Re: Re: Need help in creating 8GB RAMDISK

Re: Re: Need help in creating 8GB RAMDISK

[Fawad Lateef]

Dear Joel 

Can you please tell me the way of using more than 4GB
of RAM in a single process or module ???? I tried to
solve that problem using threads, but it isn't working
tooo, there might be the problem in my thread
implementation but can it be done using threads ???
Please do tell me way of doing this ......... 

I also tried to make 2 different modules each for 4GB
and then made another module which is just receiving
the request changes its bh->b_rdev to the
corresponding drive and returns 1. So kernel will try
to call the request function of the module related to
bh->b_rdev. but this is also not working .!!!!

Please help me ..... I m working on Linux-2.4.23

Thanks and Regards,

Fawad Lateef




> On Sun, 4 Jul 2004, Fawad Lateef wrote:
> 
> > Hello
> > 
> > I am creating a RAMDISK of 7GB (from 1GB to 8GB).
> I
> > reserved the RAM by changing the code in
> > arch/i386/mm/init.c .......... 
> > 
> > But I am not able to access the RAM from 1GB to
> 8GB in
> > a kernel module ........ after crossing the 4GB
> RAM,
> > the system goes into standby state. But if I
> insert
> > the same module 2 times means one for 1GB to 4GB
> and
> > other for 4GB to 8GB. and mount them seprately
> both
> > works fine ............ 
> 
> on a non-64bit intel architecture you can only grab
> 4GB of ram per 
> process because that's how big the page table is.
> There are 16 4GB page 
> tables for the 64GB ram that intel machines are
> capable of addressing.
>  
> > Can any one tell me the reason behind this ??? I
> think
> > that in a single module we can't access more than
> 4GB
> > RAM ...... If this is the reason then what to do
> ??? I
> > need 7GB RAMDISK as a single drive ....
> > 
> > Thanks and Regards,
> > 
> > Fawad Lateef
> > 
> > 
> > 		
> > __________________________________
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> > 
> 
> -- 
>
--------------------------------------------------------------------------
> 
> Joel Jaeggli  	       Unix Consulting 	      
> joelja@darkwing.uoregon.edu    
> GPG Key Fingerprint:     5C6E 0104 BAF0 40B0 5BD3
> C38B F000 35AB B67F 56B2
> 
> 
> -
> To unsubscribe from this list: send the line
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> 



		
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Re: Re: Need help in creating 8GB RAMDISK

[Joel Jaeggli]

sorry, butI don't think you're going to get there.  appending two 4GB 
rammdisks using linux software raidraid might work. but creating one 
single ramdisk larger won't work cleanly.


On Sun, 4 Jul 2004, Fawad Lateef wrote:

