Commit 0aa817f0 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

Slab allocators: define common size limitations 



Currently we have a maze of configuration variables that determine the
maximum slab size.  Worst of all it seems to vary between SLAB and SLUB.

So define a common maximum size for kmalloc.  For conveniences sake we use
the maximum size ever supported which is 32 MB.  We limit the maximum size
to a lower limit if MAX_ORDER does not allow such large allocations.

For many architectures this patch will have the effect of adding large
kmalloc sizes.  x86_64 adds 5 new kmalloc sizes.  So a small amount of
memory will be needed for these caches (contemporary SLAB has dynamically
sizeable node and cpu structure so the waste is less than in the past)

Most architectures will then be able to allocate object with sizes up to
MAX_ORDER.  We have had repeated breakage (in fact whenever we doubled the
number of supported processors) on IA64 because one or the other struct
grew beyond what the slab allocators supported.  This will avoid future
issues and f.e.  avoid fixes for 2k and 4k cpu support.

CONFIG_LARGE_ALLOCS is no longer necessary so drop it.

It fixes sparc64 with SLAB.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatar"David S. Miller" <davem@davemloft.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3ec09742

arch/blackfin/Kconfig

+0 −8
Original line number Diff line number Diff line
@@ -560,14 +560,6 @@ endchoice 


source "mm/Kconfig"



config LARGE_ALLOCS

	bool "Allow allocating large blocks (> 1MB) of memory"

	help

	  Allow the slab memory allocator to keep chains for very large

	  memory sizes - upto 32MB. You may need this if your system has

	  a lot of RAM, and you need to able to allocate very large

	  contiguous chunks. If unsure, say N.



config BFIN_DMA_5XX

	bool "Enable DMA Support"

	depends on (BF533 || BF532 || BF531 || BF537 || BF536 || BF534 || BF561)

arch/frv/Kconfig

+0 −8
Original line number Diff line number Diff line
@@ -102,14 +102,6 @@ config HIGHPTE 
	  with a lot of RAM, this can be wasteful of precious low memory.

	  Setting this option will put user-space page tables in high memory.



config LARGE_ALLOCS

	bool "Allow allocating large blocks (> 1MB) of memory"

	help

	  Allow the slab memory allocator to keep chains for very large memory

	  sizes - up to 32MB. You may need this if your system has a lot of

	  RAM, and you need to able to allocate very large contiguous chunks.

	  If unsure, say N.



source "mm/Kconfig"



choice

arch/m68knommu/Kconfig

+0 −8
Original line number Diff line number Diff line
@@ -470,14 +470,6 @@ config AVNET 
	default y

	depends on (AVNET5282)



config LARGE_ALLOCS

	bool "Allow allocating large blocks (> 1MB) of memory"

	help

	  Allow the slab memory allocator to keep chains for very large

	  memory sizes - upto 32MB. You may need this if your system has

	  a lot of RAM, and you need to able to allocate very large

	  contiguous chunks. If unsure, say N.



config 4KSTACKS

	bool "Use 4Kb for kernel stacks instead of 8Kb"

	default y

arch/v850/Kconfig

+0 −8
Original line number Diff line number Diff line
@@ -240,14 +240,6 @@ menu "Processor type and features" 
   config RESET_GUARD

   	  bool "Reset Guard"



   config LARGE_ALLOCS

	  bool "Allow allocating large blocks (> 1MB) of memory"

	  help

	     Allow the slab memory allocator to keep chains for very large

	     memory sizes - upto 32MB. You may need this if your system has

	     a lot of RAM, and you need to able to allocate very large

	     contiguous chunks. If unsure, say N.



source "mm/Kconfig"



endmenu

include/linux/kmalloc_sizes.h

+15 −5
Original line number Diff line number Diff line
@@ -19,17 +19,27 @@ 
	CACHE(32768)

	CACHE(65536)

	CACHE(131072)

#if (NR_CPUS > 512) || (MAX_NUMNODES > 256) || !defined(CONFIG_MMU)

#if KMALLOC_MAX_SIZE >= 262144

	CACHE(262144)

#endif

#ifndef CONFIG_MMU

#if KMALLOC_MAX_SIZE >= 524288

	CACHE(524288)

#endif

#if KMALLOC_MAX_SIZE >= 1048576

	CACHE(1048576)

#ifdef CONFIG_LARGE_ALLOCS

#endif

#if KMALLOC_MAX_SIZE >= 2097152

	CACHE(2097152)

#endif

#if KMALLOC_MAX_SIZE >= 4194304

	CACHE(4194304)

#endif

#if KMALLOC_MAX_SIZE >= 8388608

	CACHE(8388608)

#endif

#if KMALLOC_MAX_SIZE >= 16777216

	CACHE(16777216)

#endif

#if KMALLOC_MAX_SIZE >= 33554432

	CACHE(33554432)

#endif /* CONFIG_LARGE_ALLOCS */

#endif /* CONFIG_MMU */
 
#endif

CRA Git | Maintained and supported by SUSTech CRA and CCSE