SUBJECT Subject: [LIU Comp Sci] OS Class Ctp 2 Dtrace
From owner-learn-outgoing-at-mrbrklyn.com Tue Feb 17 02:46:38 2015
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From: Ruben Safir
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Does anyone understand this? It is from Chapter to of the OS class
text. I'm very confused by the text here because it seems to be saying
that when probes are turned on they are rewritten and I don't know what
is rewritten. Can you rewrite a binary while its in memory? That would
be news to me.

Ruben


2.8.3
DTrace
DTrace is a facility that dynamically adds probes to a running system, both
in user processes and in the kernel. These probes can be queried via the D
programming language to determine an astonishing amount about the kernel,
the system state, and process activities. For example, Figure 2.20
follows an
application as it executes a system call (ioctl()) and shows the functional
calls within the kernel as they execute to perform the system call.
Lines ending
with “U” are executed in user mode, and lines ending in “K” in kernel mode.
88
Chapter 2 Operating-System Structures
Figure 2.19 The Windows task manager.
Debugging the interactions between user-level and kernel code is nearly
impossible without a toolset that understands both sets of code and can
instrument the interactions. For that toolset to be truly useful, it
must be able
to debug any area of a system, including areas that were not written with
debugging in mind, and do so without affecting system reliability. This tool
must also have a minimum performance impact—ideally it should have no
impact when not in use and a proportional impact during use. The DTrace tool
meets these requirements and provides a dynamic, safe, low-impact debugging
environment.
Until the DTrace framework and tools became available with Solaris 10,
kernel debugging was usually shrouded in mystery and accomplished via
happenstance and archaic code and tools. For example, CPUs have a breakpoint
feature that will halt execution and allow a debugger to examine the
state of the
system. Then execution can continue until the next breakpoint or
termination.
This method cannot be used in a multiuser operating-system kernel without
negatively affecting all of the users on the system. Profiling, which
periodically
samples the instruction pointer to determine which code is being
executed, can
show statistical trends but not individual activities. Code can be
included in
the kernel to emit specific data under specific circumstances, but that code
slows down the kernel and tends not to be included in the part of the kernel
where the specific problem being debugged is occurring.
2.8 Operating-System Debugging
89
# ./all.d ‘pgrep xclock‘ XEventsQueued
dtrace: script ’./all.d’ matched 52377 probes
CPU FUNCTION
0 –> XEventsQueued
U
0
–> _XEventsQueued
U
0
–> _X11TransBytesReadable
U
0
<– _X11TransBytesReadable
U
0
–> _X11TransSocketBytesReadable U
0
<– _X11TransSocketBytesreadable U
0
–> ioctl
U
0
–> ioctl
K
0
–> getf
K
0
–> set_active_fd
K
0
<– set_active_fd
K
0
<– getf
K
0
–> get_udatamodel
K
0
<– get_udatamodel
K
...
0
–> releasef
K
0
–> clear_active_fd
K
0
<– clear_active_fd
K
0
–> cv_broadcast
K
0
<– cv_broadcast
K
0
<– releasef
K
0
<– ioctl
K
0
<– ioctl
U
0
<– _XEventsQueued
U
0 <– XEventsQueued
U
Figure 2.20 Solaris 10 dtrace follows a system call within the kernel.
In contrast, DTrace runs on production systems—systems that are running
important or critical applications—and causes no harm to the system. It
slows activities while enabled, but after execution it resets the system
to its
pre-debugging state. It is also a broad and deep tool. It can broadly debug
everything happening in the system (both at the user and kernel levels and
between the user and kernel layers). It can also delve deep into code,
showing
individual CPU instructions or kernel subroutine activities.
DTrace is composed of a compiler, a framework, providers of probes
written within that framework, and consumers of those probes. DTrace
providers create probes. Kernel structures exist to keep track of all
probes that
the providers have created. The probes are stored in a hash-table data
structure
that is hashed by name and indexed according to unique probe identifiers.
When a probe is enabled, a bit of code in the area to be probed is rewritten
to call dtrace probe(probe identifier) and then continue with the code’s
original operation. Different providers create different kinds of
probes. For
example, a kernel system-call probe works differently from a user-process
probe, and that is different from an I/O probe.
