slob: implement RCU freeing
The SLOB allocator should implement SLAB_DESTROY_BY_RCU correctly, because
even on UP, RCU freeing semantics are not equivalent to simply freeing
immediately. This also allows SLOB to be used on SMP.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/init/Kconfig b/init/Kconfig
index 4e009fd..9264895 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -577,14 +577,11 @@
and has enhanced diagnostics.
config SLOB
-#
-# SLOB does not support SMP because SLAB_DESTROY_BY_RCU is unsupported
-#
- depends on EMBEDDED && !SMP && !SPARSEMEM
+ depends on EMBEDDED && !SPARSEMEM
bool "SLOB (Simple Allocator)"
help
SLOB replaces the SLAB allocator with a drastically simpler
- allocator. SLOB is more space efficient that SLAB but does not
+ allocator. SLOB is more space efficient than SLAB but does not
scale well (single lock for all operations) and is also highly
susceptible to fragmentation. SLUB can accomplish a higher object
density. It is usually better to use SLUB instead of SLOB.