►
From YouTube: Getting Up to Speed on OpenMP 4.0 (Part 2)
Description
(2/5) Ruud van der Pas, Distinguished Engineer in the Architecture and Performance Group, SPARC Microelectronics, Oracle, also a co-author of the book "Using OpenMP" (published by MIT press), presented this tutorial on OpenMP 4.0 for NERSC users.
A
I
said
photo
roseburg,
that's
what
we
we
all
live
goodbye
and
use.
Today.
Just
last
month
the
port
of
one
drive
specifications
were
published
and
and
you're
welcome,
to
read
them
and
content
feedback
on
it.
I
will
cover
photo.
I
won't
go
over
one,
although
that
one
scene
has
been
officially
certified
and
that's
the
news.
A
So
one
of
the
nice
things
is
the
wide
support
both
by
the
industry,
as
well
as
the
research
and
academic
community.
So
pretty
much.
Everybody
in
the
industry
supports
OpenMP
and
that's
really
group
good
things
beggining.
It
also
gives
very
wise
feedback
input
and
it
definitely
increases
use
its
affordability.
So
that's
a
good
thing.
You
can
get
this
list
from
the
openmp
torg
website.
A
Depending
on
your
language,
your
algorithm,
the
way
you
type
it
all
in
a
compiler
can
either
do
magic
on
a
fine
much.
It
tends
to
be
that
fortune,
especially
the
older
style
for
trend,
is
easier
for
compiler
to
analyze
than
C
C++,
the
higher
the
level
of
extraction
the
harder
it
is
for
a
compiler
in
general
to
find
intelligent.
But
it's
worth
a
try,
Oh
God
for
your
compiler.
What
option
there
is
to
do
that?
A
I,
don't
know,
but
one
of
the
compiler
is,
doesn't
find
the
parallelism
or
find
paladin
at
a
level
that
you
say
that
is
not
good
enough.
It
just
paralyzed
some
initialization,
loops
and
I
said
I
need
more.
So
that's
a
reason
to
until
you
open
it
and,
of
course,
if
you're
not
using
any
automatically
biological
father
at
all
or
you
don't
like
to
go
there
then
OpenAPI
is
the
natural
choice.
A
Be
aware
that
many
compilers
have
options
to
help
you
to
give
warnings,
and
you
know
openmp
is
a
very
harsh
model
in
the
sense
that
you
tell
it
to
paralyze
something
integral
do
so
if
you
answer,
but
what
have
you
made
a
mistake?
What
if
that
part,
was
actually
not
parallel,
so
some
compilers
can
issue
a
warning
saying:
are
you
sure
you
want
to
do
that
so
check
your
documentation
to
see
what
your
compiler
has
available?
A
So
what
are
the
advantages
of
local
MP?
It's
a
standard
I
got
a
de
facto
but
widely
endorsed
sense,
and
it's
mature
one
of
the
things
the
language
community
does
is
a
very
careful
in
adding
features.
It
is
all
that
happening
and
just
growing
more
and
more
and
more
avenues
back
every
year,
and
then
everybody
gets
confused
and
nobody's
using
those
features.
A
So
there's
a
lot
of
discussions,
even
though,
like
a
one
clause
on
a
pragmatic
and
have
endless
discussions
which
is
good,
so
that's
what
I
like
they
don't
go
for
the
fashion
of
the
day
like
it
took
long
to
get
the
accelerator
support
in
CC
Numa
support.
The
reason
is
that
it's
hard
to
make
it
abstract
enough
to
be
useful,
understandable
and
portable.
The
easy
way
is
to
throw
all
the
low
level
stuff.
That's
not
what
the
openmp
philosophy
is
about,
so
I
think
that
society
will
see.
A
A
401
drive,
specs
oil
first
rumblings
about
50
have
started
so
it
continues
to
adapt
to
use
Ernie.
You
can
definitely
get
good
performance
and
scalability,
but
you
gotta
do
it
right
and
the
fact
that
I
think
the
language
is
easy
doesn't
actually
mean
that
you
can
be
stupid.
Right,
is
stupid
program
and
will
get
stupid
performance
and
also
don't
make
that
mistake.
But
what
I
like
when
you
have
that
the
moment
from
ipho
implementation
is
usually
pretty
sure?
A
Okay,
but
don't
do
certain
things
that
I'll
talk
about
so
you're
not
off
the
hook,
but
it
is
definitely
definitely
a
scalable
model.
Portability.
I've
said
that
already,
as
I
said,
is
its
effort.
