Can I determine CPU cache sizes ?

[Dr. David Kirkby]

Is there a way to determine the size of the L1 data cache, L1
instruction cache and L2 cache in Solaris from a C system call - i.e.
I **don't** want to use a command at the shell prompt?

I know the Sun compiler uses this information to optimise the code,
but I don't know whether it uses a system call to get the information
or just has a huge lookup table, that knows about each CPU.


--
Dr. David Kirkby,
Senior Research Fellow,
Department of Medical Physics,
University College London,
11-20 Capper St, London, WC1E 6JA.
Tel: 020 7679 6408 Fax: 020 7679 6269
Internal telephone: ext 46408
e-mail [email]davek@medphys.ucl.ac.uk[/email]

[ultrasparc3@hotmail.com]

In <3F207848.F5AFFBA9@ntlworld.com> "Dr. David Kirkby" <drkirkby@ntlworld.com> writes:

>Is there a way to determine the size of the L1 data cache, L1
>instruction cache and L2 cache in Solaris from a C system call

>I know the Sun compiler uses this information to optimise the code,
>but I don't know whether it uses a system call to get the information
>or just has a huge lookup table, that knows about each CPU.

even if it did have a lookup table it would still require some
sort of system call to determine the cpu type to determine which
table entry to use.

find the information you want in the output of "prtpicl -v -c cpu"
then use the interfaces described in libpicl(3LIB) to do the same thing
in your own code.

[Dr. David Kirkby]

[email]ultrasparc3@hotmail.com[/email] wrote:

>
> In <3F207848.F5AFFBA9@ntlworld.com> "Dr. David Kirkby" <drkirkby@ntlworld.com> writes:

> >Is there a way to determine the size of the L1 data cache, L1
> >instruction cache and L2 cache in Solaris from a C system call

>

> >I know the Sun compiler uses this information to optimise the code,
> >but I don't know whether it uses a system call to get the information
> >or just has a huge lookup table, that knows about each CPU.

>

> even if it did have a lookup table it would still require some
> sort of system call to determine the cpu type to determine which
> table entry to use.

True, but one might image there being a call to get the cpu type, but
not the detailed information about the cpu.

> find the information you want in the output of "prtpicl -v -c cpu"
> then use the interfaces described in libpicl(3LIB) to do the same thing
> in your own code.

Thanks, that is useful.

--
Dr. David Kirkby,
Senior Research Fellow,
Department of Medical Physics,
University College London,
11-20 Capper St, London, WC1E 6JA.
Tel: 020 7679 6408 Fax: 020 7679 6269
Internal telephone: ext 46408
e-mail [email]davek@medphys.ucl.ac.uk[/email]