DTrace features a compiler that generates a byte code that is run in the
kernel. This code is assured to be “safe” by the compiler. For example,
no loops
are allowed, and only specific kernel state modifications are allowed when
specifically requested. Only users with DTrace “privileges” (or “root”
users)
90
Chapter 2 Operating-System Structures
are allowed to use DTrace, as it can retrieve private kernel data (and
modify
data if requested). The generated code runs in the kernel and enables
probes.
It also enables consumers in user mode and enables communications between
the two.
A DTrace consumer is code that is interested in a probe and its results.
A consumer requests that the provider create one or more probes. When a
probe fires, it emits data that are managed by the kernel. Within the
kernel,
actions called enabling control blocks, or ECBs, are performed when probes
fire. One probe can cause multiple ECBs to execute if more than one consumer
is interested in that probe. Each ECB contains a predicate (“if
statement”) that
can filter out that ECB. Otherwise, the list of actions in the ECB is
executed. The
most common action is to capture some bit of data, such as a variable’s
value at
that point of the probe execution. By gathering such data, a complete
picture of
a user or kernel action can be built. Further, probes firing from both
user space
and the kernel can show how a user-level action caused kernel-level
reactions.
Such data are invaluable for performance monitoring and code optimization.
Once the probe consumer terminates, its ECBs are removed. If there are no
ECBs consuming a probe, the probe is removed. That involves rewriting the
code to remove the dtrace probe() call and put back the original code. Thus,
before a probe is created and after it is destroyed, the system is
exactly the
same, as if no probing occurred.
DTrace takes care to assure that probes do not use too much memory or
CPU capacity, which could harm the running system. The buffers used to hold
the probe results are monitored for exceeding default and maximum limits.
CPU time for probe execution is monitored as well. If limits are
exceeded, the
consumer is terminated, along with the offending probes. Buffers are
allocated
per CPU to avoid contention and data loss.
An example of D code and its output shows some of its utility. The following
program shows the DTrace code to enable scheduler probes and record the
amount of CPU time of each process running with user ID 101 while those
probes are enabled (that is, while the program runs):
sched:::on-cpu
uid == 101
{
self->ts = timestamp;
}
sched:::off-cpu
self->ts
{
-at-time[execname] = sum(timestamp - self->ts);
self->ts = 0;
}
The output of the program, showing the processes and how much time (in
nanoseconds) they spend running on the CPUs, is shown in Figure 2.21.
Because DTrace is part of the open-source OpenSolaris version of the Solaris
10 operating system, it has been added to other operating systems when those
2.9 Operating-System Generation
# dtrace -s sched.d
dtrace: script ’sched.d’ matched 6 probes
ˆC
gnome-settings-d
142354
gnome-vfs-daemon
158243
dsdm
189804
wnck-applet
200030
gnome-panel
277864
clock-applet
374916
mapping-daemon
385475
xscreensaver
514177
metacity
539281
Xorg
2579646
gnome-terminal
5007269
mixer applet2
7388447
java
10769137
Figure 2.21 Output of the D code.
91
systems do not have conflicting license agreements. For example, DTrace has
been added to Mac OS X and FreeBSD and will likely spread further due to its
unique capabilities. Other operating systems, especially the Linux
derivatives,
are adding kernel-tracing functionality as well. Still other operating
systems
are beginning to include performance and tracing tools fostered by
research at
various institutions, including the Paradyn project.

