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authorSean Christopherson <seanjc@google.com>2021-11-11 02:07:25 +0000
committerPeter Zijlstra <peterz@infradead.org>2021-11-17 14:49:07 +0100
commit2934e3d09350c1a7ca2433fbeabfcd831e48a575 (patch)
tree0bfc6eb877186cd540ddf25b301692f57c9b320c /kernel/events
parentf4b027c5c8199abd4fb6f00d67d380548dbfdfa8 (diff)
perf: Stop pretending that perf can handle multiple guest callbacks
Drop the 'int' return value from the perf (un)register callbacks helpers and stop pretending perf can support multiple callbacks. The 'int' returns are not future proofing anything as none of the callers take action on an error. It's also not obvious that there will ever be co-tenant hypervisors, and if there are, that allowing multiple callbacks to be registered is desirable or even correct. Opportunistically rename callbacks=>cbs in the affected declarations to match their definitions. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20211111020738.2512932-5-seanjc@google.com
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c15
1 files changed, 4 insertions, 11 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index c552e1bfcaea..17e5b20762c5 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6521,31 +6521,24 @@ static void perf_pending_event(struct irq_work *entry)
perf_swevent_put_recursion_context(rctx);
}
-/*
- * We assume there is only KVM supporting the callbacks.
- * Later on, we might change it to a list if there is
- * another virtualization implementation supporting the callbacks.
- */
struct perf_guest_info_callbacks __rcu *perf_guest_cbs;
-int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
+void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
{
if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs)))
- return -EBUSY;
+ return;
rcu_assign_pointer(perf_guest_cbs, cbs);
- return 0;
}
EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
-int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
+void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
{
if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs) != cbs))
- return -EINVAL;
+ return;
rcu_assign_pointer(perf_guest_cbs, NULL);
synchronize_rcu();
- return 0;
}
EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);