From: Hou Tao <houtao1@xxxxxxxxxx>
Add bpf_mem_cache_is_mergeable() to check whether two bpf mem allocator
for fixed-size objects are mergeable or not. The merging could reduce
the memory overhead of bpf mem allocator.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
include/linux/bpf_mem_alloc.h | 1 +
kernel/bpf/memalloc.c | 12 ++++++++++++
2 files changed, 13 insertions(+)
diff --git a/include/linux/bpf_mem_alloc.h b/include/linux/bpf_mem_alloc.h
index e45162ef59bb..faa54b9c7a04 100644
--- a/include/linux/bpf_mem_alloc.h
+++ b/include/linux/bpf_mem_alloc.h
@@ -47,5 +47,6 @@ void bpf_mem_cache_free(struct bpf_mem_alloc *ma, void *ptr);
void bpf_mem_cache_free_rcu(struct bpf_mem_alloc *ma, void *ptr);
void bpf_mem_cache_raw_free(void *ptr);
void *bpf_mem_cache_alloc_flags(struct bpf_mem_alloc *ma, gfp_t flags);
+bool bpf_mem_cache_is_mergeable(size_t size, size_t new_size, bool percpu);
#endif /* _BPF_MEM_ALLOC_H */
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index 889374722d0a..49dd08ad1d4f 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -1014,3 +1014,15 @@ int bpf_mem_alloc_check_size(bool percpu, size_t size)
return 0;
}
+
+bool bpf_mem_cache_is_mergeable(size_t size, size_t new_size, bool percpu)
+{
+ /* Only for fixed-size object allocator */
+ if (!size || !new_size)
+ return false;
+
+ return (percpu && ALIGN(size, PCPU_MIN_ALLOC_SIZE) ==
+ ALIGN(new_size, PCPU_MIN_ALLOC_SIZE)) ||
+ (!percpu && kmalloc_size_roundup(size + LLIST_NODE_SZ) ==
+ kmalloc_size_roundup(new_size + LLIST_NODE_SZ));
+}
--
2.29.2
