On Wed, Sep 10, 2025 at 1:01 AM Vlastimil Babka <vbabka@suse.cz> wrote:
>
> From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
>
> liburcu doesn't have kfree_rcu (or anything similar). Despite that, we
> can hack around it in a trivial fashion, by adding a wrapper.
>
> The wrapper only works for maple_nodes because we cannot get the
> kmem_cache pointer any other way in the test code.
>
> Link: https://lore.kernel.org/all/20250812162124.59417-1-pfalcato@suse.de/
> Suggested-by: Pedro Falcato <pfalcato@suse.de>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
With one nit below:
> ---
> tools/testing/shared/maple-shared.h | 11 +++++++++++
> tools/testing/shared/maple-shim.c | 6 ++++++
> 2 files changed, 17 insertions(+)
>
> diff --git a/tools/testing/shared/maple-shared.h b/tools/testing/shared/maple-shared.h
> index dc4d30f3860b9bd23b4177c7d7926ac686887815..2a1e9a8594a2834326cd9374738b2a2c7c3f9f7c 100644
> --- a/tools/testing/shared/maple-shared.h
> +++ b/tools/testing/shared/maple-shared.h
> @@ -10,4 +10,15 @@
> #include <time.h>
> #include "linux/init.h"
>
> +void maple_rcu_cb(struct rcu_head *head);
> +#define rcu_cb maple_rcu_cb
> +
> +#define kfree_rcu(_struct, _memb) \
> +do { \
> + typeof(_struct) _p_struct = (_struct); \
Maybe add an assertion that (typeof(_struct) == typeof(struct
maple_node)) to make sure kfree_rcu() is not used for anything else in
the tests?
> + \
> + call_rcu(&((_p_struct)->_memb), rcu_cb); \
> +} while(0);
> +
> +
> #endif /* __MAPLE_SHARED_H__ */
> diff --git a/tools/testing/shared/maple-shim.c b/tools/testing/shared/maple-shim.c
> index 9d7b743415660305416e972fa75b56824211b0eb..16252ee616c0489c80490ff25b8d255427bf9fdc 100644
> --- a/tools/testing/shared/maple-shim.c
> +++ b/tools/testing/shared/maple-shim.c
> @@ -6,3 +6,9 @@
> #include <linux/slab.h>
>
> #include "../../../lib/maple_tree.c"
> +
> +void maple_rcu_cb(struct rcu_head *head) {
> + struct maple_node *node = container_of(head, struct maple_node, rcu);
> +
> + kmem_cache_free(maple_node_cache, node);
> +}
>
> --
> 2.51.0
>