Commit Graph

2 Commits

Author SHA1 Message Date
Heiko Carstens
a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00
Andreas Krebbel
dd3c4670d7 oprofile, s390: Add event interface to the System z hardware sampling module
With this patch the OProfile Basic Mode Sampling support for System z
is enhanced with a counter file system.  That way hardware sampling
can be configured using the user space tools with only little
modifications.

With the patch by default new cpu_types (s390/z10, s390/z196) are
returned in order to indicate that we are running a CPU which provides
the hardware sampling facility.  Existing user space tools will
complain about an unknown cpu type. In order to be compatible with
existing user space tools the `cpu_type' module parameter has been
added.  Setting the parameter to `timer' will force the module to
return `timer' as cpu_type.  The module will still try to use hardware
sampling if available and the hwsampling virtual filesystem will be
also be available for configuration.  So this has a different effect
than using the generic oprofile module parameter `timer=1'.

If the basic mode sampling is enabled on the machine and the
cpu_type=timer parameter is not used the kernel module will provide
the following virtual filesystem:

/dev/oprofile/0/enabled
/dev/oprofile/0/event
/dev/oprofile/0/count
/dev/oprofile/0/unit_mask
/dev/oprofile/0/kernel
/dev/oprofile/0/user

In the counter file system only the values of 'enabled', 'count',
'kernel', and 'user' are evaluated by the kernel module. Everything
else must contain fixed values.

The 'event' value only supports a single event - HWSAMPLING with value
0.

The 'count' value specifies the hardware sampling rate as it is passed
to the CPU measurement facility.

The 'kernel' and 'user' flags can now be used to filter for samples
when using hardware sampling.

Additionally also the following file will be created:
/dev/oprofile/timer/enabled

This will always be the inverted value of /dev/oprofile/0/enabled. 0
is not accepted without hardware sampling.

Signed-off-by: Andreas Krebbel <krebbel@linux.vnet.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-12-07 11:47:09 +01:00