From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Instead of storing stack records in stack depot pools one right after
another, use 32-frame-sized slots.
This is preparatory patch for implementing the eviction of stack records
from the stack depot.
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
lib/stackdepot.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 2128108f2acb..93191ee70fc3 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -42,6 +42,7 @@
#define DEPOT_MAX_POOLS \
(((1LL << (DEPOT_POOL_INDEX_BITS)) < DEPOT_POOLS_CAP) ? \
(1LL << (DEPOT_POOL_INDEX_BITS)) : DEPOT_POOLS_CAP)
+#define DEPOT_STACK_MAX_FRAMES 32
/* Compact structure that stores a reference to a stack. */
union handle_parts {
@@ -58,9 +59,12 @@ struct stack_record {
u32 hash; /* Hash in the hash table */
u32 size; /* Number of stored frames */
union handle_parts handle;
- unsigned long entries[]; /* Variable-sized array of frames */
+ unsigned long entries[DEPOT_STACK_MAX_FRAMES]; /* Frames */
};
+#define DEPOT_STACK_RECORD_SIZE \
+ ALIGN(sizeof(struct stack_record), 1 << DEPOT_STACK_ALIGN)
+
static bool stack_depot_disabled;
static bool __stack_depot_early_init_requested __initdata = IS_ENABLED(CONFIG_STACKDEPOT_ALWAYS_INIT);
static bool __stack_depot_early_init_passed __initdata;
@@ -258,9 +262,7 @@ static struct stack_record *
depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc)
{
struct stack_record *stack;
- size_t required_size = struct_size(stack, entries, size);
-
- required_size = ALIGN(required_size, 1 << DEPOT_STACK_ALIGN);
+ size_t required_size = DEPOT_STACK_RECORD_SIZE;
/* Check if there is not enough space in the current pool. */
if (unlikely(pool_offset + required_size > DEPOT_POOL_SIZE)) {
@@ -295,6 +297,10 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc)
if (stack_pools[pool_index] == NULL)
return NULL;
+ /* Limit number of saved frames to DEPOT_STACK_MAX_FRAMES. */
+ if (size > DEPOT_STACK_MAX_FRAMES)
+ size = DEPOT_STACK_MAX_FRAMES;
+
/* Save the stack trace. */
stack = stack_pools[pool_index] + pool_offset;
stack->hash = hash;
--
2.25.1
