mm/slob: remove CONFIG_SLOB

Remove SLOB from Kconfig and Makefile. Everything under #ifdef
CONFIG_SLOB, and mm/slob.c is now dead code.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

init/Kconfig

@@ -973,7 +973,7 @@ config MEMCG
 
 config MEMCG_KMEM
 	bool
-	depends on MEMCG && !SLOB
+	depends on MEMCG
 	default y
 
 config BLK_CGROUP

kernel/configs/tiny.config

@@ -7,6 +7,5 @@ CONFIG_KERNEL_XZ=y
 # CONFIG_KERNEL_LZO is not set
 # CONFIG_KERNEL_LZ4 is not set
 # CONFIG_SLAB is not set
-# CONFIG_SLOB_DEPRECATED is not set
 CONFIG_SLUB=y
 CONFIG_SLUB_TINY=y

mm/Kconfig

@@ -238,30 +238,8 @@ config SLUB
 	   and has enhanced diagnostics. SLUB is the default choice for
 	   a slab allocator.
 
-config SLOB_DEPRECATED
-	depends on EXPERT
-	bool "SLOB (Simple Allocator - DEPRECATED)"
-	depends on !PREEMPT_RT
-	help
-	   Deprecated and scheduled for removal in a few cycles. SLUB
-	   recommended as replacement. CONFIG_SLUB_TINY can be considered
-	   on systems with 16MB or less RAM.
-
-	   If you need SLOB to stay, please contact linux-mm@kvack.org and
-	   people listed in the SLAB ALLOCATOR section of MAINTAINERS file,
-	   with your use case.
-
-	   SLOB replaces the stock allocator with a drastically simpler
-	   allocator. SLOB is generally more space efficient but
-	   does not perform as well on large systems.
-
 endchoice
 
-config SLOB
-	bool
-	default y
-	depends on SLOB_DEPRECATED
-
 config SLUB_TINY
 	bool "Configure SLUB for minimal memory footprint"
 	depends on SLUB && EXPERT

mm/Makefile

@@ -22,7 +22,6 @@ KCSAN_INSTRUMENT_BARRIERS := y
 # flaky coverage that is not a function of syscall inputs. E.g. slab is out of
 # free pages, or a task is migrated between nodes.
 KCOV_INSTRUMENT_slab_common.o := n
-KCOV_INSTRUMENT_slob.o := n
 KCOV_INSTRUMENT_slab.o := n
 KCOV_INSTRUMENT_slub.o := n
 KCOV_INSTRUMENT_page_alloc.o := n
@@ -81,7 +80,6 @@ obj-$(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)	+= hugetlb_vmemmap.o
 obj-$(CONFIG_NUMA) 	+= mempolicy.o
 obj-$(CONFIG_SPARSEMEM)	+= sparse.o
 obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
-obj-$(CONFIG_SLOB) += slob.o
 obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
 obj-$(CONFIG_KSM) += ksm.o
 obj-$(CONFIG_PAGE_POISONING) += page_poison.o