Problem with #garbageCollect and -memory parameter

Hi,

I'm away and cannot check this right now, but if you look in the
SqS/VMMaker archive there there are a number of recent updates that
may address this problem. See the Montecello update comments for
VMMaker-dtl.188, VMMaker-dtl.199, and VMMaker-dtl.200 for summaries.
These updates would not be in any of the released VMs at this point,
but I have a hunch that they will take care of this problem.

Dave

On Tue, Nov 30, 2010 at 02:43:50PM +0100, Mariano Martinez Peck wrote:
>
> Hi folks. I am using the standard SqueakVM  4.2.5beta1U.
> If I run normaly the VM with a normal Pharo image and I print Smalltalk
> garbageCollect -> I get something like  492130460
>
> Now...if I run the vm with the parameter -memory 1500m  and I then print
> Smalltalk garbageCollect -> I get a NEGATIVE number like:  -619402660
>
> I guess there is a problem in somewhere like ObjectMemory >> bytesLeft:
> but I don't know...
>
> Anyway, the problem in my case is in SmalltalkImage:
>
> okayToProceedEvenIfSpaceIsLow
>     "Return true if either there is enough memory to do so safely or if the
> user gives permission after being given fair warning."
>
>     self garbageCollectMost > self lowSpaceThreshold ifTrue: [^ true].
> "quick"
>     self garbageCollect > self lowSpaceThreshold ifTrue: [^ true].  "work
> harder"
>
>     ^ self confirm:
> 'WARNING: There is not enough space to start the low space watcher.
> If you proceed, you will not be warned again, and the system may
> run out of memory and crash. If you do proceed, you can start the
> low space notifier when more space becomes available simply by
> opening and then closing a debugger (e.g., by hitting Cmd-period.)
> Do you want to proceed?'
>
>
> Since both of the first answers false because, of course garbageCollectMost
> and garbageCollect are negative....
> then I have that poup all the time.
>
> To fix this I have to posibilities:
>
> 1) Just patch this particular method to:
>
> self garbageCollectMost.
> self primBytesLeft > self lowSpaceThreshold ifTrue: [^ true].  "quick"
> self garbageCollect
> self primBytesLeft > self lowSpaceThreshold ifTrue: [^ true].  "work harder"
>
> Notice that primBytesLeft is answering correct. Wait..I don't know if
> correct, but at least possitive:  5691396
> I think this is possitive because the primitive is not receiving a
> parameter, and thus, Interpreter >> primitiveBytesLeft
> evaluates the first part of the method, which just does self sizeOfFree:
> freeBlock , and not the second part where it does self bytesLeft: aBool.
>
> 2) understand why it is negative and fix it from the VM side (I have no idea
> how to do this).
>
> Now, in addition, I wonder if there may be other places broken because of
> this....I am having some crashed and I don't know why :(
>
> Thanks in advance,
>
> Mariano

On Tue, Nov 30, 2010 at 5:14 PM, David T. Lewis <[hidden email]> wrote:

Hi,

I'm away and cannot check this right now, but if you look in the
SqS/VMMaker archive there there are a number of recent updates that
may address this problem. See the Montecello update comments for
VMMaker-dtl.188, VMMaker-dtl.199, and VMMaker-dtl.200 for summaries.
These updates would not be in any of the released VMs at this point,
but I have a hunch that they will take care of this problem.

Hi Dave. Ok...after a couple of hours I could compile a new VM for MacOS with VMMaker 205 and integrating all my changes :)
So....this was something I have to do since several months already hehhehe

Now, as you guessed, something  was related to that. Now, these are the results:

normal:

Smalltalk garbageCollect   481957728
Smalltalk primBytesLeft 5738200

with -memory 1500m

Smalltalk garbageCollect    482093452
Smalltalk primBytesLeft 6444200

 

Now, at least it is not negative. But I wonder....shouldn't I have more bytes left when I send 1500m ?
how can I be sure that the VM is actually tacking into account this parameter?
can I check some parameter in Smalltalk vmParameterAt:
?

thanks!

