Storing specified variables in the same memory page!

Storing specified variables in the same memory page!

[Vinay]

Hi,

I would like to know if there is any way by which I
can inform the compiler to store certain  variables in
the same memory page. This would really help my
project. If not possible, is there a way to change the
source code of GCC to implement the same.

Thanks,
Vinay

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Re: Storing specified variables in the same memory page!

[Sriharsha Vedurmudi]

Will global/static variables not be stored stored consistantly in one page?

-Harsha

Vinay wrote:

>Hi,
>
>I would like to know if there is any way by which I
>can inform the compiler to store certain  variables in
>the same memory page. This would really help my
>project. If not possible, is there a way to change the
>source code of GCC to implement the same.
>
>Thanks,
>Vinay
>
>________________________________________________________________________
>Yahoo! India Matrimony: Find your life partner online
>Go to: http://yahoo.shaadi.com/india-matrimony
>  
>

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 * Software Engineer		
 * 
 * Redpine Signals Inc.	
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 * www.redpinesignals.com	
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Re: Storing specified variables in the same memory page!

[Vinay]

Hi Harsha,

But the variables I would like to specify can be local
also. I need a way by which I can specify any type of
variable and they must be stored in the same memory
page.

Thanks,
Vinay
 --- Sriharsha Vedurmudi
<sriharsha.v@redpinesignals.com> wrote: 
> Will global/static variables not be stored stored
> consistantly in one page?
> 
> -Harsha
> 
> Vinay wrote:
> 
> >Hi,
> >
> >I would like to know if there is any way by which I
> >can inform the compiler to store certain  variables
> in
> >the same memory page. This would really help my
> >project. If not possible, is there a way to change
> the
> >source code of GCC to implement the same.
> >
> >Thanks,
> >Vinay
> >
>
>________________________________________________________________________
> >Yahoo! India Matrimony: Find your life partner
> online
> >Go to: http://yahoo.shaadi.com/india-matrimony
> >  
> >
> 
> -- 
>  *****************************
>  * Sriharsha Vedurmudi			
>  * Software Engineer		
>  * 
>  * Redpine Signals Inc.	
>  * Gate #395, Plot 87,88			
>  * Sagar Society, Road #2, 
>  * Banjara Hills,		
>  * Hyderabad - 500 034			
>  * www.redpinesignals.com	
>  *							
>  * +91-40-23559911  (Office)
>  * +91-9849133133   (Mobile)
>  *****************************
> 
>  

________________________________________________________________________
Yahoo! India Matrimony: Find your life partner online
Go to: http://yahoo.shaadi.com/india-matrimony

Re: Storing specified variables in the same memory page!

[energon]

Well, you can define a struct with the necessary variable types and
allocate some shared memory and map the struct into the shared memory.

Typically, shared memory is allocated in size of page size chunks.
So, if your data set size does not span the memory page size, you'll
have your data in one page.

Do you need to avoid your data from being paged out of the RAM?


=====
-energon0


		
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Re: (Question reframed)Storing specified variables in the same memory page!

[Vinay]

Hello all,

Thank you very much for all your replies. But the
project requirements are different. The problem is as
follows.

A main program shall be running. An user source
program is given as input to the main program. Along
with the source program, some variables present in the
source program shall also be specified. From the main
program, I need to inform the compiler to allocate
successive memory locations for these variables so
that they reside on the same memory page. 

The main program is not allowed to change the type of
the variables.

Please give suggestions.

Thanks,
Vinay
--- energon <energon0@yahoo.com> wrote: 
> 
> Well, you can define a struct with the necessary
> variable types and
> allocate some shared memory and map the struct into
> the shared memory.
> 
> Typically, shared memory is allocated in size of
> page size chunks.
> So, if your data set size does not span the memory
> page size, you'll
> have your data in one page.
> 
> Do you need to avoid your data from being paged out
> of the RAM?
> 
> 
> =====
> -energon0
> 
> 
> 		
> _______________________________
> Do you Yahoo!?
> Declare Yourself - Register online to vote today!
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>  

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Re: (Question reframed)Storing specified variables in the same memory page!

[Eljay Love-Jensen]

Hi Vinay,

Before worrying about this memory optimization, first get the program to 
work the normal way.

Then, after the program is working, try to optimize the variable placement 
by allocating a chunk of memory.  Put the variables in that allocated 
memory chunk.

HTH,
--Eljay

Re: (Question reframed)Storing specified variables in the same memory page!

[Sriharsha Vedurmudi]

Hi Vinay,
    is your aim something like an intelligent program editor where-in 
you write a program and execute the 'compile' option in the editor. Here 
the editor picks up the source program and passes it on to the compiler 
for compilation. The extra functionality you need is that some of the 
variables that are explicitly specified should be allocated in 
contiguous/successive memory locations? Is it?

    Well, I am not aware of any such options for gcc atleast, but I feel 
that such things are to be taken care in the source program itself. 
Encapsulate them in a structure, as suggested earlier.

    Still I wonder why you would want them on a same memory page? Is it 
purely for speed optimization?

Regards,
Harsha.

Vinay wrote:

>Hello all,
>
>Thank you very much for all your replies. But the
>project requirements are different. The problem is as
>follows.
>
>A main program shall be running. An user source
>program is given as input to the main program. Along
>with the source program, some variables present in the
>source program shall also be specified. From the main
>program, I need to inform the compiler to allocate
>successive memory locations for these variables so
>that they reside on the same memory page. 
>
>The main program is not allowed to change the type of
>the variables.
>
>Please give suggestions.
>
>Thanks,
>Vinay
>--- energon <energon0@yahoo.com> wrote: 
>  
>
>>Well, you can define a struct with the necessary
>>variable types and
>>allocate some shared memory and map the struct into
>>the shared memory.
>>
>>Typically, shared memory is allocated in size of
>>page size chunks.
>>So, if your data set size does not span the memory
>>page size, you'll
>>have your data in one page.
>>
>>Do you need to avoid your data from being paged out
>>of the RAM?
>>
>>
>>=====
>>-energon0
>>
>>
>>		
>>_______________________________
>>Do you Yahoo!?
>>Declare Yourself - Register online to vote today!
>>http://vote.yahoo.com
>> 
>>    
>>
>
>________________________________________________________________________
>Yahoo! India Matrimony: Find your life partner online
>Go to: http://yahoo.shaadi.com/india-matrimony
>  
>

-- 
 *****************************
 * Sriharsha Vedurmudi			
 * Software Engineer		
 * 
 * Redpine Signals Inc.	
 * Gate #395, Plot 87,88			
 * Sagar Society, Road #2, 
 * Banjara Hills,		
 * Hyderabad - 500 034			
 * www.redpinesignals.com	
 *							
 * +91-40-23559911  (Office)
 * +91-9849133133   (Mobile)
 *****************************

Re: (Question reframed)Storing specified variables in the same memory page!

[energon]

1. or maybe, tag your variables with a specific tag,

2. a. then write a filter program to generate code with
      a struct getting populated with the specially tagged
      variables as members
   b. then map accesses to the tagged  variables as members
      of the struct
   c. the memory for the struct could be on the stack or the
      heap, and the code generated appropriately

3. then pass this generated code to the actual GCC


=====
-energon0


		
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