> Dear Joel 
> 
> Can you please tell me the way of using more than 4GB
> of RAM in a single process or module ???? I tried to
> solve that problem using threads, but it isn't working
> tooo, there might be the problem in my thread
> implementation but can it be done using threads ???
> Please do tell me way of doing this ......... 
> 
> I also tried to make 2 different modules each for 4GB
> and then made another module which is just receiving
> the request changes its bh->b_rdev to the
> corresponding drive and returns 1. So kernel will try
> to call the request function of the module related to
> bh->b_rdev. but this is also not working .!!!!
> 
> Please help me ..... I m working on Linux-2.4.23
> 
> Thanks and Regards,
> 
> Fawad Lateef
> 
> 
> 
> 
> > On Sun, 4 Jul 2004, Fawad Lateef wrote:
> > 
> > > Hello
> > > 
> > > I am creating a RAMDISK of 7GB (from 1GB to 8GB).
> > I
> > > reserved the RAM by changing the code in
> > > arch/i386/mm/init.c .......... 
> > > 
> > > But I am not able to access the RAM from 1GB to
> > 8GB in
> > > a kernel module ........ after crossing the 4GB
> > RAM,
> > > the system goes into standby state. But if I
> > insert
> > > the same module 2 times means one for 1GB to 4GB
> > and
> > > other for 4GB to 8GB. and mount them seprately
> > both
> > > works fine ............ 
> > 
> > on a non-64bit intel architecture you can only grab
> > 4GB of ram per 
> > process because that's how big the page table is.
> > There are 16 4GB page 
> > tables for the 64GB ram that intel machines are
> > capable of addressing.
> >  
> > > Can any one tell me the reason behind this ??? I
> > think
> > > that in a single module we can't access more than
> > 4GB
> > > RAM ...... If this is the reason then what to do
> > ??? I
> > > need 7GB RAMDISK as a single drive ....
> > > 
> > > Thanks and Regards,
> > > 
> > > Fawad Lateef
> > > 
> > > 
> > > 		
> > > __________________________________
> > > Do you Yahoo!?
> > > Yahoo! Mail - You care about security. So do we.
> > > http://promotions.yahoo.com/new_mail
> > > -
> > > To unsubscribe from this list: send the line
> > "unsubscribe linux-kernel" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at 
> > http://vger.kernel.org/majordomo-info.html
> > > Please read the FAQ at  http://www.tux.org/lkml/
> > > 
> > 
> > -- 
> >
> --------------------------------------------------------------------------
> > 
> > Joel Jaeggli  	       Unix Consulting 	      
> > joelja@darkwing.uoregon.edu    
> > GPG Key Fingerprint:     5C6E 0104 BAF0 40B0 5BD3
> > C38B F000 35AB B67F 56B2
> > 
> > 
> > -
> > To unsubscribe from this list: send the line
> > "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at 
> > http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at  http://www.tux.org/lkml/
> > 
> 
> 
> 
> 		
> __________________________________
> Do you Yahoo!?
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-- 
-------------------------------------------------------------------------- 
Joel Jaeggli  	       Unix Consulting 	       joelja@darkwing.uoregon.edu    
GPG Key Fingerprint:     5C6E 0104 BAF0 40B0 5BD3 C38B F000 35AB B67F 56B2

Re: Re: Need help in creating 8GB RAMDISK

[Fawad Lateef]

> ebiederm@xmission.com (Eric W. Biederman) writes:
> 
> What do you need this for?
> 
> Mostly it looks like you just need to use kmap,
> but...
> As other have pointed out ramfs is usually the
> better solution,
> and you don't need to code anything.
> 
> Or are you trying to use an 7GB initrd.  An
> interesting idea
> but that would take a little bootloader hacking to
> make work.

Actually I need 7GB RAMDISK to use with my Caching
Drive Project. I have to use RAMDISK of 7GB or more
for the Caching purpose. The Architecture is like Disk
Caching Disk (DCD), but here I hav to use RAMDISK. 

I created RAMDISK using physical address as I hav
reserved all RAM above 1GB for my RAMDISK, but I am
not able to create RAMDISK of 7GB as a single Drive. 

Is there any Idea regarding this ????

Fawad Lateef



		
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Re: Need help in creating 8GB RAMDISK

[John Richard Moser]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



Fawad Lateef wrote:
|>ebiederm@xmission.com (Eric W. Biederman) writes:

| Actually I need 7GB RAMDISK to use with my Caching
| Drive Project. I have to use RAMDISK of 7GB or more
| for the Caching purpose. The Architecture is like Disk
| Caching Disk (DCD), but here I hav to use RAMDISK.

What does this project do?

|
| I created RAMDISK using physical address as I hav
| reserved all RAM above 1GB for my RAMDISK, but I am
| not able to create RAMDISK of 7GB as a single Drive.
|
| Is there any Idea regarding this ????
|
| Fawad Lateef
|
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Re: Re: Need help in creating 8GB RAMDISK

[Fawad Lateef]

> John Richard Moser <nigelenki@comcast.net> wrote:
> 
> 
> Fawad Lateef wrote:
> 
> | Actually I need 7GB RAMDISK to use with my Caching
> | Drive Project. I have to use RAMDISK of 7GB or
> more
> | for the Caching purpose. The Architecture is like
> Disk
> | Caching Disk (DCD), but here I hav to use RAMDISK.
> 
> What does this project do?
> 
> |

This Project is Actually as I mentioned earlier is a
Caching Project and this will be the part of SAN
(Storage Area Network) Device. So, I m following the
Architecture smililar to Disk Caching Disk, in which 1
Disk is used for caching of data for many larger
disks. But here in my case I m using RAMDISK other
than the caching disk.

Fawad Lateef


	
		
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