The
programming
effort
is
fairly
modest
but
again
you're
not
on
dope
and
another
thing
that
I
like
when
you're
totally
new
to
this
stuff.
You
can
do
it
step
by
step.
You
just
hackle,
a
very
small
part
of
your
program
in
here
works.
A
John-Boy,
discuss
before
the
overall
performance
may
not
benefit
from
it,
but
it's
very
encouraging
it's
a
very
gradual
model
instead
of
all
of
them.
So
don't
forget
that
this
starts
well
and
eventually,
you'll
probably
realize
that
your
initial
effort
wasn't
the
right
way
to
get
help
with
scalability,
but
it
gets
you
going
and
that's
not
as
in
the
network
and
it
turned
out
openmp,
although
never
designed
the
one
of
multi-core
systems
at
a
time.
A
A
A
The
directives
are
case,
sensitive,
okay
and
the
same,
that
is
pragma
oil
team
and
then
a
directive
like
parallel
or
four
or
task
and
optionally.
Each
directive
has
a
bunch
of
clauses
and
those
are
all
documented
and
I'll
cover
some
of
them
during
this
time.
These
lines
can
sometimes
be
long,
so
you
can
use
the
backslash
as
a
continuation
in
the
pragmatist
and
a
way
to
use
continuation
and
pragma.
So
you
can
break
it
over
multiple
lines.
You
get
the
guarantee
that
is
underscored.
A
Openmp
macro
is
set,
so
you
can
do
an
if
death
on
that
and
make
decision
compile
some
based
on
that
in
fortune,
and
you
always
got
the
issue
of
the
old
style,
ancient
formatting
and
the
free
formatting,
but
so
it
starts
with
either
!
dollar,
o
MP
or
C
dollar,
OMP
or
stock
part
along
p.
What
I,
like
is
the
first
one
!
dog,
because
it
works
in
both
formatting
important
when
you
need
to
fix
formats.
A
Don't
forget
to
put
use
in
the
first
column
course
never
happened
to
me,
but
it
could
happen
to
you
and
the
downside
of
a
directive
is,
if
you
make
a
typo,
that's
truancy
as
well.
It
gets
ignored.
You
think.
Why
doesn't
this
come
on
in
parallel?
Well,
maybe
was
that
fatal
high
for
yourself
again
never
happened
to
me,
but
may
happen
to
you.
A
How
do
you
define
the
parallelism
in
openmp
really
easy,
sometimes
when
I'm
in
more
challenging
mode,
as
you
can
do
a
live
demo,
but
it's
just
as
easy
as
you
identify
a
block
of
code,
whatever
it
is,
and
you
embedded
to
try
my
I
be
parallel
and
see
you
have
these
curly
braces
that
defines
your
ilysm
in
motrin.
You
have
the
OMP
parallel
and
what
I
like
in
the
NFL.
There
is
no
end
parallel
and
see
that
such
a
saint
in
texting
as
a
word
of
warning
and
I,
see
if
I
go
on
this
slide.
A
That
and
I
like
to
end
that
curly
brace
with
some
comment
so
I
know
that
that's
where
my
cell
is
immense,
because
it's
he
program
has
a
lot
of
those
and
that's
probably
curly
brace.
You
want
to
be
careful
with
because
it
defines
where
your
Palace,
immense
and
so
I
use
some
sort
of
marker,
because
it
can
be
quite
obscure.
A
That
simple,
is
that
I'll
talk
a
little
bit
about
various
later
I'm
much
more
in
the
afternoon,
but
a
parallel
region
always
ends
in
a
barrier
in
a
barrier
is
from
winning
you
code,
but
all
threads
wait
until
the
nice
one
has
arrived,
so
that
can
have
an
impact
on
performance
of
course,
and
talk
about
that.
But
that's
always
an
implied
very
at
the
end
of
a
parallel
ridges
and
as
a
good
reason
for
doing
so.
A
A
What
options
there
is
to
recognize
those
those
fragments
I
would
like
them
to
be
automatically
recognized,
but
I,
don't
think
any
competitors
then,
and
I'm
I,
not
income
find
a
person,
but
I
would
say:
okay,
I
type
of
day,
why
don't
you
recognize
it
but
check
your
compiler
documentation,
like
indeed
you
see,
is
an
opening
me.
This
is
from
our
our
studio.
Compiler
we
use
X
openmp
to
I.
Have
those
pragmas
recognized,
otherwise
nothing
will
happen.