  1. 2015-02-01 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] DMA memory and CPU activity
  2. 2015-02-01 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] DMA memory and CPU activity
  3. 2015-02-01 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] DMA memory and CPU activity
  4. 2015-02-02 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] DMA memory and CPU activity
  5. 2015-02-02 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Operating System History
  6. 2015-02-02 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Operating System History
  7. 2015-02-02 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] study hall today
  8. 2015-02-02 Kamran <kamran.mirzayev-at-my.liu.edu> Re: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: [isoc-ny] Two NYC
  9. 2015-02-02 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] blackboard notice
  10. 2015-02-02 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Landing Jobs in the IT Field
  11. 2015-02-02 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Operating System History
  12. 2015-02-02 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Operating Systems Quiz
  13. 2015-02-02 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Re: Operating System History
  14. 2015-02-02 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Re: Operating System History
  15. 2015-02-02 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: [isoc-ny] Two NYC meetups Tuesday]
  16. 2015-02-03 Ruben <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: [isoc-ny] Two NYC
  17. 2015-02-04 Tony Genao <tony.genao-at-my.liu.edu> Re: [LIU Comp Sci] Compus Meeting
  18. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Compus Meeting
  19. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Compus Meeting
  20. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: [isoc-ny] Two NYC
  21. 2015-02-04 Tony Genao <tony.genao-at-my.liu.edu> Re: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: [isoc-ny] Two NYC
  22. 2015-02-04 Kamran <kamran.mirzayev-at-my.liu.edu> Re: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: [isoc-ny] Two NYC
  23. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: [isoc-ny] Two NYC
  24. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Operating System Design
  25. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Operating System Design
  26. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Operating System Design
  27. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Operating System Design
  28. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Operating System Design
  29. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Operating System Design
  30. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Operating System Design
  31. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Operating System Design
  32. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Re: Operating System Design
  33. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Re: Operating System Design
  34. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Re: Operating System Design
  35. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Re: Operating System Design
  36. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Re: Operating System Design
  37. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] (fwd) Re: Operating System Design
  38. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] algorithms pop tarts
  39. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] cgroups meeting
  40. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Compus Meeting
  41. 2015-02-04 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Essentail Database tools
  42. 2015-02-04 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] tony
  43. 2015-02-04 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] [info-at-fsf.org: Gorgeous animated video against DRM]
  44. 2015-02-05 Tony Genao <tony.genao-at-my.liu.edu> Re: [LIU Comp Sci] tony
  45. 2015-02-05 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] tony
  46. 2015-02-05 Tony Genao <tony.genao-at-my.liu.edu> Re: [LIU Comp Sci] tony
  47. 2015-02-05 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] SOC assignment
  48. 2015-02-05 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [NYLXS - HANGOUT] Very Good Jobs
  49. 2015-02-07 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: why not use naked delete ?]
  50. 2015-02-07 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: why not use naked delete ?]
  51. 2015-02-07 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: why not use naked delete ?]
  52. 2015-02-08 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] Double Stacks
  53. 2015-02-08 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] Double Stacks
  54. 2015-02-08 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: =?utf-8?Q?=5B?=
  55. 2015-02-09 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Invitation: cgroups and cgroups v2
  56. 2015-02-09 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] OS Design
  57. 2015-02-10 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Fwd: operating systems design
  58. 2015-02-10 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Student Computer Sciences Study Center
  59. 2015-02-10 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] [info-at-meetup.com: Invitation: NYLUG Open hacker hours]
  60. 2015-02-10 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] [info-at-meetup.com: Monday: Join 56 Rubyists at "Project Night"]
  61. 2015-02-11 Maneesh Kongara <maneeshkongara-at-gmail.com> Re: [LIU Comp Sci] Friday Morning Volunteer
  62. 2015-02-11 Ruben <ruben.safir-at-my.liu.edu> Re: [LIU Comp Sci] Friday Morning Volunteer
  63. 2015-02-11 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Re: [NYLXS - HANGOUT] Friday Morning Volunteer
  64. 2015-02-11 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] tony
  65. 2015-02-11 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Friday Morning Volunteer
  66. 2015-02-11 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Re: [NYLXS - HANGOUT] Friday Morning Volunteer
  67. 2015-02-11 Ruben <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: [NYLXS - HANGOUT] Friday Morning Volunteer
  68. 2015-02-11 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Towers of Hanio
  69. 2015-02-12 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] NEtworking Class
