The sampling interval for the hardware sampler is specified in cycles.
(see SA23-2260-01 The Load-Program-Parameter and the CPU-Measurement
Facilities)
The current default value will therefore result in millions of samples.
This patch changes the default sampling interval to 4M, which will
result in ~1500 samples per second on a z196 reducing the overhead
of sampling.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
On specific configurations with hwsampler opcontrol --start returns an
error on "echo 1 >/dev/oprofile/enable". Turns out that the hw sampling
interval is not checked against the hardware limits.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The hardware sample cpu hotplug notifier always returns NOTIFY_BAD.
That will prevent cpu hotplug if the machine is enabled for hardware
sampling even if it is not used. Fix the cpu hotplug notifier and
allow cpu hotplug if hardware sampling is unused.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Merge irq.c and s390_ext.c into irq.c. That way all external interrupt
related functions are together.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The external interrupt parameter is passed as function call parameter.
No need to access lowcore.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Use ctl_set_bit instead of the smp_ctl_set_bit (likewise for clear bit)
to prevent the following build error for !CONFIG_SMP:
CC arch/s390/oprofile/hwsampler.o
arch/s390/oprofile/hwsampler.c: In function ‘hwsampler_deallocate’:
arch/s390/oprofile/hwsampler.c:1012: error: implicit declaration of function ‘smp_ctl_clear_bit’
arch/s390/oprofile/hwsampler.c: In function ‘hwsampler_start_all’:
arch/s390/oprofile/hwsampler.c:1201: error: implicit declaration of function ‘smp_ctl_set_bit’
CC kernel/seccomp.o
make[1]: *** [arch/s390/oprofile/hwsampler.o] Error 1
make: *** [arch/s390/oprofile] Error 2
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The counter for requested interrupts should be incremented if the
program-request-alert bit is set and not the invalid-address-entry
bit.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
oprofile_min_interval and oprofile_max_interval are unsigned, checking
for negative values doesn't work. Change hwsampler_query_min_interval
and hwsampler_query_max_interval to return an unsigned long and
check for a zero value instead.
Reported-by: Nicolas Kaiser <nikai@nikai.net>
Acked-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Prevent stack corruption by memcpy which copies more bytes then
available at the destination. While at it use the new test_facility
to test for the facility bit.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Doesn't work and build for CONFIG_32BIT. So disable it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove unused HAVE_HWSAMPLER config option. It is not used anymore,
removing it.
Also make some functions static and some coding style fixes.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Merge the contents of hwsampler_files.c into
arch/s390/oprofile/init.c.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Fixes the following section mismatch:
Section mismatch in reference from the variable hws_cpu_notifier to the function .cpuinit.text:hws_cpu_callback()
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch is a rework of the hwsampler oprofile implementation that
has been applied recently. Now there are less non-architectural
changes. The only changes are:
* introduction of oprofile_add_ext_hw_sample(), and
* removal of section attributes of oprofile_timer_init/_exit().
To setup hwsampler for oprofile we need to modify start()/stop()
callbacks and additional hwsampler control files in oprofilefs. We do
not reinitialize the timer or hwsampler mode by restarting calling
init/exit() anymore, instead hwsampler_running is used to switch the
mode directly in oprofile_hwsampler_start/_stop(). For locking reasons
there is also hwsampler_file that reflects the value in oprofilefs.
The overall diffstat of the oprofile s390 hwsampler implemenation
shows the low impact to non-architectural code:
arch/Kconfig | 3 +
arch/s390/Kconfig | 1 +
arch/s390/oprofile/Makefile | 2 +-
arch/s390/oprofile/hwsampler.c | 1256 ++++++++++++++++++++++++++++++++++
arch/s390/oprofile/hwsampler.h | 113 +++
arch/s390/oprofile/hwsampler_files.c | 162 +++++
arch/s390/oprofile/init.c | 6 +-
drivers/oprofile/cpu_buffer.c | 24 +-
drivers/oprofile/timer_int.c | 4 +-
include/linux/oprofile.h | 7 +
10 files changed, 1567 insertions(+), 11 deletions(-)
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
OProfile is enhanced to export all files for controlling System z's
hardware sampling, and to invoke hwsampler exported functions to
initialize and use System z's hardware sampling.
The patch invokes hwsampler_setup() during oprofile init and exports
following hwsampler files under oprofilefs if hwsampler's setup
succeeded:
A new directory for hardware sampling based files
/dev/oprofile/hwsampling/
The userland daemon must explicitly write to the following files
to disable (or enable) hardware based sampling
/dev/oprofile/hwsampling/hwsampler
to modify the actual sampling rate
/dev/oprofile/hwsampling/hw_interval
to modify the amount of sampling memory (measured in 4K pages)
/dev/oprofile/hwsampling/hw_sdbt_blocks
The following files are read only and show
the possible minimum sampling rate
/dev/oprofile/hwsampling/hw_min_interval
the possible maximum sampling rate
/dev/oprofile/hwsampling/hw_max_interval
The patch splits the oprofile_timer_[init/exit] function so that it
can be also called through user context (oprofilefs) to avoid kernel
oops.
Applied with following changes:
* whitespace changes in Makefile and timer_int.c
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Maran Pakkirisamy <maranp@linux.vnet.ibm.com>
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This adds support for hardware based sampling on System z processors
(models z10 and up).
System z's hardware sampling is described in detail in:
SA23-2260-01 "The Load-Program-Parameter and CPU-Measurement Facilities"
The patch introduces
- support for System z's hardware sampler in OProfile's kernel module
- it adds functions that control all hardware sampling related
operations as:
- checking if hardware sampling feature is available, i.e.: on
System z models z10 and up, in LPAR mode only, and authorised
during LPAR activation
- allocating memory for the hardware sampling feature
- starting/stopping hardware sampling
All functions required to start and stop hardware sampling have to be
invoked by the oprofile kernel module as provided by the other patches
of this patch set.
In case hardware based sampling cannot be setup standard timer based
sampling is used by OProfile.
Applied with following changes:
* enable compilation in Makefile
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Maran Pakkirisamy <maranp@linux.vnet.ibm.com>
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Quoting Randy:
"It seems sad that this patch sources Kconfig.marker, a 7-line file,
20-something times. Yes, you (we) don't want to put those 7 lines into
20-something different files, so sourcing is the right thing.
However, what you did for avr32 seems more on the right track to me: make
_one_ Instrumentation support menu that includes PROFILING, OPROFILE, KPROBES,
and MARKERS and then use (source) that in all of the arches."
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