A
Okay,
I
guess,
correction
from
having
the
Cray
compiler.
Does
it
by
default?
Okay,
that's
it
I
like
this
again
be
careful
that
I
bows
could
sign
me
more
thing.
Those
are
the
first
gotchas
that
people
run
into
like
it
doesn't
work
yeah
well,
maybe
they're.
Why
I
think
about
middle
okay,
assuming
you
got
it
all
covered.
You
set
the
number
of
pets,
that's
the
number
of
initial
threat
and
in
this
case
I
said
in
22.
A
A
A
If
you
evaluate
even
evaluates
to
false
coronal,
want
it
and
the
key
use
is
to
say
well,
my
my
data
set
is
too
small:
I,
don't
I
don't
want
to
run
in
parallel,
so
I
can
still
have
one
piece
of
source
and
that's
what
I'm
time
to
illustrate
you.
If
the
loop
length
only
in
the
loop
length
exceeds
some
threshold
that
I
define
our
actually
executing
that,
so
that
way,
you
have
one
source
and
then
choose
my
efficiency
around
small
sizes
and
all
architects.
They
convenient
closes
I.
A
Think
I'm,
I'm
not
going
to
show
a
much
more
elaborate
example,
usually
good
for
some
discussion
and
I
call
that
an
airplane
slide.
An
epic
life
is
Lincoln's,
made
up
on
some
long
airplane
ride,
and
it
has
no
scientific
meaning
pedal.
Don't
try
to
be
anything
into
it.
Why
I
would
do
something
like
that?
What
I
want
to
show
you
is
the
flow
of
the
computation
and
how
I
could
paralyze?
So
let's
say
this
is
my
computer.
A
I
initialize
a
variable
have
someone,
then
I
compute
a
vector
Z
than
tons
of
x
and
y
I,
then
compute
event
that
event
on
B
and
C
and
finally,
somewhere
I
want
to
compute
the
scheduler
called
scale
when
summing
up
the
elements
of
a
of
d,
and
that's
that's
what
I'm
doing?
How
would
I
do
that
in
power?
There
are
several
ways
I'll
show
you
my
recommended
way.
A
First
of
all,
we
schedule,
and
that
is
whole
block
in
a
fella
reaches
that's
golden
rule
number
one
for
performance,
you'll,
hear
more
throughout
the
day
minimize
the
number
of
colleges,
hello
region
is
relatively
heavy
in
terms
of
course,
so
we
don't
want
to
have
too
many
parallel
regions.
So
what
I
do
I'm
going
to
define
my
paladin
from
top
to
bottom?
It's
a
bit
like
mb
I.
You
know,
I'm
sure
you
start
off
running
in
parallel.
That's
that's
what
I'm
doing
here
and
ignored
all
these
details
on
them
on
the
pragma.
A
For
now
this
is
my
collagen.
What
it
means
is
that
all
threads
will
execute
F
equals
one
all
threads
will
compute
team.
All
of
them
will
compute
a
all
of
them
in
Connecticut.
That's
probably
not
what
I
want
I
want
that
fine,
then
we're
done
what
if
I
want
to
have
this
one,
this
unit
open
threads
and
this
one
disability
office,
and
this
should
be
done
by
by
once
at
home.
A
A
A
Then
I
get
to
that
loop.
How
do
I
distribute
to
work?
Oh,
that
is
very
convenient,
oh
and
before
NOP
do
in
in
Fortran
compiler
by
the
loop.
So
what
will
happen
here
is
if
n
iterations
will
be
spread
over
the
place.
How
that
is
done,
I
can
fully
control
all
right
here.
I
leave
it
up
to
the
system.
You
figure
out
what
you
want
to
do,
but
if
you
don't
like
the
defaults,
you
can
you.
Can
you
have
a
lot
of
choices
again,
that's
a
long
week
up
so
here
we'll
go
to
the
parallel.
A
Each
set
will
get
a
chunk
of
the
iteration
stick.
I
use
a
feature
that
that
is
I
would
take
advance
with
useful.
It's
called
no
way
it
actually
does
exactly
whatever
it
says.
Reds
won't
wait
when
they're
done
technically
it
won't
be
a
barrier
at
the
end
of
the
loop.
So
what
it
means
is
that
a
jealous
of
thread
it
done
with
whatever
work
has
been
carved
out
with
it
will
continue
and
we'll
get
to
the
next
loop
that
I
want
to
paralyze
the
same
way
again
by
default.
There's
a
barrier
here
so
the
hallway.
