linux/include
Christoph Lameter b263295dbf x86: 64-bit, make sparsemem vmemmap the only memory model
Use sparsemem as the only memory model for UP, SMP and NUMA.  Measurements
indicate that DISCONTIGMEM has a higher overhead than sparsemem.  And
FLATMEMs benefits are minimal.  So I think its best to simply standardize
on sparsemem.

Results of page allocator tests (test can be had via git from slab git
tree branch tests)

Measurements in cycle counts. 1000 allocations were performed and then the
average cycle count was calculated.

Order	FlatMem	Discontig	SparseMem
0	  639	  665		  641
1	  567	  647		  593
2	  679	  774		  692
3	  763	  967		  781
4	  961	 1501		  962
5	 1356	 2344		 1392
6	 2224	 3982		 2336
7	 4869	 7225		 5074
8	12500	14048		12732
9	27926	28223		28165
10	58578	58714		58682

(Note that FlatMem is an SMP config and the rest NUMA configurations)

Memory use:

SMP Sparsemem
-------------

Kernel size:

   text    data     bss     dec     hex filename
3849268  397739 1264856 5511863  541ab7 vmlinux

             total       used       free     shared    buffers     cached
Mem:       8242252      41164    8201088          0        352      11512
-/+ buffers/cache:      29300    8212952
Swap:      9775512          0    9775512

SMP Flatmem
-----------

Kernel size:

   text    data     bss     dec     hex filename
3844612  397739 1264536 5506887  540747 vmlinux

So 4.5k growth in text size vs. FLATMEM.

             total       used       free     shared    buffers     cached
Mem:       8244052      40544    8203508          0        352      11484
-/+ buffers/cache:      28708    8215344

2k growth in overall memory use after boot.

NUMA discontig:

   text    data     bss     dec     hex filename
3888124  470659 1276504 5635287  55fcd7 vmlinux

             total       used       free     shared    buffers     cached
Mem:       8256256      56908    8199348          0        352      11496
-/+ buffers/cache:      45060    8211196
Swap:      9775512          0    9775512

NUMA sparse:

   text    data     bss     dec     hex filename
3896428  470659 1276824 5643911  561e87 vmlinux

8k text growth. Given that we fully inline virt_to_page and friends now
that is rather good.

             total       used       free     shared    buffers     cached
Mem:       8264720      57240    8207480          0        352      11516
-/+ buffers/cache:      45372    8219348
Swap:      9775512          0    9775512

The total available memory is increased by 8k.

This patch makes sparsemem the default and removes discontig and
flatmem support from x86.

[ akpm@linux-foundation.org: allnoconfig build fix ]

Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:47 +01:00
..
acpi kobject: convert /sys/firmware/acpi/ to use kobject_create 2008-01-24 20:40:23 -08:00
asm-alpha alpha: build fixes 2007-12-17 19:28:16 -08:00
asm-arm ext4: Add ext4_find_next_bit() 2008-01-28 23:58:27 -05:00
asm-avr32 remove __attribute_used__ 2008-01-28 23:21:18 +01:00
asm-blackfin [Blackfin] arch: Add the semtimedop syscall. Upstream uClibc doesn't compile without it. 2008-01-27 19:56:43 +08:00
asm-cris ide: remove stale ide.h "configuration options" 2008-01-25 22:17:08 +01:00
asm-frv ide: remove stale ide.h "configuration options" 2008-01-25 22:17:08 +01:00
asm-generic Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild 2008-01-29 22:46:14 +11:00
asm-h8300 asm-h8300: parentheses around definition CLOCK_TICK_RATE 2007-12-10 19:43:54 -08:00
asm-ia64 remove __attribute_used__ 2008-01-28 23:21:18 +01:00
asm-m32r m32r: Update sys_rt_sigsuspend 2007-11-28 01:24:04 +09:00
asm-m68k ext4: Add ext4_find_next_bit() 2008-01-28 23:58:27 -05:00
asm-m68knommu ext4: Add ext4_find_next_bit() 2008-01-28 23:58:27 -05:00
asm-mips [MIPS] Malta, Atlas: move an extern function declaration to the header file 2008-01-29 10:15:05 +00:00
asm-parisc [PARISC] print more than one character at a time for pdc console 2007-12-06 09:32:15 -08:00
asm-powerpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25 2008-01-29 22:54:01 +11:00
asm-ppc
asm-s390 ext4: Add ext4_find_next_bit() 2008-01-28 23:58:27 -05:00
asm-sh remove __attribute_used__ 2008-01-28 23:21:18 +01:00
asm-sparc [SPARC32]: Silence sparc32 warnings on missing syscalls. 2007-12-14 10:59:50 -08:00
asm-sparc64 [SPARC64]: Implement pci_resource_to_user() 2007-12-26 19:33:46 -08:00
asm-um uml: update address space affected by pud_clear 2007-11-14 18:45:37 -08:00
asm-v850
asm-x86 x86: 64-bit, make sparsemem vmemmap the only memory model 2008-01-30 13:30:47 +01:00
asm-xtensa
crypto [CRYPTO] api: Include sched.h for cond_resched in scatterwalk.h 2008-01-11 08:16:59 +11:00
keys
linux x86: remove extern declarations for code, data, bss resources 2008-01-30 13:30:32 +01:00
math-emu
media i2c: Constify client address data 2008-01-27 18:14:46 +01:00
mtd
net [NET_SCHED]: act_api: use PTR_ERR in tcf_action_init/tcf_action_get 2008-01-28 15:11:17 -08:00
pcmcia [AVR32] pcmcia ioaddr_t should be 32 bits on AVR32 2007-11-15 13:47:19 +01:00
rdma RDMA/cma: add support for rdma_migrate_id() 2008-01-25 14:15:32 -08:00
rxrpc
scsi SG: Convert SCSI to use scatterlist helpers for sg chaining 2008-01-28 10:05:27 +01:00
sound [ALSA] version 1.0.15 2007-11-20 20:16:43 +01:00
video
xen
Kbuild