Regenerate remove_default_chunk_size.patch for current version, add a note at the top to not use without changing your usage patterns as well, otherwise significant loss of performance. Probably is not ready for use at all yet, still needs some work on performance issues.

Author: kata198

remove_default_chunk_size.patch

@@ -1,10 +1,14 @@
+This will remove the default chunk size for each priority level.
+
+Do not yet use, this is a work-in-progress, and if you do not specify explicit chunk sizes, you will suffer a significant drop in performance.
+
 diff --git a/nonblock/BackgroundWrite.py b/nonblock/BackgroundWrite.py
-index efb15ea..26932e3 100644
+index 8b9765c..b76cc28 100644
 --- a/nonblock/BackgroundWrite.py
 +++ b/nonblock/BackgroundWrite.py
-@@ -18,8 +18,9 @@ __all__ = ('BackgroundWriteProcess', 'BackgroundIOPriority', 'bgwrite', 'bgwrite
- 
- DEBUG = False
+@@ -26,8 +26,9 @@ __all__ = ('BackgroundWriteProcess', 'BackgroundIOPriority', 'bgwrite', 'bgwrite
+ # Uncomment the "DEBUG" sections you want to see below. Search for DEBUG.
+ #DEBUG = False
 
 +_SIZE_MEG = 1024 * 1024
 
@@ -13,7 +17,7 @@ index efb15ea..26932e3 100644
      '''
          bgwrite - Start a background writing process
 
-@@ -38,7 +39,7 @@ def bgwrite(fileObj, data, closeWhenFinished=False, chainAfter=None, ioPrio=4):
+@@ -46,7 +47,7 @@ def bgwrite(fileObj, data, closeWhenFinished=False, chainAfter=None, ioPrio=4):
              @return - BackgroundWriteProcess - An object representing the state of this operation. @see BackgroundWriteProcess
      '''
 
@@ -22,7 +26,7 @@ index efb15ea..26932e3 100644
      thread.start()
 
      return thread
-@@ -57,9 +58,9 @@ def bgwrite_chunk(fileObj, data, chunkSize, closeWhenFinished=False, chainAfter=
+@@ -65,9 +66,9 @@ def bgwrite_chunk(fileObj, data, chunkSize, closeWhenFinished=False, chainAfter=
 
          @param chunkSize <integer> - The max siZe of each chunk.
      '''
@@ -34,7 +38,7 @@ index efb15ea..26932e3 100644
 
 
  class BackgroundIOPriority(object):
-@@ -69,9 +70,9 @@ class BackgroundIOPriority(object):
+@@ -77,9 +78,9 @@ class BackgroundIOPriority(object):
              See __init__ for fields
      '''
 
@@ -46,7 +50,7 @@ index efb15ea..26932e3 100644
          '''
              __init__ - Create a BackgroundIOPriority. 
 
-@@ -81,12 +82,6 @@ class BackgroundIOPriority(object):
+@@ -89,12 +90,6 @@ class BackgroundIOPriority(object):
              @param chainPollTime - float > 0, When chaining, this is the sleep time between checking if prior is finished.
                  Too low and the polling takes up CPU time, too high and you'll lose a little time in between chained writes, while gaining interactivity elsewhere.
 
@@ -59,7 +63,7 @@ index efb15ea..26932e3 100644
                A high number means higher throughput at the cost of lest interactivity for other tasks, a low number means the opposite.
 
                So, for example, a bandwidthPct of "50" will attempt to use "50%" of the available bandwidth. Note, this does not represent theroetical
-@@ -99,7 +94,7 @@ class BackgroundIOPriority(object):
+@@ -107,7 +102,7 @@ class BackgroundIOPriority(object):
                See #bandwidthPct for the other half of the story. The higher this number, the more "fair" your application will be against a constant
                rate of I/O by other applications, but the less able it may be to play fair when the external I/O is spiking.
 
@@ -68,46 +72,42 @@ index efb15ea..26932e3 100644
                but you may want to tune it if you use really large or really small chunk sizes.
 
 
-@@ -108,7 +103,6 @@ class BackgroundIOPriority(object):
+@@ -116,7 +111,6 @@ class BackgroundIOPriority(object):
 
 
          self.chainPollTime = chainPollTime
 -        self.defaultChunkSize = defaultChunkSize
          self.bandwidthPct = float(bandwidthPct)
          if bandwidthPct <= 0 or bandwidthPct > 100:
              raise ValueError('Given bandwidthPct %f must be > 0 and <= 100')
-@@ -126,20 +120,19 @@ class BackgroundIOPriority(object):
-         raise KeyError('Unknown key: %s\n' %(key,))
-         
- 
--_SIZE_MEG = 1024 * 1024
+@@ -138,16 +132,16 @@ _SIZE_MEG = 1024 * 1024
 