A
Why
should
I
wait
because
this
computation,
the
second
computation,
is
independent
of
what
I've
been
doing
so
far
and
berries
are
expensive?
You
want
to
minimize
the
use
so
I
use.
The
know
me
now,
as
I
said
no
way,
there's
no
for
the
beginner,
but
once
you
start
fine-tuning
a
program
is
a
really
nice
cause.
A
You
can
play
with
and
get
better
performance
now,
but
now
we're
going
to
be
careful,
because
if
I
wouldn't
do
anything
they're
all
start
computing
scale,
not
only
that,
what's
the
guarantee
that
a
is
available
because
some
sense
may
take
longer
and
they're
still
working
on
their
computation
while
other
thread
starts
coming
up
all
the
vector
elements,
I
hope
that
problem
is
clear.
I
can't
see
all
these
other
people
long
as
I
hope,
I
hope.
You
all
agree
that
this
give
me
a
romance.
A
A
So
that's
that's
wrong.
Doing
it
a
problem
with
OpenMP
in
a
way
is
often
there
multiple
ways
to
implement
the
balances.
Usually
there
is
only
one
that's
right
for
performance,
but
it
works.
So
again,
that's
part
of
the
performance
session
this
afternoon,
so
this
is
this
is
the
way
I
like
to
write
it
now
about
that
pragma
I.
A
A
That
means
that
I
need
to
specify
where
variables
go
and,
as
I
said
a
while
ago
and
open
if
you
have
two
types
of
memory
shared
and
private
and
I'll
get
back
to
that
little
later,
but
in
this
case
I
want
to
have
the
arrays
accessible,
the
vectors
accessible
by
call
so
I
make
them
shared,
and
the
scalars
are
private
to
be
spread.
Who
get
it
on
more
on
that
very
soon,
but
that's
how
how
you
would
do
that
so
I
was
this
is
about
as
complicated
as
in
temperature.
A
Most
okay,
here's
one
thing
as
only
one
slide
and
some
I
never
know
where
to
put
it
so
I,
just
dump
it
dumped
in
here
and
it's
not
super
business.
Nationalism
has
been
an
open.
It
me
from
day
one,
although
not
really
talk
through
when
they
first
could
begin,
but
the
idea
was
we
need
to
handle
recursive
algorithms.
So
what
you
do
in
the
parallel
region
use
chance.
A
Another
parallel
region,
ain't,
no
parallel
again
and
again
and
again
and
again,
if
you
want
god
bless,
is
valid
and
suggested
he
initially
that
the
number
of
fans
explodes
pretty
quickly.
So
these
days
you
have
more
control
to
specify
how
many
31
and
actually,
in
many
cases
where
r
s
apparel
is
introduced.
Hiking
is
a
better
solution.
Attached
thing
is
for
after
the
break,
but
it's
there
and
it's
I
want
to
mention
it.
A
Okay,
go
back
a
little
higher
level.
What
do
I
get
when
I
when
I
start
using
on
baby
watch
my
toolbox,
my
toolbox
consists
of
the
directives
the
directives
to
and
share
the
work
like
the
loop.
I
was
showing
that's
what
the
work
sharing
directive
to
all
the
fans
share
the
work
and
they
figure
out
who
does
what
but
work
sharing.
That's
a
system
called
asking.
You
get
controls
over
thread
affinity.
You
can
mass
in
your
accelerator.
A
You
can
cancel
a
thread
if
there's
some
problem
and
you
get
primitives
to
do
the
synchronization.
That's
what
you
get
at
a
directive.
Look
at
the
environment,
variable
level.
You
can
set
also
the
things
about
the
sense
like
the
number
of
beds
you
can
control.
What's,
let's
do
example,
if
there's
no
work
for
them.
What
do
you
want
with
what
I'm
going
to
do
with
idle
fits?
You
can
control
how
you
want
to
have
the
work
schedule,
affinity,
decide
affinity,
you
can
say
things
about
acceleration
cancellation
and
the
whole
operational
thing
example
is
sex
act.
A
I
doubt
that
I
will
talk
about.
Random
functions
are
very
similar
to
the
environment
variables.
The
idea
is
that
most
things
you
set
with
the
environment
variables
can
be
clearly
at
runtime
and
changed
yeah.
Well,
that
was
my
initial
setting,
but
now
I
want
to
change
it.
They
get
runtime
functions
too.
I.
