Commit graph

31 commits

Author SHA1 Message Date
Yinghai Lu
b7ad149d62 x86: reenable support for system without on node0
One system doesn't have RAM for node0 installed.

SRAT: PXM 0 -> APIC 0 -> Node 0
SRAT: PXM 0 -> APIC 1 -> Node 0
SRAT: PXM 1 -> APIC 2 -> Node 1
SRAT: PXM 1 -> APIC 3 -> Node 1
SRAT: Node 1 PXM 1 0-a0000
SRAT: Node 1 PXM 1 0-dd000000
SRAT: Node 1 PXM 1 0-123000000
ACPI: SLIT: nodes = 2
 10 13
 13 10
mapped APIC to ffffffffff5fb000 (        fee00000)
Bootmem setup node 1 0000000000000000-0000000123000000
  NODE_DATA [000000000000e000 - 0000000000014fff]
  bootmap [0000000000015000 -  00000000000395ff] pages 25
Could not find start_pfn for node 0
Pid: 0, comm: swapper Not tainted 2.6.24-smp-g5a514e21-dirty #14

Call Trace:
 [<ffffffff80bab498>] free_area_init_node+0x22/0x381
 [<ffffffff8045ffc5>] generic_swap+0x0/0x17
 [<ffffffff80bab0cc>] find_zone_movable_pfns_for_nodes+0x54/0x271
 [<ffffffff80baba5f>] free_area_init_nodes+0x239/0x287
 [<ffffffff80ba6311>] paging_init+0x46/0x4c
 [<ffffffff80b9dda5>] setup_arch+0x3c3/0x44e
 [<ffffffff80b978be>] start_kernel+0x6f/0x2c7
 [<ffffffff80b971cc>] _sinittext+0x1cc/0x1d3

This happens because node 0 is not online, but the node state in
mm/page_alloc.c has node 0 set.

        nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
                [N_POSSIBLE] = NODE_MASK_ALL,
                [N_ONLINE] = { { [0] = 1UL } },

So we need to clear node_online_map before initializing the memory.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-18 20:54:14 +01:00
Bernhard Walle
72a7fe3967 Introduce flags for reserve_bootmem()
This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.

This patch:

Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past.  This is to avoid conflicts.

Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:25 -08:00
Yinghai Lu
6118f76fb7 x86: print out node_data addr and bootmap_start addr
print out node_data addr and bootmap_start addr.

helpful for debugging early crashes on high-end NUMA systems.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04 16:47:56 +01:00
Yinghai Lu
9347e0b0ce x86: remove unneeded round_up
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-01 17:49:42 +01:00
Yinghai Lu
24a5da73f4 x86_64: make bootmap_start page align v6
boot oopses when a system has 64 or 128 GB of RAM installed:

Calling initcall 0xffffffff80bc33b6: sctp_init+0x0/0x711()
BUG: unable to handle kernel NULL pointer dereference at 000000000000005f
IP: [<ffffffff802bfe55>] proc_register+0xe7/0x10f
PGD 0
Oops: 0000 [1] SMP
CPU 0
Modules linked in:
Pid: 1, comm: swapper Not tainted 2.6.24-smp-g5a514e21-dirty #6
RIP: 0010:[<ffffffff802bfe55>]  [<ffffffff802bfe55>] proc_register+0xe7/0x10f
RSP: 0000:ffff810824c57e60  EFLAGS: 00010246
RAX: 000000000000d7d7 RBX: ffff811024c5fa80 RCX: ffff810824c57e08
RDX: 0000000000000000 RSI: 0000000000000195 RDI: ffffffff80cc2460
RBP: ffffffffffffffff R08: 0000000000000000 R09: ffff811024c5fa80
R10: 0000000000000000 R11: 0000000000000002 R12: ffff810824c57e6c
R13: 0000000000000000 R14: ffff810824c57ee0 R15: 00000006abd25bee
FS:  0000000000000000(0000) GS:ffffffff80b4d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 000000000000005f CR3: 0000000000201000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 1, threadinfo ffff810824c56000, task ffff812024c52000)
Stack:  ffffffff80a57348 0000019500000000 ffff811024c5fa80 0000000000000000
 00000000ffffff97 ffffffff802bfef0 0000000000000000 ffffffffffffffff
 0000000000000000 ffffffff80bc3b4b ffff810824c57ee0 ffffffff80bc34a5
Call Trace:
 [<ffffffff802bfef0>] ? create_proc_entry+0x73/0x8a
 [<ffffffff80bc3b4b>] ? sctp_snmp_proc_init+0x1c/0x34
 [<ffffffff80bc34a5>] ? sctp_init+0xef/0x711
 [<ffffffff80b976e3>] ? kernel_init+0x175/0x2e1
 [<ffffffff8020ccf8>] ? child_rip+0xa/0x12
 [<ffffffff80b9756e>] ? kernel_init+0x0/0x2e1
 [<ffffffff8020ccee>] ? child_rip+0x0/0x12

