Hi Elias,
I have added a new FILE_IO function that reads an entire file in one go.
I also inlined the functions related to the reference counter. SVN 223.
It is quite normal that a considerable fraction of the execution time is
spent
on value creation or cell initialization if there are no other
heavy-weight calculations
are performed (which is the case if you read a file, for example).
/// Jürgen
On 04/25/2014 12:45 PM, Elias Mårtenson wrote:
Fair enough, but the problem with the cell allocations is that they
alone represent 37% of the run time. The clone calls (of which the
cell initialisation is part) is 70%. It's clear that reducing the
number of clone calls is key. The way to do that is to make sure that
the copy-on-write semantics are stable and working.
Then the is the issue of the reference counter. 26% of the time is
spent manipulating that. Perhaps moving to the Böhm collector is
something to investigate...
Regards,
Elias
On 25 April 2014 18:36, Juergen Sauermann
<juergen.sauerm...@t-online.de <mailto:juergen.sauerm...@t-online.de>>
wrote:
Hi,
just to mention it, cells are not allocated by their constructor
because
for cells "placement new" is always used. The allocation of all
ravel cells is
done by the Value constructor.
So the 2.2 billion "allocations" are actually 2.2 billion ravel
cell initializations
(without involving memory allocation for each cell).
I will nevertheless look into this; I was earlier thinking of a
new FILE_IO function
that returns an entire file.
/// Jürgen
On 04/25/2014 08:01 AM, Elias Mårtenson wrote:
Actually, no. I don't actually do that. I only resize the array
one every 1000 lines (configurable). Also, the time is not spent
there.
As I mentioned, I ran it under Callgrind, and the time spent
allocating arrays is actually minimal. What does take time is the
2.2 /billion/ cell allocations and the 50 /million/ calls to
Value::clone(). Most of these calls clone a value that that is
immediately discarded afterwards.
The solution is to avoid cloning of values that are not stored
(that's the core of the "temp" idea). Right now the temp system
is only used in some very specific cases, but once that can be
used for Value::clone() is when we'll see the big performance boosts.
Regards,
Elias
