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. Link: https://lkml.kernel.org/r/20220504010716.661115-5-Liam.Howlett@xxxxxxxxxx Link: https://lkml.kernel.org/r/20220621204632.3370049-4-Liam.Howlett@xxxxxxxxxx Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: David Howells <dhowells@xxxxxxxxxx> Cc: SeongJae Park <sj@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/radix-tree/linux.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/tools/testing/radix-tree/linux.c b/tools/testing/radix-tree/linux.c index d5c1bcba86fe..277aa8b70abc 100644 --- a/tools/testing/radix-tree/linux.c +++ b/tools/testing/radix-tree/linux.c @@ -23,15 +23,26 @@ 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_lru(struct kmem_cache *cachep, struct list_lru *lru, 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) { @@ -90,5 +101,6 @@ 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; } -- 2.35.1
