[PATCH v5 03/70] radix tree test suite: Add kmem_cache_set_non_kernel()

From: Liam Howlett
Date: Tue Feb 01 2022 - 21:42:13 EST


From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>

kmem_cache_set_non_kernel() is a mechanism to allow a certain number of
kmem_cache_alloc requests to succeed even when GFP_KERNEL is not set in
the flags. This functionality allows for testing different paths though
the code.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
tools/testing/radix-tree/linux.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/tools/testing/radix-tree/linux.c b/tools/testing/radix-tree/linux.c
index 2d9c59df60de..00ee01a14652 100644
--- a/tools/testing/radix-tree/linux.c
+++ b/tools/testing/radix-tree/linux.c
@@ -24,14 +24,24 @@ struct kmem_cache {
int nr_objs;
void *objs;
void (*ctor)(void *);
+ unsigned int non_kernel;
};

+void kmem_cache_set_non_kernel(struct kmem_cache *cachep, unsigned int val)
+{
+ cachep->non_kernel = val;
+}
+
void *kmem_cache_alloc(struct kmem_cache *cachep, int gfp)
{
void *p;

- if (!(gfp & __GFP_DIRECT_RECLAIM))
- return NULL;
+ if (!(gfp & __GFP_DIRECT_RECLAIM)) {
+ if (!cachep->non_kernel)
+ return NULL;
+
+ cachep->non_kernel--;
+ }

pthread_mutex_lock(&cachep->lock);
if (cachep->nr_objs) {
@@ -116,5 +126,6 @@ kmem_cache_create(const char *name, unsigned int size, unsigned int align,
ret->nr_objs = 0;
ret->objs = NULL;
ret->ctor = ctor;
+ ret->non_kernel = 0;
return ret;
}
--
2.34.1