[pypy-commit] extradoc extradoc: (fijal, arigo) start working on slides

[fijal]

Author: Maciej Fijalkowski <fijall at gmail.com>
Branch: extradoc
Changeset: r5441:e25d84db6be0
Date: 2014-10-18 15:47 +0200
http://bitbucket.org/pypy/extradoc/changeset/e25d84db6be0/

Log:	(fijal, arigo) start working on slides

diff --git a/talk/pyconpl-2014/benchmarks/abstract.rst b/talk/pyconpl-2014/benchmarks/abstract.rst
new file mode 100644
--- /dev/null
+++ b/talk/pyconpl-2014/benchmarks/abstract.rst
@@ -0,0 +1,7 @@
+How to benchmark code
+---------------------
+
+In this talk, we would like to present basics of how the Python virtual machines
+like CPython or PyPy work and how to use that knowledge to write meaningful
+benchmarks for your programs. We'll show what's wrong with microbenchmarks
+and how to improve the situation.
diff --git a/talk/pyconpl-2014/benchmarks/f1.py b/talk/pyconpl-2014/benchmarks/f1.py
new file mode 100644
--- /dev/null
+++ b/talk/pyconpl-2014/benchmarks/f1.py
@@ -0,0 +1,8 @@
+
+def f():
+    i = 0
+    while i < 100000000:
+        i += 1
+    return i
+
+f()
diff --git a/talk/pyconpl-2014/benchmarks/f2.py b/talk/pyconpl-2014/benchmarks/f2.py
new file mode 100644
--- /dev/null
+++ b/talk/pyconpl-2014/benchmarks/f2.py
@@ -0,0 +1,10 @@
+
+def f():
+    i = 0
+    s = 0
+    while i < 100000000:
+        s += len(str(i))
+        i += 1
+    return s
+
+print f()
diff --git a/talk/pyconpl-2014/benchmarks/fib.py b/talk/pyconpl-2014/benchmarks/fib.py
new file mode 100644
--- /dev/null
+++ b/talk/pyconpl-2014/benchmarks/fib.py
@@ -0,0 +1,27 @@
+
+import time
+import numpy
+from matplotlib import pylab
+
+def fib(n):
+    if n == 0 or n == 1:
+        return 1
+    return fib(n - 1) + fib(n - 2)
+
+def f():
+    for i in range(10000):
+        "".join(list(str(i)))
+
+times = []
+for i in xrange(1000):
+    t0 = time.time()
+    #f()
+    fib(17)
+    times.append(time.time() - t0)
+
+hist, bins = numpy.histogram(times, 20)
+#pylab.plot(bins[:-1], hist)
+pylab.ylim(ymin=0, ymax=max(times) * 1.2)
+pylab.plot(times)
+#pylab.hist(hist, bins, histtype='bar')
+pylab.show()
diff --git a/talk/pyconpl-2014/benchmarks/talk.rst b/talk/pyconpl-2014/benchmarks/talk.rst
new file mode 100644
--- /dev/null
+++ b/talk/pyconpl-2014/benchmarks/talk.rst
@@ -0,0 +1,78 @@
+---------------------
+How to benchmark code
+---------------------
+
+Who are we?
+------------
+
+xxx
+
+What is this talk is about?
+---------------------------
+
+* basics how CPython and PyPy run programs
+
+* a bit of theory about measuring performance
+
+* microbenchmarks
+
+* complicated picture of "real world"
+
+CPython
+-------
+
+* a "simple" virtual machine
+
+* compiles python code to bytecode
+
+* runs the bytecode
+
+* usually invokes tons of runtime functions written in C
+
+CPython (demo)
+--------------
+
+PyPy
+----
+
+* not so simple virtual machine
+
+* all of the above
+
+* ... and then if the loop/function gets called often enough
+  it's compiled down to an optimized assembler by the JIT
+
+PyPy (demo)
+-----------
+
+Measurments 101
+---------------
+
+* run your benchmark multiple times
+
+* the distribution should be gaussian
+
+* take the average and the variation
+
+* if the variation is too large, increase the number of iterations
+
+Let's do it (demo)
+------------------
+
+Problems
+--------
+
+* the whole previous slide is a bunch of nonsense
+
+* ...
+
+"Solution"
+----------
+
+* you try your best and do the average anyway
+
+* presumably cutting off the warmup time
+
+|pause|
+
+* not ideal at all