A
Already
mentioned
this
a
few
times
now,
it's
time
to
go
into
it
more
detail,
fill
every
model
that
small
as
a
lifetime
topic,
but
I'll
keep
it
short
him,
because
it's
not
what
you
know.
It's
not
all
that
much.
You
need
to
know.
What
do
you
have
you
have
a
pool
of
threads
and
each
thread
will
see
the
same
shared
memory.
A
There's
only
one
chairman
and
I
stressed
that,
because,
when
you
have
a
digital
memory
background
that
that
is
like
it's
a
different
thing,
I
noticed
over
time
that
questions
arise
from
misconception
about
the
memory
model.
So
there's
one
shared
memory
and
in
addition
to
that,
each
thread
will
have
a
private
moment.
A
What's
the
difference,
the
difference
is
that
whatever
anklet
does
to
private
memory.
Just
like
that
then
bi
memory
model.
Nobody
else
will
see.
Remember
my
valuable
f.
I
said
it
to
one.
Nobody
else
will
no
doubt
I
could
sell
you
any
value
and
there's
no
interference
all
threads
get
on
go.
The
difference
is
the
shared
memory.
Engine
revving
there's
only
one
instance
of
the
variable
all
threads.
We
can
read
it
right
at
any
moment
in
time
and
sup
to
you
basically
to
make
sure
that
happens
at
the
high-tech
redesigned
vehicles
and
they
communicate
through
ship.
A
If
I
have
available
that
I
want
to
make
available
to
another
thread
it
has
to
be
in
shipment.
You
know
I
copy
it
from
my
private
memory
into
the
shared
memory
or
I
put
it
in
shape
memory
from
the
start.
The
choice
is
yours,
that's
that's.
How
does
automatic
model
work
and
again
if
modify
the
value
of
a
shared
memory
after
a
while
everybody
else
will
see
and
our
own
purpose
I
said
after
a
while,
because
I
have
to
talk
about
that
as
well,
when
these
changes
are
visible.
A
So
that's
a
new
thing
when
you
new
to
this
kind
of
programming
is
that
each
and
every
variable
you
need
to
label
the
data
you
need,
you
think
about
all
your
variables
should
have
able
to
be
shared,
or
should
it
be
private
and
that's
part
of
the
learning
curve
now
Oh
bleep
it
has
default
rules
for
them.
I
consider
them
to
be
broken,
I,
don't
understand
them
and
they're
toting.
So
don't
ask
me
about
the
default
rules.
Think
about
yourself.
It's
a
really
good
practice
to
do
that
yourself.
A
First
of
all,
you
want
you
want
to
minimize
the
use
of
share
data
for
performance,
bring
convenience
you
have,
but
the
excessively
share
data,
if
you
can
avoid
it
and
just
good
practice
to
think
about
it
yourself,
it's
okay,
this
this
way
will
should
be
shared,
and
this
one
should
be
part,
and
especially
after
you've
seen
some
examples.
You
give
it
a
try.
You'll
find
it's
not
that,
and
the
reward
is
internet.
If
you
want
to
rely
on
the
default
rules,
call
your
lawyer,
don't
call
me
because
again,
I
think
they're,
very,
very
subtle.
A
That's
probably
the
politically
correct
way
to
say,
but
that's
why
I
use
and
I
kind
of
jumped
over
that
whole
purpose.
The
default
none
Clause
a
default.
None
forces
me
the
compatible
flag,
any
variable
that
it
is
especially
now.
That's
too
much
for
you
there's
other
ways
around
it.
I'll
point
it
out,
but
again
I've
seen
too
many
people
being
bitten
buying
those
subtleties,
that's
as
easy,
as
shown
here.
How
do
you
do
that
private
and
a
list
of
variables
and
shared
analista
variables
and
data
shared
is
pretty
straightforward.
A
A
By
side,
that's
actually
what
you
want.
As
a
result,
private
variables
are
undefined
on
entry
and
exit.
So
you
have
to
see
the
gift
of
value
or
use
the
first
private
law
set
up
acaba,
but
keep
that
in
mind.
These
are
some
important
rules
for
private
variables
and
that's
what
is
you
said:
that's
a
big
one,
private
variables
of
undefined
on
entry
and
exit,
and
if
that's
not
what
you
want,
you
can
use
the
first
private
to
pre,
initialize
private
variables
and
the
last
private
is
to
save
payroll
out
of
a
bellows.
A
So
you
have
a
way
up.
It's
just
not
the
people
and
it's
very
little
need
actually
for
for
these
things.
