perf: Fix and clean up initialization of pmu::event_idx

Andy reported that the current state of event_idx is rather confused.
So remove all but the x86_pmu implementation and change the default to
return 0 (the safe option).

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Cody P Schafer <dev@codyps.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Himangi Saraogi <himangi774@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: sukadev@linux.vnet.ibm.com <sukadev@linux.vnet.ibm.com>
Cc: Thomas Huth <thuth@linux.vnet.ibm.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux390@de.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 1 insertions, 21 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1425d07018de..2b02c9fda790 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6071,11 +6071,6 @@ static int perf_swevent_init(struct perf_event *event)
         return 0;
 }
 
-static int perf_swevent_event_idx(struct perf_event *event)
-{
-        return 0;
-}
-
 static struct pmu perf_swevent = {
         .task_ctx_nr    = perf_sw_context,
 
@@ -6085,8 +6080,6 @@ static struct pmu perf_swevent = {
         .start          = perf_swevent_start,
         .stop           = perf_swevent_stop,
         .read           = perf_swevent_read,
-
-        .event_idx      = perf_swevent_event_idx,
 };
 
 #ifdef CONFIG_EVENT_TRACING
@@ -6204,8 +6197,6 @@ static struct pmu perf_tracepoint = {
         .start          = perf_swevent_start,
         .stop           = perf_swevent_stop,
         .read           = perf_swevent_read,
-
-        .event_idx      = perf_swevent_event_idx,
 };
 
 static inline void perf_tp_register(void)
@@ -6431,8 +6422,6 @@ static struct pmu perf_cpu_clock = {
         .start          = cpu_clock_event_start,
         .stop           = cpu_clock_event_stop,
         .read           = cpu_clock_event_read,
-
-        .event_idx      = perf_swevent_event_idx,
 };
 
 /*
@@ -6511,8 +6500,6 @@ static struct pmu perf_task_clock = {
         .start          = task_clock_event_start,
         .stop           = task_clock_event_stop,
         .read           = task_clock_event_read,
-
-        .event_idx      = perf_swevent_event_idx,
 };
 
 static void perf_pmu_nop_void(struct pmu *pmu)
@@ -6542,7 +6529,7 @@ static void perf_pmu_cancel_txn(struct pmu *pmu)
 
 static int perf_event_idx_default(struct perf_event *event)
 {
-        return event->hw.idx + 1;
+        return 0;
 }
 
 /*
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 1559fb0b9296..9803a6600d49 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -605,11 +605,6 @@ static void hw_breakpoint_stop(struct perf_event *bp, int flags)
         bp->hw.state = PERF_HES_STOPPED;
 }
 
-static int hw_breakpoint_event_idx(struct perf_event *bp)
-{
-        return 0;
-}
-
 static struct pmu perf_breakpoint = {
         .task_ctx_nr    = perf_sw_context, /* could eventually get its own */
 
@@ -619,8 +614,6 @@ static struct pmu perf_breakpoint = {
         .start          = hw_breakpoint_start,
         .stop           = hw_breakpoint_stop,
         .read           = hw_breakpoint_pmu_read,
-
-        .event_idx      = hw_breakpoint_event_idx,
 };
 
 int __init init_hw_breakpoint(void)