Based on an original patch by Valentine Barshak <vbarshak@ru.mvista.com> Use preempt_schedule_irq to prevent infinite irq-entry and eventual stack overflow problems with fast-paced IRQ sources. This kind of problems has been observed on the PASemi Electra IDE controller. We have to make sure we are soft-disabled before calling preempt_schedule_irq and hard disable interrupts after that to avoid unrecoverable exceptions. This patch also moves the "clrrdi r9,r1,THREAD_SHIFT" out of the #ifdef CONFIG_PPC_BOOK3E scope, since r9 is clobbered and has to be restored in both cases. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The mod_return_to_handler needs to switch to the kernel TOC before jumping to a the kernel code. It currently does this by looking at the kernel function data and retrieves the TOC that way. Not only is this inefficient, it also breaks with a relocatable kernel. The PACA contains the kernel TOC and we can easily retrieve it that way. Reported-by: Sachin Sant <sachinp@in.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Bye-bye Performance Counters, welcome Performance Events!
In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.
Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.
All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)
The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.
Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.
User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)
This patch has been generated via the following script:
FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')
sed -i \
-e 's/PERF_EVENT_/PERF_RECORD_/g' \
-e 's/PERF_COUNTER/PERF_EVENT/g' \
-e 's/perf_counter/perf_event/g' \
-e 's/nb_counters/nb_events/g' \
-e 's/swcounter/swevent/g' \
-e 's/tpcounter_event/tp_event/g' \
$FILES
for N in $(find . -name perf_counter.[ch]); do
M=$(echo $N | sed 's/perf_counter/perf_event/g')
mv $N $M
done
FILES=$(find . -name perf_event.*)
sed -i \
-e 's/COUNTER_MASK/REG_MASK/g' \
-e 's/COUNTER/EVENT/g' \
-e 's/\<event\>/event_id/g' \
-e 's/counter/event/g' \
-e 's/Counter/Event/g' \
$FILES
... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.
Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.
( NOTE: 'counters' are still the proper terminology when we deal
with hardware registers - and these sed scripts are a bit
over-eager in renaming them. I've undone some of that, but
in case there's something left where 'counter' would be
better than 'event' we can undo that on an individual basis
instead of touching an otherwise nicely automated patch. )
Suggested-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This contains all the bits that didn't fit in previous patches :-) This includes the actual exception handlers assembly, the changes to the kernel entry, other misc bits and wiring it all up in Kconfig. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
enter_prom() used to save and restore registers such as CTR, XER etc.. which are volatile, or SRR0,1... which we don't care about. This removes a bunch of useless code and while at it turns an mtmsrd into an MTMSRD macro which will be useful to Book3E. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The kernel uses SPRG registers for various purposes, typically in low level assembly code as scratch registers or to hold per-cpu global infos such as the PACA or the current thread_info pointer. We want to be able to easily shuffle the usage of those registers as some implementations have specific constraints realted to some of them, for example, some have userspace readable aliases, etc.. and the current choice isn't always the best. This patch should not change any code generation, and replaces the usage of SPRN_SPRGn everywhere in the kernel with a named replacement and adds documentation next to the definition of the names as to what those are used for on each processor family. The only parts that still use the original numbers are bits of KVM or suspend/resume code that just blindly needs to save/restore all the SPRGs. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Merge reason: we have gathered quite a few conflicts, need to merge upstream Conflicts: arch/powerpc/kernel/Makefile arch/x86/ia32/ia32entry.S arch/x86/include/asm/hardirq.h arch/x86/include/asm/unistd_32.h arch/x86/include/asm/unistd_64.h arch/x86/kernel/cpu/common.c arch/x86/kernel/irq.c arch/x86/kernel/syscall_table_32.S arch/x86/mm/iomap_32.c include/linux/sched.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
The TOCS used by modules are different than the one used by the core kernel code. The function graph tracer must save and restore the TOC whenever it traces a module call. But this is an added overhead to burden the majority of core kernel code being traced. Benjamin Herrenschmidt suggested in testing the entry of the call to tell if it is a core kernel function or a module. He recommended using the REGION_ID() macro to perform this test. This patch implements Benjamin's idea, and uses a different return_to_handler routine dependent on if the entry is a core kernel function or not. The module version saves the TOC, where as the core kernel version does not. Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is the port of the function graph tracer to PowerPC with dynamic tracing. Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is a port of the function graph tracer that was written by
Frederic Weisbecker for the x86.
This only works for PPC64 at the moment and only for static tracing.
PPC32 and dynamic function graph tracing support will come later.
The trace produces a visual calling of functions:
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
0) 2.224 us | }
0) ! 271.024 us | }
0) ! 320.080 us | }
0) ! 324.656 us | }
0) ! 329.136 us | }
0) | .put_prev_task_fair() {
0) | .update_curr() {
0) 2.240 us | .update_min_vruntime();
0) 6.512 us | }
0) 2.528 us | .__enqueue_entity();
0) + 15.536 us | }
0) | .pick_next_task_fair() {
0) 2.032 us | .__pick_next_entity();
0) 2.064 us | .__clear_buddies();
0) | .set_next_entity() {
0) 2.672 us | .__dequeue_entity();
0) 6.864 us | }
Geoff Lavand tested on PS3.
Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>