So
again,
very
simple
food,
private
you
put
in
a
list
of
Abel's
in
all
these
variables
for
each
thread
will
be
initialized
to
the
value
they
had
outside
of
the
pella
reach.
So
crebbil
a
had
a
value
of
10
I
declare.
First,
private,
a
all
threads
will
get
a
pre-initialized
value
of
10
could
be
very
useful.
So
it's
not
that
we
do
need
to
do
something
complicated.
You
think
about.
A
First,
five
last
driving
is
a
little
more
special
think
about.
The
word.
Lack
last
has
no
meaning
in
a
parallel
program,
because
the
order
is
not
defined
so
depends
on
the
corner.
Each
constructs
has
a
well-defined
interpretation
of
last
private.
The
loop
is
easy
because
that
corresponds
to
the
last
iteration
executed.
That's
the
value
that
you
get
out
with
other
constructs
its
defined,
but
you
have
to
think
about
what
this
last
meeting
you
I
kind
of
crafted
a
little
example
on
the
first
private
I'll.
Do
that
very
quickly?
A
A
This
is
a
private
variable.
Again,
each
each
set
will
have
its
own
value.
The
fact
that
after
the
initial
launch
index
will
be
different
depending
on
the
thread
idea
is
ok
because
they
all
have
their
own
goal.
So
that's
how
you
play
and
use
private
variables
to
get
to
your
goal
and
first
drive
it
in
come
in
really
handy
again.
Most
often
you
don't
need
it,
but
if
you
need
it,
it's
convenient
convenient
class
drive
it.
The
simple
case
is
a
look
to
preserve
the
sequential
semantics.
A
The
last
private
value
of
a
is
the
one
that
corresponds
to
the
loop
iterations.
I
equals
n
minus
1.
It's
what
your
sequential
program
will
do.
So
we
preserve
them
mind.
There
is
a
small
cost.
Sweta
I
things
for
free.
The
rental
system
will
have
to
handle
these
usually
care.
But
if
you,
if
you
need
it,
is
very
convenient.
A
Ok
there
we
go.
The
default
I
already
mentioned
default,
one
you
can
also
say
default.
Shared
I
would
recommend
doing
them
because
again
for
performance.
Excessively
sharing
data
is
not
a
good
idea
of
default,
said
it
wouldn't
be
mine
again.
The
look.
The
scoping
of
the
Bible's
is
not
hard
in
for
time.
You
have
some
more
choices.
I
got
the
language
rules
why
there
is
no
default
private
in
C++.
A
That's
not
there's
not
a
typo
on
this
slide
is
not
available
and
I'm
again,
I
use
the
boatmen
and
you
choose
whatever
your
electricity.
So
I
talk
a
lot
about
private
data.
That's
time
to
talk
about,
share
data
and
absolutely
this.
This
is
a
big
part
of
the
runner.
You
kind
of
get
this
right.
If
you
get
it
wrong,
okay,
romance
oakland
p
is
pretty
ruthless
in.
Doesn't
you
want
to
have
a
private
variable?
Give
you
a
prime
example:
it's
up
to
you
to
make
the
right
choice.
A
Chad
is
a
little
kind
of
special
because,
because
of
the
way,
a
computer
intrudes
work
these
days
a
lot
of
asynchronous
of
case
going
on
in
the
system.
So
what
the
specifications
allow
is
that
the
same
shared
valuable
can
have
different
values
for
a
while
and
it's
very
well
defined,
and
when
that
value
should
be
resynchronize
so
all
set
to
the
same
value
again
and
that
enforced
by
zero
flush
and
it
implied
or
medical,
so
I
don't
want
I,
don't
want
to
certainly
not
at
ten
fifteen
in
the
morning.
A
Here's
a
fairly
advanced
way
of
Bella
programming,
a
big.
What
I
setting
up
I
have
two
lives
and
one
place,
but
a
is
in
charge
of
shared
variable
called
X
and
it
shift,
and
what
I
want
is
the
other
thread
or
threads
will
wait
for
that
variable
to
change.
It's
like
a
flag
changes.
I
want
to
do
something.
A
Now,
here's
the
problem,
this
program,
selling,
x,
20
and
a
certain
point
will
change
to
one.
What
I
want
is
this
one
to
trigger
over?
So
you
got
this
comparative
because
the
implanted
like
to
optimize
your
program
as
much
as
they
can,
and
that
means
that
they
like
to
keep
variables
in
registers,
that
is
it.
Changes
are
not
seen
by
other
plan.
