linux/kernel/events
Peter Zijlstra 5322ea58a0 perf/ring-buffer: Use regular variables for nesting
While the IRQ/NMI will nest, the nest-count will be invariant over the
actual exception, since it will decrement equal to increment.

This means we can -- carefully -- use a regular variable since the
typical LOAD-STORE race doesn't exist (similar to preempt_count).

This optimizes the ring-buffer for all LOAD-STORE architectures, since
they need to use atomic ops to implement local_t.

Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: mark.rutland@arm.com
Cc: namhyung@kernel.org
Cc: yabinc@google.com
Link: http://lkml.kernel.org/r/20190517115418.481392777@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-24 09:00:11 +02:00
..
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
callchain.c perf/core: Convert to SPDX license identifiers 2019-02-04 08:46:11 +01:00
core.c perf/core: Add perf_pmu_resched() as global function 2019-04-16 12:19:34 +02:00
hw_breakpoint.c perf/hw_breakpoints: Convert to SPDX license identifier 2019-02-04 08:46:13 +01:00
internal.h perf/ring-buffer: Use regular variables for nesting 2019-05-24 09:00:11 +02:00
ring_buffer.c perf/ring-buffer: Use regular variables for nesting 2019-05-24 09:00:11 +02:00
uprobes.c mm/mmu_notifier: use correct mmu_notifier events for each invalidation 2019-05-14 09:47:49 -07:00