lib min_heap: add type safe interface

Implement a type-safe interface for min_heap using strong type pointers
instead of void * in the data field.  This change includes adding small
macro wrappers around functions, enabling the use of __minheap_cast and
__minheap_obj_size macros for type casting and obtaining element size. 
This implementation removes the necessity of passing element size in
min_heap_callbacks.  Additionally, introduce the MIN_HEAP_PREALLOCATED
macro for preallocating some elements.

Link: https://lkml.kernel.org/ioyfizrzq7w7mjrqcadtzsfgpuntowtjdw5pgn4qhvsdp4mqqg@nrlek5vmisbu
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Bagas Sanjaya <[email protected]>
Cc: Brian Foster <[email protected]>
Cc: Ching-Chun (Jim) Huang <[email protected]>
Cc: Coly Li <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Matthew Sakai <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Randy Dunlap <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 6 insertions, 5 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index effe9c15ec7d..5ae4e429b3fb 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3701,13 +3701,14 @@ static void swap_ptr(void *l, void *r)
 	swap(*lp, *rp);
 }
 
+DEFINE_MIN_HEAP(struct perf_event *, perf_event_min_heap);
+
 static const struct min_heap_callbacks perf_min_heap = {
-	.elem_size = sizeof(struct perf_event *),
 	.less = perf_less_group_idx,
 	.swp = swap_ptr,
 };
 
-static void __heap_add(struct min_heap *heap, struct perf_event *event)
+static void __heap_add(struct perf_event_min_heap *heap, struct perf_event *event)
 {
 	struct perf_event **itrs = heap->data;
 
@@ -3741,7 +3742,7 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,
 	struct perf_cpu_context *cpuctx = NULL;
 	/* Space for per CPU and/or any CPU event iterators. */
 	struct perf_event *itrs[2];
-	struct min_heap event_heap;
+	struct perf_event_min_heap event_heap;
 	struct perf_event **evt;
 	int ret;
 
@@ -3750,7 +3751,7 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,
 
 	if (!ctx->task) {
 		cpuctx = this_cpu_ptr(&perf_cpu_context);
-		event_heap = (struct min_heap){
+		event_heap = (struct perf_event_min_heap){
 			.data = cpuctx->heap,
 			.nr = 0,
 			.size = cpuctx->heap_size,
@@ -3763,7 +3764,7 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,
 			css = &cpuctx->cgrp->css;
 #endif
 	} else {
-		event_heap = (struct min_heap){
+		event_heap = (struct perf_event_min_heap){
 			.data = itrs,
 			.nr = 0,
 			.size = ARRAY_SIZE(itrs),