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author | Marco Elver <elver@google.com> | 2022-08-29 14:47:07 +0200 |
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committer | Peter Zijlstra <peterz@infradead.org> | 2022-08-30 10:56:20 +0200 |
commit | c5b81449f915a28bb9c7725e53aebab3ba39b4a2 (patch) | |
tree | 1cd3e781dfed0f8a271bd0987aa26e4979dc3a3b /kernel/events/hw_breakpoint.c | |
parent | 724c299c6a0e412b5679d7ebb9b3f4e00bd2aa78 (diff) | |
download | linux-stable-c5b81449f915a28bb9c7725e53aebab3ba39b4a2.tar.gz linux-stable-c5b81449f915a28bb9c7725e53aebab3ba39b4a2.tar.bz2 linux-stable-c5b81449f915a28bb9c7725e53aebab3ba39b4a2.zip |
perf/hw_breakpoint: Provide hw_breakpoint_is_used() and use in test
Provide hw_breakpoint_is_used() to check if breakpoints are in use on
the system.
Use it in the KUnit test to verify the global state before and after a
test case.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20220829124719.675715-3-elver@google.com
Diffstat (limited to 'kernel/events/hw_breakpoint.c')
-rw-r--r-- | kernel/events/hw_breakpoint.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index f32320ac02fd..fd5cd1f9e7fc 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -604,6 +604,35 @@ void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) } EXPORT_SYMBOL_GPL(unregister_wide_hw_breakpoint); +/** + * hw_breakpoint_is_used - check if breakpoints are currently used + * + * Returns: true if breakpoints are used, false otherwise. + */ +bool hw_breakpoint_is_used(void) +{ + int cpu; + + if (!constraints_initialized) + return false; + + for_each_possible_cpu(cpu) { + for (int type = 0; type < TYPE_MAX; ++type) { + struct bp_cpuinfo *info = get_bp_info(cpu, type); + + if (info->cpu_pinned) + return true; + + for (int slot = 0; slot < nr_slots[type]; ++slot) { + if (info->tsk_pinned[slot]) + return true; + } + } + } + + return false; +} + static struct notifier_block hw_breakpoint_exceptions_nb = { .notifier_call = hw_breakpoint_exceptions_notify, /* we need to be notified first */ |