Skip to contentSkip to conversation

Need help in creating 8GB RAMDISK

DISCUSSION Fawad Lateef 2 participants 2 messages Jul 5, 2004

lore
Share & tools
lore
#0 lore raw

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

Quoted 48 lines · Fawad Lateef
Quoted 4 lines

Hello

I am creating a RAMDISK of 7GB (from 1GB to 8GB).

I

Quoted 4 lines

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

Quoted 1 line

a kernel module ........ after crossing the 4GB

RAM,

Quoted 1 line

the system goes into standby state. But if I

insert

Quoted 1 line

the same module 2 times means one for 1GB to 4GB

and

Quoted 1 line

other for 4GB to 8GB. and mount them seprately

both

Quoted 1 line

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.

Quoted 1 line

Can any one tell me the reason behind this ??? I

think

Quoted 1 line

that in a single module we can't access more than

4GB

Quoted 1 line

RAM ...... If this is the reason then what to do

??? I

Quoted 8 lines

need 7GB RAMDISK as a single drive ....

Thanks and Regards,

Fawad Lateef

Quoted 6 lines

__________________________________
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

Quoted 9 lines

"unsubscribe linux-kernel" in

Quoted 2 lines

the body of a message to [email protected] More majordomo info at

http://vger.kernel.org/majordomo-info.html

Quoted 2 lines

Please read the FAQ at http://www.tux.org/lkml/

--------------------------------------------------------------------------

Quoted 7 lines

Joel Jaeggli Unix Consulting
[email protected]
GPG Key Fingerprint: 5C6E 0104 BAF0 40B0 5BD3
C38B F000 35AB B67F 56B2

Quoted 8 lines

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected] More majordomo info at
http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

__________________________________
Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!
http://promotions.yahoo.com/new_mail

#1 lore raw

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.

Quoted 107 lines · 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

Quoted 48 lines · Fawad Lateef
Quoted 4 lines

Hello

I am creating a RAMDISK of 7GB (from 1GB to 8GB).

I

Quoted 4 lines

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

Quoted 1 line

a kernel module ........ after crossing the 4GB

RAM,

Quoted 1 line

the system goes into standby state. But if I

insert

Quoted 1 line

the same module 2 times means one for 1GB to 4GB

and

Quoted 1 line

other for 4GB to 8GB. and mount them seprately

both

Quoted 1 line

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.

Quoted 1 line

Can any one tell me the reason behind this ??? I

think

Quoted 1 line

that in a single module we can't access more than

4GB

Quoted 1 line

RAM ...... If this is the reason then what to do

??? I

Quoted 8 lines

need 7GB RAMDISK as a single drive ....

Thanks and Regards,

Fawad Lateef

Quoted 6 lines

__________________________________
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

Quoted 9 lines

"unsubscribe linux-kernel" in

Quoted 2 lines

the body of a message to [email protected] More majordomo info at

http://vger.kernel.org/majordomo-info.html

Quoted 2 lines

Please read the FAQ at http://www.tux.org/lkml/

--------------------------------------------------------------------------

Quoted 7 lines

Joel Jaeggli Unix Consulting
[email protected]
GPG Key Fingerprint: 5C6E 0104 BAF0 40B0 5BD3
C38B F000 35AB B67F 56B2

Quoted 8 lines

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected] More majordomo info at
http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

__________________________________
Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!
http://promotions.yahoo.com/new_mail

Signature · 3 lines
-------------------------------------------------------------------------- 
Joel Jaeggli  	       Unix Consulting 	       [email protected]    
GPG Key Fingerprint:     5C6E 0104 BAF0 40B0 5BD3 C38B F000 35AB B67F 56B2