On Thu, Feb 19, 2009 at 1:56 AM, John Cremona <john.crem...@gmail.com> wrote:
>
>
>
>
>>
>>
>> > 3. A segfault on OS X 10.5 32-bit Intel (bsd.math.washington.edu):
>>
>> > sage -t -long "devel/sage/sage/schemes/elliptic_curves/ell_finite_field.py"
>> > A mysterious error (perphaps a memory error?) occurred, which may have
>> > crashed doctest.
>> > [22.7 s]
>>
>> > Doing this again with --verbose yields:
>>
>> > ----------------------------------------------
>> > Trying:
>> > for p in prime_range(Integer(10000)): #long time
>> > (~20s)###line 1206:_sage_ >>> for p in prime_range(10000):
>> > #long time (~20s)
>> > if p != Integer(389):
>> > G=E.change_ring(GF(p)).abelian_group()
>> > Expecting nothing
>>
>> > error: no more memory
>> > System 5120k:5120k Appl 4681k/438k Malloc 4095k/0k Valloc 1024k/438k
>> > Pages 161/95 Regions 2:2
>>
>> > halt 14
>> > [33.3 s]
>> > exit code: 1024
>> > ----------------------------------------------
>>
>> > Having this fail on a box with 8GB RAM is unacceptable (even if it is
>> > 32-bit).
>>
>> This has been #3760 for a while. IIRC that doctest passes with Sage
>> build in 64 bit mode on OSX, but it would not surprised me if this is
>> pari related.
>>
>
> Can William or someone who gets this error (I don't!) test what
> happens if you replace
>
> G=E.change_ring(GF(p)).abelian_group()
>
> by
>
> N=E.change_ring(GF(p)).cardinality()
Same problem:
Trying:
for p in prime_range(Integer(10000)): #long time
(~20s)###line 1206:_sage_ >>> for p in prime_range(10000):
#long time (~20s)
if p != Integer(389):
G=E.change_ring(GF(p)).cardinality()
Expecting nothing
error: no more memory
System 5116k:5116k Appl 4608k/507k Malloc 4087k/4k Valloc 1024k/503k
Pages 146/110 Regions 2:2
halt 14
[15.8 s]
exit code: 1024
In fact, even just change_ring and nothing else goes boom!
Trying:
for p in prime_range(Integer(10000)): #long time
(~20s)###line 1206:_sage_ >>> for p in prime_range(10000):
#long time (~20s)
if p != Integer(389):
G=E.change_ring(GF(p))
Expecting nothing
error: no more memory
System 5116k:5116k Appl 4608k/507k Malloc 4087k/4k Valloc 1024k/503k
Pages 146/110 Regions 2:2
teragon:sage-3.3.rc2 wstein$ sage
----------------------------------------------------------------------
| Sage Version 3.3.rc2, Release Date: 2009-02-17 |
| Type notebook() for the GUI, and license() for information. |
----------------------------------------------------------------------
sage: E = EllipticCurve('389a')
sage: time v = [E.change_ring(GF(p)) for p in prime_range(10000) if p != 389]
error: no more memory
System 5120k:5120k Appl 4638k/481k Malloc 4095k/0k Valloc 1024k/480k
Pages 153/103 Regions 2:2
halt 14
-------------
I believe that error is from *singular* -- it's not Python failing to
allocate. And that "error: no more memory" is a string in the
singular source code.
And this BS since it is not running out of memory:
sage: for p in prime_range(390,10000):
if p%13==1: print get_memory_usage()
v.append(E.change_ring(GF(p)))
...
139.0
139.0
139.0
140.0
141.0
141.0
141.0
error: no more memory
System 5120k:5120k Appl 4638k/481k Malloc 4095k/0k Valloc 1024k/480k
Pages 153/103 Regions 2:2
halt 14
teragon:sage-3.3.rc2 wstein$
OK, this is a singular problem for sure. Check this out:
teragon:sage-3.3.rc2 wstein$ sage
----------------------------------------------------------------------
| Sage Version 3.3.rc2, Release Date: 2009-02-17 |
| Type notebook() for the GUI, and license() for information. |
----------------------------------------------------------------------
sage: time v = [GF(p)['x,y'].gen() for p in prime_range(5000)]
error: no more memory
System 4608k:4608k Appl 4521k/86k Malloc 4093k/2k Valloc 512k/84k
Pages 124/4 Regions 1:1
halt 14
teragon:sage-3.3.rc2 wstein$
------------------------------------------------------
Anyway, John, you don't have to worry about this anymore, since it has
nothing to do with your code.
Martin Albrecht and the Singular team -- on the other hand...
William
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-devel@googlegroups.com
To unsubscribe from this group, send email to
sage-devel-unsubscr...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://www.sagemath.org
-~----------~----~----~----~------~----~------~--~---