mariano

Dave

On Tue, Nov 30, 2010 at 02:43:50PM +0100, Mariano Martinez Peck wrote:
>
> Hi folks. I am using the standard SqueakVM  4.2.5beta1U.
> If I run normaly the VM with a normal Pharo image and I print Smalltalk
> garbageCollect -> I get something like  492130460
>
> Now...if I run the vm with the parameter -memory 1500m  and I then print
> Smalltalk garbageCollect -> I get a NEGATIVE number like:  -619402660
>
> I guess there is a problem in somewhere like ObjectMemory >> bytesLeft:
> but I don't know...
>
> Anyway, the problem in my case is in SmalltalkImage:
>
> okayToProceedEvenIfSpaceIsLow
>     "Return true if either there is enough memory to do so safely or if the
> user gives permission after being given fair warning."
>
>     self garbageCollectMost > self lowSpaceThreshold ifTrue: [^ true].
> "quick"
>     self garbageCollect > self lowSpaceThreshold ifTrue: [^ true].  "work
> harder"
>
>     ^ self confirm:
> 'WARNING: There is not enough space to start the low space watcher.
> If you proceed, you will not be warned again, and the system may
> run out of memory and crash. If you do proceed, you can start the
> low space notifier when more space becomes available simply by
> opening and then closing a debugger (e.g., by hitting Cmd-period.)
> Do you want to proceed?'
>
>
> Since both of the first answers false because, of course garbageCollectMost
> and garbageCollect are negative....
> then I have that poup all the time.
>
> To fix this I have to posibilities:
>
> 1) Just patch this particular method to:
>
> self garbageCollectMost.
> self primBytesLeft > self lowSpaceThreshold ifTrue: [^ true].  "quick"
> self garbageCollect
> self primBytesLeft > self lowSpaceThreshold ifTrue: [^ true].  "work harder"
>
> Notice that primBytesLeft is answering correct. Wait..I don't know if
> correct, but at least possitive:  5691396
> I think this is possitive because the primitive is not receiving a
> parameter, and thus, Interpreter >> primitiveBytesLeft
> evaluates the first part of the method, which just does self sizeOfFree:
> freeBlock , and not the second part where it does self bytesLeft: aBool.
>
> 2) understand why it is negative and fix it from the VM side (I have no idea
> how to do this).
>
> Now, in addition, I wonder if there may be other places broken because of
> this....I am having some crashed and I don't know why :(
>
> Thanks in advance,
>
> Mariano

If you are compiling your own macintosh VM

then go look at
sqSqueakOSXApplication.m

- (NSInteger) parseArgument: (NSString *) argData peek: (NSString *) peek {
...
       if ([argData compare: @"-memory"] == NSOrderedSame) {
               gMaxHeapSize = (usqInt) [self strtobkm: [peek UTF8String]];
               return 2;
       }
       return 0;
}

and follow the bouncing gMaxHeapSize to see what happens.
You'll find the use at
        startOfmmapForANONMemory = mmap(startOfAnonymousMemory, freeSpaceRoundedUpToPageSize, PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED,0,(off_t)0);

in sqMacV2Memory.c

On 2010-11-30, at 5:03 PM, David T. Lewis wrote:

>
> On Wed, Dec 01, 2010 at 12:41:44AM +0100, Mariano Martinez Peck wrote:
>>
>> On Wed, Dec 1, 2010 at 12:11 AM, Mariano Martinez Peck <
>> [hidden email]> wrote:
>>>
>>> On Tue, Nov 30, 2010 at 5:14 PM, David T. Lewis <[hidden email]>wrote:
>>>>
>>>> I'm away and cannot check this right now, but if you look in the
>>>> SqS/VMMaker archive there there are a number of recent updates that
>>>> may address this problem. See the Montecello update comments for
>>>> VMMaker-dtl.188, VMMaker-dtl.199, and VMMaker-dtl.200 for summaries.
>>>> These updates would not be in any of the released VMs at this point,
>>>> but I have a hunch that they will take care of this problem.
>>>>
>>>
>>> Hi Dave. Ok...after a couple of hours I could compile a new VM for MacOS
>>> with VMMaker 205 and integrating all my changes :)
>>> So....this was something I have to do since several months already hehhehe
>>>
>>> Now, as you guessed, something  was related to that. Now, these are the
>>> results:
>>>
>>> normal:
>>>
>>> Smalltalk garbageCollect   481957728
>>> Smalltalk primBytesLeft 5738200
>>>
>>> with -memory 1500m
>>>
>>> Smalltalk garbageCollect    482093452
>>> Smalltalk primBytesLeft 6444200
>>>
>>
>> mmmmmmm  if instead of sending -memory I modify Info.plist  and I set
>> 1572864000  (1500gb)
>> then I get
>>
>> Smalltalk garbageCollect  1518058920
>> Smalltalk primBytesLeft 5898636
>>
>> :)
>>
>> so maybe the mac vm is not taking into acount -memory but it does the file?
>
> Well that's as good a theory as anything I could have made up ;-)
>
> To be serious, the -memory parameter is part of the unix VM, and
> other platforms may do things differently. So yes, I think you
> have found the right explanation.
>
> Dave
>
>

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