A
So
if
this
program
is
fairly
well
optimized
that
changes
in
a
register
not
any
cash,
yes
and
this
level
may
never
see
that
change,
and
it
will
hang
that's
being
a
notorious
problem
in
chef
Mary
programming
from
day
one.
Is
it
not
new
to
openmp?
What
open
Aziz
has
done
is
formalized
a
solution
to
this
part,
which
is
a
good
thing
before
that
you
need
to
have
acts
like
and
see.
You
would
declare
variables
volatile,
so
I
can
compiler
would
roll
and
store
the
value
all
the
time
to
make
sure
it
gets
the
right
out.
A
That's
overkill
that
cost
you
a
lot
of
performance
so
think
about
this.
I
had
a
special
scenario
and
here's
a
is
one
from
the
example
set
that
I
mentioned
a
while
ago,
the
ones
you
can
download.
That's
that's
by
far
the
most
complicated
example
where
I
have
a
flag
waiting
for
something
to
finish:
it's
actually
waiting
for
an
I/o
operation
to
be
completed
and
what
it
does
in
a
while
loop.
It
will
need
an
array
element,
execution,
state
I,
and
it
will
wait
for
that
to
change.
So
it
is
not
be
finished.
A
It
will
just
cook
them
in
the
sleep
kind
of
reflect,
so
it
will
awaken.
Now
this
is
exactly
the
problem
that
I
just
pointed
out
with
my
variable
X.
Some
plans
will
change
this
value.
Presumably
how
does
here
that
says?
No
that's
the
same
problem
and
with
open
until
you
get
the
flush
to
actually
flush
the
variables
back
into
the
memory
here
are
king
and
all
changes
are
visible
to
all
clicks
and
that's
called
the
temporary
view.
A
While
it's
different
and
after
that,
you
globalize
the
variable,
they
all
have
the
same
value
again
so
by
forcing
the
brush
I
know
that
I'll
get
the
most
accurate,
most
recent
value
of
that
back
again,
a
little
sophisticated.
You
don't
need
that
Malaysia
do
special
things,
but
I
thought
is
a
natural
movement
way
to
show
up.
I,
don't
need
the
flush
here
for
those
of
you
interested
in
this
kind
of
program.
A
I
need
it,
because
the
next
time
I'll
means
I
need
to
make
sure
that
every
right
I
do
it
initially,
but
I
have
to
do
it
more
than
initially
and
actually
the
one
writing.
This
variable
needs
to
do
to
flush
it
well
so
vine,
it
back
into
the
memory
him,
so
I
needed
on
bolsa
again.
Plush
is
not
for
the
faint
of
heart,
but
it's
very
various
in
those
cases.
So
you
need
it.
A
You
get
rid
of
all
sort
of
uncertainties
about
compilers
optimizing,
so
I
really
like
it,
but
again,
not
for
the
faint
of
heart,
and
there
are
some
other
things
you
can
probably
want
to
read
up
on
subjective
specifications.
If
you
want
to
use
the
push,
the
one
thing
that
I
think
we
discourage
is,
you
can
selectively
specify
variables
and
that
gets
really
tricky
and
I.
Actually
in
the
book,
I
put
an
example:
how
tricky
that
can
be!
Don't
don't
use
the
list
to
a
global
flush
of
all
the
variables
or
don't
use
it
at
all.
A
Once
you
start
playing
with
individual
medals,
you
really
have
to
know
a
lot
about
how
compilers
behave
now,
what
the
rules
are
so
try
to
stay
away
from
I
think
a
certain
point
with
even
consider
to
remove
it,
but
that
will
break
a
code
and
we
don't
to
do
that
and
so
forth,
but
we
can
okay.
What
about
the
memory
already,
as
I
promised
in
my
introduction
in
the
introduction?
Oh
go
higher
level
again
until
we
can
before
dessert.
So
how
does
the
program
an
open
up
a
program
executes?
A
There's
always
one
thread
running:
you
start,
you
program
is
always
one
thread
running
from
start
to
finish
and
that's
called
the
master
so
always
on.
Is
that
and
when
your
monitor
your
program,
they
talk?
Was
a
mother
told
el
sadat
running
at
a
certain
point
when
it
hits
the
parallel
region,
the
other
threads
are
engaged,
that's
where
you
go
parallel
and
have
a
work
with
the
table.
Example
at
the
end
of
the
pair
region.
They
wait,
there's
an
implied
very
early
flight
synchronization.