Code: 1e 48 83 7b 38 00 75 08 48 c7 43 38 f0 e8 82 80 48 83 7b 30 00 75 08 48 c7 43 30 d0 e9 82 80 48 c7 c7 60 24 cc 80 e8 bd 5a 54 00 <48> 8b 45 60 48 89 6b 58 48 89 5d 60 48 89 43 50 fe 05 f5 25 a0
RIP  [<ffffffff802bfe55>] proc_register+0xe7/0x10f
 RSP <ffff810824c57e60>
CR2: 000000000000005f
---[ end trace 02c2d78def82877a ]---
Kernel panic - not syncing: Attempted to kill init!

it turns out some variables near end of bss are corrupted already.

in System.map we have
ffffffff80d40420 b rsi_table
ffffffff80d40620 B krb5_seq_lock
ffffffff80d40628 b i.20437
ffffffff80d40630 b xprt_rdma_inline_write_padding
ffffffff80d40638 b sunrpc_table_header
ffffffff80d40640 b zero
ffffffff80d40644 b min_memreg
ffffffff80d40648 b rpcrdma_tk_lock_g
ffffffff80d40650 B sctp_assocs_id_lock
ffffffff80d40658 B proc_net_sctp
ffffffff80d40660 B sctp_assocs_id
ffffffff80d40680 B sysctl_sctp_mem
ffffffff80d40690 B sysctl_sctp_rmem
ffffffff80d406a0 B sysctl_sctp_wmem
ffffffff80d406b0 b sctp_ctl_socket
ffffffff80d406b8 b sctp_pf_inet6_specific
ffffffff80d406c0 b sctp_pf_inet_specific
ffffffff80d406c8 b sctp_af_v4_specific
ffffffff80d406d0 b sctp_af_v6_specific
ffffffff80d406d8 b sctp_rand.33270
ffffffff80d406dc b sctp_memory_pressure
ffffffff80d406e0 b sctp_sockets_allocated
ffffffff80d406e4 b sctp_memory_allocated
ffffffff80d406e8 b sctp_sysctl_header
ffffffff80d406f0 b zero
ffffffff80d406f4 A __bss_stop
ffffffff80d406f4 A _end

and setup_node_bootmem() will use that page 0xd40000 for bootmap
Bootmem setup node 0 0000000000000000-0000000828000000
  NODE_DATA [000000000008a485 - 0000000000091484]
  bootmap [0000000000d406f4 -  0000000000e456f3] pages 105
Bootmem setup node 1 0000000828000000-0000001028000000
  NODE_DATA [0000000828000000 - 0000000828006fff]
  bootmap [0000000828007000 -  0000000828106fff] pages 100
Bootmem setup node 2 0000001028000000-0000001828000000
  NODE_DATA [0000001028000000 - 0000001028006fff]
  bootmap [0000001028007000 -  0000001028106fff] pages 100
Bootmem setup node 3 0000001828000000-0000002028000000
  NODE_DATA [0000001828000000 - 0000001828006fff]
  bootmap [0000001828007000 -  0000001828106fff] pages 100

setup_node_bootmem() makes NODE_DATA cacheline aligned,
and bootmap is page-aligned.

the patch updates find_e820_area() to make sure we can meet
the alignment constraints.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-01 17:49:41 +01:00
Yinghai Lu
25eff8d4cd x86_64: add debug name for early_res
helps debugging problems in this rather murky area of code.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-01 17:49:41 +01:00
Yinghai Lu
afadcd788f x86: fix nodemap_size according to nodeid bits
memnode.map is s16 array because of nodeid is 16 bit now.

so need to increase the nodemap_size according to that bits.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:34:12 +01:00
travis@sgi.com
1ce357129a x86: early cpu_to_node fix in numa_64.c
Both of these references to cpu_to_node() can potentially occur
before the "late" cpu_to_node map is setup.  Therefore, they
should be changed to use early_cpu_to_node().

