Commit Graph

5 Commits

Author SHA1 Message Date
Jason Yeh
4d4036e0e7 oprofile: Implement performance counter multiplexing
The number of hardware counters is limited. The multiplexing feature
enables OProfile to gather more events than counters are provided by
the hardware. This is realized by switching between events at an user
specified time interval.

A new file (/dev/oprofile/time_slice) is added for the user to specify
the timer interval in ms. If the number of events to profile is higher
than the number of hardware counters available, the patch will
schedule a work queue that switches the event counter and re-writes
the different sets of values into it. The switching mechanism needs to
be implemented for each architecture to support multiplexing. This
patch only implements AMD CPU support, but multiplexing can be easily
extended for other models and architectures.

There are follow-on patches that rework parts of this patch.

Signed-off-by: Jason Yeh <jason.yeh@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-07-20 16:33:53 +02:00
Robert Richter
0f019cc477 oprofile: fixing whitespaces in arch/x86/oprofile/*
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-16 17:17:46 +02:00
Robert Richter
4c168eaf7e Revert "Oprofile Multiplexing Patch"
Reverting commit 1a960b402a for the main
branch. Multiplexing will be tracked on a separate feature branch.

Conflicts:

    arch/x86/oprofile/nmi_int.c
2008-09-24 11:08:52 +02:00
Jason Yeh
1a960b402a Oprofile Multiplexing Patch
This patch introduces multiplexing support for the Oprofile kernel
module. It basically adds a new function pointer in oprofile_operator
allowing each architecture to supply its callback to switch between
different sets of event when the timer expires. Userspace tools can
modify the time slice through /dev/oprofile/time_slice.

It also modifies the number of counters exposed to the userspace through
/dev/oprofile. For example, the number of counters for AMD CPUs are
changed to 32 and multiplexed in the sets of 4.

Signed-off-by: Jason Yeh <jason.yeh@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26 11:48:16 +02:00
Thomas Gleixner
ff4395654d i386: move oprofile
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 11:16:55 +02:00