Remove hardware sampler support from oprofile module.
The oprofile user space utilty has been switched to use the kernel
perf interface, for which we also provide hardware sampling support.
In addition the hardware sampling support is also slightly broken: it
supports only 16 bits for the pid and therefore would generate wrong
results on machines which have a pid >64k.
Also the pt_regs structure which was passed to oprofile common code
cannot necessarily be used to generate sane backtraces, since the
task(s) in question may run while the samples are fed to oprofile.
So the result would be more or less random.
However given that the only user space tools switched to the perf
interface already four years ago the hardware sampler code seems to be
unused code, and therefore it should be reasonable to remove it.
The timer based oprofile support continues to work.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Andreas Arnez <arnez@linux.vnet.ibm.com>
Acked-by: Andreas Krebbel <krebbel@linux.vnet.ibm.com>
Acked-by: Robert Richter <rric@kernel.org>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We have four different stack tracers of which three had bugs. So it's
time to merge them to a single stack tracer which allows to specify a
call back function which will be called for each step.
This patch changes behavior a bit:
- the "nosched" and "in_sched_functions" check within
save_stack_trace_tsk did work only for the last stack frame within a
context. Now it considers the check for each stack frame like it
should.
- both the oprofile variant and the perf_events variant did save a
return address twice if a zero back chain was detected, which
indicates an interrupt frame. The new dump_trace function will call
the oprofile and perf_events backends with the psw address that is
contained within the corresponding pt_regs structure instead.
- the original show_trace and save_context_stack functions did already
use the psw address of the pt_regs structure if a zero back chain
was detected. However now we ignore the psw address if it is a user
space address. After all we trace the kernel stack and not the user
space stack. This way we also get rid of the garbage user space
address in case of warnings and / or panic call traces.
So this should make life easier since now there is only one stack
tracer left which we can break.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
git commit dc7ee00d47 ("s390: lowcore stack pointer offsets")
introduced a regression in regard to s390_backtrace(). The stack
pointer for the asynchronous stack in the lowcore now has an
additional offset applied. This offset needs to be taken into account
in the calculation for the low and high address for the stack.
This bug was already partially fixed with commit 9cc5c206d9
("s390/dumpstack: fix address ranges for asynchronous and panic
stack"). This patch fixes it also for the oprofile code.
Fixes: dc7ee00d47 ("s390: lowcore stack pointer offsets")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Yet another leftover from the 31 bit era. The usual operation
"y = x & PSW_ADDR_INSN" with the PSW_ADDR_INSN mask is a nop for
CONFIG_64BIT.
Therefore remove all usages and hope the code is a bit less confusing.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Fix these errors when compiling with CONFIG_OPROFILE=y and
CONFIG_PERF_EVENTS=n:
arch/s390/oprofile/init.c: In function ‘oprofile_hwsampler_start’:
arch/s390/oprofile/init.c:93:2: error: implicit declaration of function 'perf_reserve_sampling' [-Werror=implicit-function-declaration]
retval = perf_reserve_sampling();
^
arch/s390/oprofile/init.c:99:3: error: implicit declaration of function 'perf_release_sampling' [-Werror=implicit-function-declaration]
perf_release_sampling();
^
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.
The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e58 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.
Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
this_cpu_inc(y)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: linux390@de.ibm.com
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Delete unnecessary local variable whose value is always 0 and that hides
the fact that the result is always 0.
A simplified version of the semantic patch that fixes this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
local idexpression ret;
expression e;
position p;
@@
-ret = 0;
... when != ret = e
return
- ret
+ 0
;
// </smpl>
[heiko.carstens: turn prepare_cpu_buffers into a void returning function]
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the new defines for external interruption codes to get rid
of "magic" numbers in the s390 source code. And while we're at it,
also rename the (un-)register_external_interrupt function to
something shorter so that this patch does not exceed the 80
columns all over the place.
Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Also support the diagnostic-sampling function in addition to the basic-sampling
function. Diagnostic-sampling data entries contain hardware model specific
sampling data and additional programs are required to analyze the data.