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:33 +01:00
travis@sgi.com
4323838215 x86: change size of node ids from u8 to s16
Change the size of node ids for X86_64 from u8 to s16 to
accomodate more than 32k nodes and allow for NUMA_NO_NODE
(-1) to be sign extended to int.

Cc: David Rientjes <rientjes@google.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:25 +01:00
Mike Travis
625d6cffca x86: fix early cpu_to_node panic from nr_free_zone_pages
call early_cpu_to_node() since per_cpu(cpu_to_node_map) might not be setup
yet.

I also had to export x86_cpu_to_node_map_early_ptr because of some calls
from the network code to numa_node_id():

	net/ipv4/netfilter/arp_tables.c:
	net/ipv4/netfilter/ip_tables.c:
	net/ipv4/netfilter/ip_tables.c:

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
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 13:33:25 +01:00
Ingo Molnar
9c5ba48958 x86: clean up paging_init()
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:24 +01:00
Yinghai Lu
fc7250ab38 x86: only support sparsemem
sparsemem is only one supported, so could remove FLAT_NODE_MEM related,
that is only needed !SPARSEMEM

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:24 +01:00
travis@sgi.com
c49a4955ea x86: add debug of invalid per_cpu map accesses
Provide a means to trap usages of per_cpu map variables before
they are setup.  Define CONFIG_DEBUG_PER_CPU_MAPS to activate.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:22 +01:00
Andi Kleen
7517527891 x86: replace hard coded reservations in 64-bit early boot code with dynamic table
On x86-64 there are several memory allocations before bootmem. To avoid
them stomping on each other they used to be all hard coded in bad_area().
Replace this with an array that is filled as needed.

This cleans up the code considerably and allows to expand its use.

Cc: peterz@infradead.org
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:17 +01:00
travis@sgi.com
316390b093 x86: fixup NR-CPUS patch for numa
This patch removes the EXPORT_SYMBOL for:

	x86_cpu_to_node_map_init
	x86_cpu_to_node_map_early_ptr

... thus fixing the section mismatch problem.

Also, the mem -> node hash lookup is fixed.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:15 +01:00
Andrew Morton
118c890961 arch/x86/mm/numa_64.c: section fix
WARNING: vmlinux.o(__ksymtab+0x670): Section mismatch: reference to .init.data:x86_cpu_to_node_map_init (between '__ksymtab_x86_cpu_to_node_map_init' and '__ksymtab_node_data')

Cc: Matthew Dobson <colpatch@us.ibm.com>
Cc: Mike Travis <travis@sgi.com>
Cc: 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 13:33:14 +01:00
Mike Travis
693e3c5603 x86: reduce memory and intra-node effects
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:14 +01:00
travis@sgi.com
df3825c56d x86: change NR_CPUS arrays in numa_64
Change the following static arrays sized by NR_CPUS to
per_cpu data variables:

	char cpu_to_node_map[NR_CPUS];

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:11 +01:00
travis@sgi.com
3cc87e3f40 x86: change size of node ids from u8 to u16
Change the size of node ids from 8 bits to 16 bits to
accomodate more than 256 nodes.

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:11 +01:00
travis@sgi.com
ef97001f3d x86: change size of APICIDs from u8 to u16
Change the size of APICIDs from u8 to u16.  This partially
supports the new x2apic mode that will be present on future
processor chips. (Chips actually support 32-bit APICIDs, but that
change is more intrusive. Supporting 16-bit is sufficient for now).

