topic Re: sbrk value in Operating System - HP-UX

sbrk value

Yajuvendra Singh — Mon, 20 Feb 2006 11:56:18 GMT

Dear All,

I want to know what is the meaning of term "sbrk" value.

I am not able to use my CAD softwares as I am getting error like:

current sbrk value = 0x15A4E000
Maximum sbrk value = 0x7A000000

b) How to increase the swap space in unix.

Thanks in advance.

Regards,
Yajuvendra Singh

Re: sbrk value

Steven E. Protter — Mon, 20 Feb 2006 12:03:48 GMT

Shalom

kmtune | grep 0x15A4E000

That might help you find out what kernel parameter to adjust.

Always state your system type and OS version when asking for help, so it can b e more detailed.

SEP

Re: sbrk value

Yajuvendra Singh — Mon, 20 Feb 2006 12:07:54 GMT

Dear Steven,

Thanks for your instant reply. I am having c8000 machine loaded with HP-UX 11.11i.

Regards,
Yajuvendra Singh

Re: sbrk value

A. Clay Stephenson — Mon, 20 Feb 2006 12:15:55 GMT

sbrk() is the system call that underlies the higher-level process dynamic memory allocation functions such as malloc(), calloc(), and realloc(). You need to increase maxdsiz or if this is a 64-bit process then you need to increase maxdsiz_64bit. In 32-bit land, both the stack and the heap share the same 1GB quadrant, so often the problem is that maxssiz has been increased too much and that has the unintended effect of limiting dynamic memory allocation. Set maxssiz and no more than 64MB (and that is very generous; 32MB is typically more appropriate). 64MB is even a generous value for massiz_64bit because well-written software does not require huge stacks.

Re: sbrk value

Yajuvendra Singh — Mon, 20 Mar 2006 13:55:30 GMT

Thank you all.