To deliver diagnostic-sampling, as well, as basis-sampling data entries to user
space, introduce support for sampling "raw data". If this particular perf
sampling type (PERF_SAMPLE_RAW) is used, sampling data entries are copied
to user space. External programs can then analyze these data.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce reserve/release functions to share the sampling facility
between perf and oprofile.
Also improve error handling for the sampling facility support in perf.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Extract and move the oprofile hwsampler data structures and interfaces to
the cpu_mf.h header file which contains common interface definitions
for the various CPU-measurement facilities. This change is necessary for
a new perf PMU.
Few interface names have been revised to fit to the latest CPU-measurement
facilities documentation. Also declare the data structures as __packed and
correct checkpatch findings.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull more s390 updates from Heiko Carstens:
"This includes one bpf/jit bug fix where the jit compiler could
sometimes write generated code out of bounds of the allocated memory
area.
The rest of the patches are only cleanups and minor improvements"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/irq: reduce size of external interrupt handler hash array
s390/compat,uid16: use current_cred()
s390/ap_bus: use and-mask instead of a cast
s390/ftrace: avoid pointer arithmetics with function pointers
s390: make various functions static, add declarations to header files
s390/compat signal: add couple of __force annotations
s390/mm: add __releases()/__acquires() annotations to gmap_alloc_table()
s390: keep Kconfig sorted
s390/irq: rework irq subclass handling
s390/irq: use hlists for external interrupt handler array
s390/dumpstack: convert print_symbol to %pSR
s390/perf: Remove print_hex_dump_bytes() debug output
s390: update defconfig
s390/bpf,jit: fix address randomization
Let's not add a function for every external interrupt subclass for
which we need reference counting. Just have two register/unregister
functions which have a subclass parameter:
void irq_subclass_register(enum irq_subclass subclass);
void irq_subclass_unregister(enum irq_subclass subclass);
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
it's always equal to ->d_sb of the second argument (parent dentry),
due to either being literally that, or ->d_sb of parent's parent.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There is a misleading naming of the program parameter fields, so
correct them according to their names as outlined in
"The Load-Program-Parameter and the CPU-measurement Facilities"
(SA23-2260-03).
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds support for the latest release of the
IBM mainframe series - the IBM zEnterprise EC12 (zEC12).
The CPU measurement facility didn't change. So only the new CPU type
has to be tolerated.
Signed-off-by: Andreas Krebbel <krebbel@linux.vnet.ibm.com>
Signed-off-by: Robert Richter <rric@kernel.org>
Now that irq sum accounting for /proc/stat's "intr" line works again we
have the oddity that the sum field (first field) contains only the sum
of the second (external irqs) and third field (I/O interrupts).
The reason for that is that these two fields are already sums of all other
fields. So if we would sum up everything we would count every interrupt
twice.
This is broken since the split interrupt accounting was merged two years
ago: 052ff461c8 "[S390] irq: have detailed
statistics for interrupt types".
To fix this remove the split interrupt fields from /proc/stat's "intr"
line again and only have them in /proc/interrupts.
This restores the old behaviour, seems to be the only sane fix and mimics
a behaviour from other architectures where /proc/interrupts also contains
more than /proc/stat's "intr" line does.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If oprofilefs_ulong_from_user() is called with count equals zero, *val
remains unchanged. Depending on the implementation it might be
uninitialized. Fixing users of oprofilefs_ulong_ from_user().
We missed these s390 changes with:
913050b oprofile: Fix uninitialized memory access when writing to writing to oprofilefs
Cc: stable@vger.kernel.org # 3.3+
Signed-off-by: Robert Richter <robert.richter@amd.com>
We use the user_mode() helper already at several places but also
have the open coded variant at other places.
Convert the code to always use the helper function.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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>
Heiko Carstens
Sebastian Ott
Christoph Lameter
Julia Lawall
Thomas Huth
Hendrik Brueckner
Linus Torvalds
Al Viro
Andreas Krebbel
Robert Richter