| From: Ingo Molnar <mingo@elte.hu> |
| Date: Fri, 3 Jul 2009 08:44:03 -0500 |
| Subject: mm: Allow only SLUB on RT |
| |
| Memory allocation disables interrupts as part of the allocation and freeing |
| process. For -RT it is important that this section remain short and don't |
| depend on the size of the request or an internal state of the memory allocator. |
| At the beginning the SLAB memory allocator was adopted for RT's needs and it |
| required substantial changes. Later, with the addition of the SLUB memory |
| allocator we adopted this one as well and the changes were smaller. More |
| important, due to the design of the SLUB allocator it performs better and its |
| worst case latency was smaller. In the end only SLUB remained supported. |
| |
| Disable SLAB and SLOB on -RT. Only SLUB is adopted to -RT needs. |
| |
| Signed-off-by: Ingo Molnar <mingo@elte.hu> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| --- |
| init/Kconfig | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/init/Kconfig |
| +++ b/init/Kconfig |
| @@ -1781,6 +1781,7 @@ choice |
| |
| config SLAB |
| bool "SLAB" |
| + depends on !PREEMPT_RT |
| select HAVE_HARDENED_USERCOPY_ALLOCATOR |
| help |
| The regular slab allocator that is established and known to work |
| @@ -1801,6 +1802,7 @@ config SLUB |
| config SLOB |
| depends on EXPERT |
| bool "SLOB (Simple Allocator)" |
| + depends on !PREEMPT_RT |
| help |
| SLOB replaces the stock allocator with a drastically simpler |
| allocator. SLOB is generally more space efficient but |
