slab: remove unused PREEMPT_RT specific macros

The macros slub_get_cpu_ptr()/slub_put_cpu_ptr() are now unused, remove
them. USE_LOCKLESS_FAST_PATH() has lost its true meaning with the code
being removed. The only remaining usage is in fact testing whether we
can assert irqs disabled, because spin_lock_irqsave() only does that on
!RT. Test for CONFIG_PREEMPT_RT instead.

Reviewed-by: Hao Li <hao.li@linux.dev>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/mm/slub.c b/mm/slub.c
index 8e4482e75a5cc6d569f58219c93d21cb98c3669e..697d3d6cebd33c98169b44efa7d73d9613ffabd6 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -201,28 +201,6 @@ enum slab_flags {
        SL_pfmemalloc = PG_active,      /* Historical reasons for this bit */
 };
 
-/*
- * We could simply use migrate_disable()/enable() but as long as it's a
- * function call even on !PREEMPT_RT, use inline preempt_disable() there.
- */
-#ifndef CONFIG_PREEMPT_RT
-#define slub_get_cpu_ptr(var)          get_cpu_ptr(var)
-#define slub_put_cpu_ptr(var)          put_cpu_ptr(var)
-#define USE_LOCKLESS_FAST_PATH()       (true)
-#else
-#define slub_get_cpu_ptr(var)          \
-({                                     \
-       migrate_disable();              \
-       this_cpu_ptr(var);              \
-})
-#define slub_put_cpu_ptr(var)          \
-do {                                   \
-       (void)(var);                    \
-       migrate_enable();               \
-} while (0)
-#define USE_LOCKLESS_FAST_PATH()       (false)
-#endif
-
 #ifndef CONFIG_SLUB_TINY
 #define __fastpath_inline __always_inline
 #else
@@ -713,7 +691,7 @@ static inline bool __slab_update_freelist(struct kmem_cache *s, struct slab *sla
 {
        bool ret;
 
-       if (USE_LOCKLESS_FAST_PATH())
+       if (!IS_ENABLED(CONFIG_PREEMPT_RT))
                lockdep_assert_irqs_disabled();
 
        if (s->flags & __CMPXCHG_DOUBLE)