  70. 2015-02-12 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Re: Operating Systems (CS_643_001_BK_SPRG2015): Next Meeting Friday
  71. 2015-02-12 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: [NYLXS - HANGOUT] Friday Morning Volunteer
  72. 2015-02-12 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] [announce-at-lists.isoc-ny.org: =?utf-8?Q?=5B?=
  73. 2015-02-12 mrbrklyn-at-panix.com Subject: [LIU Comp Sci] [dmarti-at-zgp.org: [linux-elitists] No results found for "social
  74. 2015-02-13 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Re: Operating Systems (CS_643_001_BK_SPRG2015): Next Meeting
  75. 2015-02-15 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Friday Morning Volunteer
  76. 2015-02-15 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: Journal Article
  77. 2015-02-16 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Home Works
  78. 2015-02-17 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] OS Class Ctp 2 Dtrace
  79. 2015-02-18 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Hwk4 Allorithms
  80. 2015-02-18 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Recursive Allorithms
  81. 2015-02-19 From: "keisha.sylvester" <keisha.sylvester-at-my.liu.edu> RE: [LIU Comp Sci] Hwk4 Allorithms
  82. 2015-02-19 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Hwk4 Allorithms
  83. 2015-02-19 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Midterm Exams Samples
  84. 2015-02-20 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] a little C++ insite
  85. 2015-02-22 Ruben <ruben.safir-at-my.liu.edu> Re: [LIU Comp Sci] Binary tree Excersize
  86. 2015-02-22 Ruben <ruben.safir-at-my.liu.edu> Re: [LIU Comp Sci] Binary tree Excersize
  87. 2015-02-22 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Binary tree Excersize
  88. 2015-02-22 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Binary tree Excersize
  89. 2015-02-23 From: "keisha.sylvester" <keisha.sylvester-at-my.liu.edu> RE: Re: [LIU Comp Sci] Binary tree Excersize
  90. 2015-02-23 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Binary tree Excersize
  91. 2015-02-23 Keisha Sylvester <keisha.sylvester-at-my.liu.edu> Re: [LIU Comp Sci] Binary tree Excersize
  92. 2015-02-23 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Binary tree Excersize
  93. 2015-02-23 Ruben <ruben.safir-at-my.liu.edu> Re: [LIU Comp Sci] Binary tree Excersize
  94. 2015-02-23 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] scheduler resources
  95. 2015-02-23 Maneesh Kongara <maneeshkongara-at-gmail.com> Re: [LIU Comp Sci] Study Schedule for Tuesday
  96. 2015-02-23 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Study Schedule for Tuesday
  97. 2015-02-23 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Operating Systems Class on Friday
  98. 2015-02-23 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] scheduler resources
  99. 2015-02-23 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Study Schedule for Tuesday
  100. 2015-02-24 From: "keisha.sylvester" <keisha.sylvester-at-my.liu.edu> RE: Re: [LIU Comp Sci] Binary tree Excersize
  101. 2015-02-24 Ruben Safir <mrbrklyn-at-panix.com> Re: Re: [LIU Comp Sci] Binary tree Excersize
  102. 2015-02-24 From: "keisha.sylvester" <keisha.sylvester-at-my.liu.edu> RE: Re: [LIU Comp Sci] Study Schedule for Tuesday
  103. 2015-02-24 Maneesh Kongara <maneeshkongara-at-gmail.com> Re: [LIU Comp Sci] Binary tree Excersize
  104. 2015-02-24 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Binary tree Excersize
  105. 2015-02-24 Keisha Sylvester <keisha.sylvester-at-my.liu.edu> Re: [LIU Comp Sci] Study anyone??
  106. 2015-02-24 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Study anyone??
  107. 2015-02-25 Ruben <ruben.safir-at-my.liu.edu> Re: [LIU Comp Sci] Binary tree Excersize
  108. 2015-02-25 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Binary tree Excersize
  109. 2015-02-25 Keisha Sylvester <keisha.sylvester-at-my.liu.edu> Re: [LIU Comp Sci] Binary tree Excersize
  110. 2015-02-26 Ruben <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Binary tree Excersize
  111. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Campus
  112. 2015-02-26 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Fwd: [NYLXS - HANGOUT] Bios
  113. 2015-02-26 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Re: Fwd: [NYLXS - HANGOUT] Bios
  114. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  115. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  116. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  117. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  118. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  119. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  120. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  121. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  122. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  123. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  124. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  125. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Re: Role of functional dependencies in
  126. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [mrbrklyn-at-panix.com: (fwd) Role of functional dependencies in
  127. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [mrbrklyn-at-panix.com: (fwd) Re: [LIU Comp Sci] Need tutoring on
  128. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [mrbrklyn-at-panix.com: (fwd) Re: [LIU Comp Sci] Need tutoring on
  129. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [mrbrklyn-at-panix.com: (fwd) Re: [LIU Comp Sci] Need tutoring on
  130. 2015-02-26 Ruben Safir <mrbrklyn-at-panix.com> Subject: [mrbrklyn-at-panix.com: (fwd) Re: [LIU Comp Sci] Need tutoring on
  131. 2015-02-27 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] a hate this question
  132. 2015-02-27 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Allorithms Midterm
  133. 2015-02-27 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Read the FUCKING NOTES
  134. 2015-02-28 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Allgorithm Examination
  135. 2015-02-28 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] Linked List Test Question
  136. 2015-02-28 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: [NYLXS - HANGOUT] Read the FUCKING NOTES
  137. 2015-02-28 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [prmarino1-at-gmail.com: Re: [NYLXS - HANGOUT] Read the FUCKING NOTES

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