M.-A. Lemburg wrote:
> On 2008-02-07 14:09, Andrew MacIntyre wrote:
>> Probably in response to the same stimulus as Christian it occurred to me
>> that the freelist approach had been adopted long before PyMalloc was
>> enabled as standard (in 2.3), and that much of the performance gains
>> between
On 2008-02-08 08:21, Martin v. Löwis wrote:
>> One of the hopes of having a custom allocator for Python was to be
>> able to get rid off all free lists. For some reason that never happened.
>> Not sure why. People were probably too busy with adding new
>> features to the language at the time ;-)
>
Andrew MacIntyre wrote:
> However, my tests do show that something is funny with the current
> freelist implementation for floats on at least 2 platforms, and that
> doing without that sort of optimisation for float objects would likely
> not be a hardship with PyMalloc.
float objects are slightly
Andrew MacIntyre wrote:
> For the int case, that patch is slower than no free list at all. For the
> float case its very slightly faster (55.3s vs 55.5s) than no free list at
> all. Slower than the trunk code for both cases. Did you run the test
> scripts on your own machine?
I've used a simple
On Feb 8, 2008 10:54 AM, Christian Heimes <[EMAIL PROTECTED]> wrote:
> Andrew MacIntyre wrote:
> > However, my tests do show that something is funny with the current
> > freelist implementation for floats on at least 2 platforms, and that
> > doing without that sort of optimisation for float object
Tim Peters wrote:
> pymalloc ensures 8-byte alignment. This is one plausible reason to
> keep the current int free list: an int object struct holds 3 4-byte
> members on most boxes (type pointer, refcount, and the int's value),
> and the int freelist code uses exactly 12 bytes for each on most
>
Neal Norwitz wrote:
> It's not just size. Architectures may require data aligned on 4, 8,
> or 16 addresses for optimal performance depending on data type. IIRC,
> malloc aligns by 8 (not sure if that was a particular arch or very
> common). I don't know if pymalloc handles alignment.
Yes, pyma
On Feb 6, 2008 4:46 AM, Facundo Batista <[EMAIL PROTECTED]> wrote:
> 2008/2/4, Brett Cannon <[EMAIL PROTECTED]>:
>
> > The 1 MB PDF can be found at
> > http://www.cs.ubc.ca/~drifty/pycon/sprint_tutorial.pdf . If you find
> > any bad info or some info that is really lacking, let me know. But
>
> Bre
On 2008-02-08 12:23, M.-A. Lemburg wrote:
> On 2008-02-08 08:21, Martin v. Löwis wrote:
>>> One of the hopes of having a custom allocator for Python was to be
>>> able to get rid off all free lists. For some reason that never happened.
>>> Not sure why. People were probably too busy with adding new
On 2008-02-08 19:28, Christian Heimes wrote:
>> In addition to the pure performance aspect, there is the issue of memory
>> utilisation. The current trunk code running the int test case in my
>> original post peaks at 151MB according to top on my FreeBSD box, dropping
>> back to about 62MB after t
On Feb 8, 2008 12:53 PM, Christian Heimes <[EMAIL PROTECTED]> wrote:
> Brett Cannon wrote:
> > The corrected version of the slides are now up at the same location.
>
> I found a minor mistake
>
> PC/
> * Build files for compilers older than VS 7.1.
>
> The PC directory contains build directories f
M.-A. Lemburg wrote:
> As you can see, Integers and floats fall into the same pymalloc size
> class. What's strange in Andrew's result is that both integers
> and floats use the same free list technique and fall into the same
> pymalloc size class, yet the results are different.
My take is not th
> Given the background information Python's long implementation could
> probably optimized. In 3.0 a long has 3 4-byte members (ref count,
> ob_size and *ob_type) plus one to many unsigned shorts (2 bytes each) to
> hold the value. If pymalloc aligns the objects at 8 byte address
> boundaries would
Tim Peters wrote:
> pymalloc ensures 8-byte alignment. This is one plausible reason to
> keep the current int free list: an int object struct holds 3 4-byte
> members on most boxes (type pointer, refcount, and the int's value),
> and the int freelist code uses exactly 12 bytes for each on most
>
Martin v. Löwis wrote:
> You mean, as the digits? You would have to rewrite the entire long
> datatype, which is a tedious exercise. Plus, I believe you would have
> to make some operations 64-bit on all systems: when you multiply
> digits today, the product will be 32-bit. If you extend the digits
ACTIVITY SUMMARY (02/01/08 - 02/08/08)
Tracker at http://bugs.python.org/
To view or respond to any of the issues listed below, click on the issue
number. Do NOT respond to this message.
1691 open (+30) / 12209 closed (+18) / 13900 total (+48)
Open issues with patches: 437
Average durati
[Neal Norwitz]
> It's not just size. Architectures may require data aligned on 4, 8,
> or 16 addresses for optimal performance depending on data type. IIRC,
> malloc aligns by 8 (not sure if that was a particular arch or very
> common).
Just very common. Because malloc has no idea what the poin
Christian Heimes wrote:
> Andrew MacIntyre wrote:
>> For the int case, that patch is slower than no free list at all. For the
>> float case its very slightly faster (55.3s vs 55.5s) than no free list at
>> all. Slower than the trunk code for both cases. Did you run the test
>> scripts on your ow
Brett Cannon wrote:
> The corrected version of the slides are now up at the same location.
I found a minor mistake
PC/
* Build files for compilers older than VS 7.1.
The PC directory contains build directories for VC6.0, VC 7.1, VC8.0 and
OS2.
Christian
19 matches
Mail list logo