A
That
begs
the
question:
what
do
you
do?
Well,
there's
no
good
for
these
other
events
and
that's
under
control
of
an
environment
of
very
vocal
OMP,
wait
policy,
passive
or
active.
Basically,
what
that
means
is
very
intensive.
It
will
release
the
hardware
back
to
the
system,
saying
I,
don't
need
it
for
a
while.
You
use
it
for
something
else.
That's
a
very
social,
friendly
approach.
The
active
approach
is
I'll,
just
keep
it
nobody
else.
Catches
I
got
nowhere
crazy,
I'll,
keep
it
and
you
get
the
choice
and
the
50
message
had
people.
A
A
I,
like
I
like
to
use
it,
but
if
you
want
to
stay
fully
standard
to
find
use
only
way,
policy,
passive
or
active,
and
you
hope,
the
implementation,
those
event
in
which
we
expected
okay,
so
something
that
I
mentioned
a
couple
of
times
already
and
I'm
sure
many
of
you
are
familiar
with.
It
is
the
berry
and
I
always
said
what
it
is.
Why
do
you
need
plays
an
example?
A
I
have
to
lose
loop
number
one
computes
a
and
look
number
to
compute
be
using
egg
if
I
would
run
it
in
parallel
without
doing
anything
special.
My
claim
is
one
day.
I'll
get
a
wrong
answer
and
again,
I
promised
not
to
ask
questions
to
the
audience,
but
why
well
there's
an
applied
assumption.
Assumption
is
that
a
of
I
is
available
whenever
the
threat
executing
the
second
you'll
need
you
well
things
bear
alone,
that's
a
hard
part
about
parallel
computing.
What
guarantees
do
I
have
I?
A
Don't
the
bed
that's
supposed
to
what
they
day
of
I
may
have
not
done
so
you.
So
all
these
tales
value
instead
of
beluga,
that's
actually
called
the
database
when,
when
you
have
it
disconnect
between
reading
and
writing,
shared
variables,
I'll
say
more
about
databases
later
with.
It
is
an
example
of
the
database.
A
So
what
you
really
want
is
all
of
a
should
be
computed
before
I
move
on
to
the
next
one,
that
a
simple
solution
would
be
to
fuse
these
two
loops
into
one
and
have
that
guarantee
there's
other
ways.
But
if
you
can't
or
don't
want
to
do
that,
you
can
put
in
a
barium
to
enforce
completion
of
all
the
work
here
before
moving
on
to
limits,
and
that's
why
every
ll,
Lupin
openmp
has
a
very
and
that's.
A
Why
I
like
the
no
way,
because
very
often
you
don't
mean
so
as
part
of
the
fine-tuning
you
put
in
your
pragmas,
you
got
the
right
result
and
then
you
start
looking
for
opportunities.
We
use
no
way
to
eliminate
the
very
I.
Don't
think
of
pilots
have
gotten
to
do
that,
for
you
get
and
you
take
control
and
use
the
no
way.
A
Ok,
that's
the
barrier,
but
the
behavior
name
is
like
this:
let's
get
into
the
berry
region
starts
waiting
at
that
point
is
known
how
many
players
should
enter
the
feria
region
and
it
they'd
all
start
waving
or
their
way,
they'll
wait
until
the
next
one
arrives
and
they
continue
and
on
purpose.
I
may
despise
so
that
you
think
this
is
a
great
opportunity
for
wasting
cycles.
A
12
load
balance
problem,
but
don't
finish
at
the
same
time,
so
barriers
are
the
ones
you
want
to
use
the
care
and
again
their
weight
around
yes,
but
certainly
gets
you
the
right
result.
Oh
and
the
berry
is
one
example
that
has
an
implied
flush
with
the
barrier,
all
shared
rains
or
synchronizing,
and
then
actually
and
the
say
that
is
really
eating
travel
or
the
barrier
oil
fortran
OMP
back
when
you,
when
you
want
to
use
them
well
again,
it
is.
A
A
And
in
a
way
somebody
said
a
lot
about
it
because
of
sin:
tax
issues,
you
put
it
out
there
at
the
top
of
the
loop
example
and
a
fortune
at
the
end
as
a
more
logical
place,
but
you
can
do
that
in
c,
because
it's
in
do
so.
I
think
this
funny
way
yeah
this
this
was,
it
is
part
of
the
mail
elevator
right,
11,
I,
know
and
we'll
have
a
break
now.
Yeah
we'll
have
a
missing
a
minute
baby
back
1047.