Signed-off-by: Jack Steiner <steiner@sgi.com>

I've included just the partial change from u8 to u16 apicids.  The
remaining x2apic changes will be in a separate patch.

In addition, the fake_node_to_pxm_map[] and fake_apicid_to_node[]
tables have been moved from local data to the __initdata section
reducing stack pressure when MAX_NUMNODES and MAX_LOCAL_APIC are
increased in size.

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:10 +01:00
Yinghai Lu
a261670aed x86: cleanup setup_node_zones called by paging_init()
setup_node_zones() calcuates some variables but only use them when
FLAT_NODE_MEM_MAP is set

so change the MACRO postion to avoid calculating.

also change it to static, and rename it to flat_setup_node_zones().

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:09 +01:00
Jeremy Fitzhardinge
5548fecdff x86: clean up bitops-related warnings
Add casts to appropriate places to silence spurious bitops warnings.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:55 +01:00
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
Thomas Gleixner
7462894a7c x86: fixup numa 64 namespace
Using a variable name, which is the same as a macro name is not
really smart. Change the variable names and fixup all users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:30:38 +01:00
Thomas Gleixner
e3cfe529dd x86: cleanup numa_64.c
Clean it up before applying more patches.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:30:37 +01:00
Thomas Gleixner
3abf024d2a x86: nuke a ton of unused exports
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:30:28 +01:00
Thomas Gleixner
c9ff03428f x86: move k8 related declarations
Move k8 related declarations to k8.h and fix numa_64.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:30:16 +01:00
Mike Travis
71fff5e6ca x86: convert cpu_to_apicid to be a per cpu variable
This patch converts the x86_cpu_to_apicid array to be a per cpu
variable. This saves sizeof(apicid) * NR unused cpus.  Access is mostly
from startup and CPU HOTPLUG functions.

MP_processor_info() is one of the functions that require access to the
x86_cpu_to_apicid array before the per_cpu data area is setup.  For this
case, a pointer to the __initdata array is initialized in setup_arch()
and removed in smp_prepare_cpus() after the per_cpu data area is
initialized.

A second change is included to change the initial array value of ARCH
i386 from 0xff to BAD_APICID to be consistent with ARCH x86_64.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.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>
2007-10-19 20:35:03 +02:00
Mike Travis
98c9e27a56 x86: fix cpu_to_node references
In x86_64 and i386 architectures most arrays that are sized using
NR_CPUS lay in local memory on node 0.  Not only will most (99%?) of the
systems not use all the slots in these arrays, particularly when NR_CPUS
is increased to accommodate future very high cpu count systems, but a
number of cache lines are passed unnecessarily on the system bus when
these arrays are referenced by cpus on other nodes.

Typically, the values in these arrays are referenced by the cpu
accessing it's own values, though when passing IPI interrupts, the cpu
does access the data relevant to the targeted cpu/node.  Of course, if
the referencing cpu is not on node 0, then the reference will still
require cross node exchanges of cache lines.  A common use of this is
for an interrupt service routine to pass the interrupt to other cpus
local to that node.

Ideally, all the elements in these arrays should be moved to the per_cpu
data area.  In some cases (such as x86_cpu_to_apicid) the array is
referenced before the per_cpu data areas are setup.  In this case, a
static array is declared in the __initdata area and initialized by the
booting cpu (BSP).  The values are then moved to the per_cpu area after
it is initialized and the original static array is freed with the rest
of the __initdata.

This patch:

Fix four instances where cpu_to_node is referenced by array instead of
via the cpu_to_node macro.  This is preparation to moving it to the
per_cpu data area.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.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>
2007-10-17 20:16:37 +02:00
Yoann Padioleau
83e83d546c x86: 0 -> NULL, for arch/x86_64
When comparing a pointer, it's clearer to compare it to NULL than to 0.

[ tglx: arch/x86 adaptation ]

Signed-off-by: Yoann Padioleau <padator@wanadoo.fr>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: ak@suse.de
Cc: discuss@x86-64.org
Cc: akpm@linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-17 20:15:52 +02:00
Thomas Gleixner
95119fbd87 x86_64: move mm
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 11:17:18 +02:00
Renamed from arch/x86_64/mm/numa_64.c (Browse further)