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 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -577,14 +577,11 @@ config SLUB
           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.

diff --cc mm/slob.c
Simple merge