  # BG_IO_PRIOS - Predefined I/O priorities, 1-10. The lower the number, the more throughput at the cost of interactivity
  BG_IO_PRIOS = {
 -    1  : BackgroundIOPriority(.0009, _SIZE_MEG * 5,    100), # Maximum throughput, no regard for interactivity.
 -    2  : BackgroundIOPriority(.0009, _SIZE_MEG * 4,     90),
--    3  : BackgroundIOPriority(.0015, _SIZE_MEG * 3,     80),
--    4  : BackgroundIOPriority(.0015, _SIZE_MEG * 2,     75),
--    5  : BackgroundIOPriority(.0019, _SIZE_MEG * 1.25,  65),
--    6  : BackgroundIOPriority(.0019, _SIZE_MEG * .6,   55),
--    7  : BackgroundIOPriority(.0024, _SIZE_MEG * .4,    45),
--    8  : BackgroundIOPriority(.0024, _SIZE_MEG * .25,   35),
--    9  : BackgroundIOPriority(.0031, _SIZE_MEG * .175,  31),
--    10 : BackgroundIOPriority(.0100, _SIZE_MEG * .1,    25), # Least throughput, most interactivity, very little throughput
-+    1  : BackgroundIOPriority(.0009, 100), # Maximum throughput, no regard for interactivity.
-+    2  : BackgroundIOPriority(.0009,  90),
-+    3  : BackgroundIOPriority(.0015,  80),
-+    4  : BackgroundIOPriority(.0015,  75),
-+    5  : BackgroundIOPriority(.0019,  65),
-+    6  : BackgroundIOPriority(.0019, 55),
-+    7  : BackgroundIOPriority(.0024,  45),
-+    8  : BackgroundIOPriority(.0024,  35),
-+    9  : BackgroundIOPriority(.0031,  31),
-+    10 : BackgroundIOPriority(.0100,  25), # Least throughput, most interactivity, very little throughput
+-    3  : BackgroundIOPriority(.0015, _SIZE_MEG * 3,     78),
+-    4  : BackgroundIOPriority(.0015, _SIZE_MEG * 2,     72),
+-    5  : BackgroundIOPriority(.0019, _SIZE_MEG * 1.6,   65),
+-    6  : BackgroundIOPriority(.0019, _SIZE_MEG * .75,   55),
+-    7  : BackgroundIOPriority(.0024, _SIZE_MEG * .69,   45),
+-    8  : BackgroundIOPriority(.0024, _SIZE_MEG * .5,    35),
+-    9  : BackgroundIOPriority(.0031, _SIZE_MEG * .3,    30),
+-    10 : BackgroundIOPriority(.0100, _SIZE_MEG * .25,   20), # Least throughput, most interactivity, very little throughput
++    1  : BackgroundIOPriority(.0009,  100), # Maximum throughput, no regard for interactivity.
++    2  : BackgroundIOPriority(.0009,   90),
++    3  : BackgroundIOPriority(.0015,   78),
++    4  : BackgroundIOPriority(.0015,   72),
++    5  : BackgroundIOPriority(.0019,   65),
++    6  : BackgroundIOPriority(.0019,   55),
++    7  : BackgroundIOPriority(.0024,   45),
++    8  : BackgroundIOPriority(.0024,   35),
++    9  : BackgroundIOPriority(.0031,   30),
++    10 : BackgroundIOPriority(.0100,   20), # Least throughput, most interactivity, very little throughput
  }
 
 
-@@ -157,7 +150,7 @@ class BackgroundWriteProcess(threading.Thread):
+@@ -165,7 +159,7 @@ class BackgroundWriteProcess(threading.Thread):
      '''
  # Design question: What about errors?
 
@@ -116,7 +116,7 @@ index efb15ea..26932e3 100644
          '''
              __init__ - Create the BackgroundWriteProcess thread. You should probably use bgwrite or bgwrite_chunk instead of calling this directly.
 
-@@ -171,6 +164,12 @@ class BackgroundWriteProcess(threading.Thread):
+@@ -179,6 +173,12 @@ class BackgroundWriteProcess(threading.Thread):
 
              @param ioPrio <int/BackgroundIOPriority> - If an integer (1-10), a predefined BackgroundIOPriority will be used. 1 is highest throughput, 10 is most interactivity. You can also pass in your own BackgroundIOPriority object if you want to define a custom profile.
 
@@ -129,7 +129,7 @@ index efb15ea..26932e3 100644
 
              @raises ValueError - If ioPrio is neither a BackgroundIOPriority nor integer 1-10 inclusive
                                 - If chainAfter is not a BackgroundWriteProcess or None
-@@ -187,7 +186,8 @@ class BackgroundWriteProcess(threading.Thread):
+@@ -195,7 +195,8 @@ class BackgroundWriteProcess(threading.Thread):
                  raise ValueError('Invalid ioPrio: %s. Available priority levels are: %s' %(str(ioPrio), str(list(BG_IO_PRIOS.keys()))) )
 
          if type(dataBlocks) not in (list, tuple):