lkml.org 
[lkml]   [2005]   [May]   [10]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
DateTue, 10 May 2005 00:13:27 -0700
FromPaul Jackson <>
SubjectRe: /proc/cpuinfo format - arch dependent!
Jim wrote:
> I see two problems with encouraging applications to get involved
> with processor selection.

I suspect you are confusing "application" with "not kernel".

There are basically three layers of software on big systems:

 1) kernel
 2) administration (system services, libraries and utilities)
 3) application

Something like a batch manager is an example in layer (2) that needs
extensive knowledge of a systems hardware, and extensive ability to
manage exactly what runs and allocates where.

Large systems very much expect to manage what threads run where. These
API's are already present - check out sched_setaffinity, mbind,
set_mempolicy, and cpusets.  The details of what hardware is where,
including memory, processor and interconnect, are also there as well, in
various /proc and /sys files.

No - we don't expect the application to know all this.  But we absolutely
require that various admin level programs know this stuff in intimate
detail, and enable the administration of large systems in a variety of
ways.

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@engr.sgi.com> 1.650.933.1373, 1.925.600.0401
-
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/

\
 
 \ /
  Last update: 2005-05-10 09:17    [from the cache]
©2003-2008