Benjamin Herrenschmidt wrote:
On Fri, 2009-09-25 at 18:01 +0900, Tejun Heo wrote:
With this patch applied the machine boots OK :-)
Ah... so, the problem really is too high address. If you've got some
time, it might be interesting to find out how far high is safe.
Might give me a clue about what the problem is but I think I'll just
cook up a test case that forcibly vmap something high up and see how it
goes from there. It could be a very old bug that nobody ever noticed
because our vmalloc space on 64-bit is so huge :-)
I still have this problem with 2.6.32-rc3.
Here is the relevant information
0:mon> t
[link register ] c0000000001a7f78 .pcpu_alloc+0x798/0xa04
[c0000000033e37f0] c0000000001a7f08 .pcpu_alloc+0x728/0xa04 (unreliable)
[c0000000033e3920] c0000000001a8278 .__alloc_percpu+0x3c/0x58
[c0000000033e39b0] c0000000005d1ad0 .snmp_mib_init+0x64/0xb0
[c0000000033e3a40] c0000000005d1c00 .ipv4_mib_init_net+0xe4/0x1f8
[c0000000033e3b00] c00000000055b608 .setup_net+0x78/0x138
[c0000000033e3ba0] c00000000055be38 .copy_net_ns+0x9c/0x148
[c0000000033e3c30] c0000000000d06d8 .create_new_namespaces+0x120/0x1e4
[c0000000033e3ce0] c0000000000d09e0 .unshare_nsproxy_namespaces+0x7c/0xfc
[c0000000033e3d80] c00000000009dd74 .SyS_unshare+0x148/0x33c
[c0000000033e3e30] c0000000000085b4 syscall_exit+0x0/0x40
--- Exception: c01 (System Call) at 00000fff8b0ab978
SP (fffe633fe30) is in userspace
0:mon> e
cpu 0x0: Vector: 501 (Hardware Interrupt) at [c0000000033e3570]
pc: c00000000004bdc0: .memset+0x60/0xfc
lr: c0000000001a7f78: .pcpu_alloc+0x798/0xa04
sp: c0000000033e37f0
msr: 8000000000009032
current = 0xc000000003270860
paca = 0xc0000000010c2600
pid = 3442, comm = two_children_ns
0:mon> r
R00 = 0000000000000040 R07 = d00007fffff00000
R01 = c0000000033e37f0 R08 = 0000000000000000
R02 = c000000000fe7c78 R09 = c000000001700180
R03 = d00007fffff00000 R10 = c000000001095aa0
R04 = 0000000000000000 R11 = 00000000000003c0
R05 = 0000000000000000 R12 = 0000000048004428
R06 = d00007fffff00000 R13 = c0000000010c2600
pc = c00000000004bdc0 .memset+0x60/0xfc
lr = c0000000001a7f78 .pcpu_alloc+0x798/0xa04
msr = 8000000000009032 cr = 44004420
ctr = 0000000000000040 xer = 0000000020000020 trap = 501
0:mon> di $.memset
c00000000004bd60 7c0300d0 neg r0,r3
c00000000004bd64 5084442e rlwimi r4,r4,8,16,23
c00000000004bd68 70000007 andi. r0,r0,7
c00000000004bd6c 5084801e rlwimi r4,r4,16,0,15
c00000000004bd70 7c850040 cmplw cr1,r5,r0
c00000000004bd74 7884000e rldimi r4,r4,32,0
c00000000004bd78 7c101120 mtocrf 1,r0
c00000000004bd7c 7c661b78 mr r6,r3
c00000000004bd80 418400ac blt cr1,c00000000004be2c #
.memset+0xcc/0xfc
c00000000004bd84 41e2002c beq+ c00000000004bdb0 #
.memset+0x50/0xfc
c00000000004bd88 7ca02850 subf r5,r0,r5
c00000000004bd8c 409f000c bns cr7,c00000000004bd98 #
.memset+0x38/0xfc
c00000000004bd90 98860000 stb r4,0(r6)
c00000000004bd94 38c60001 addi r6,r6,1
c00000000004bd98 409e000c bne cr7,c00000000004bda4 #
.memset+0x44/0xfc
c00000000004bd9c b0860000 sth r4,0(r6)
0:mon>
c00000000004bda0 38c60002 addi r6,r6,2
c00000000004bda4 409d000c ble cr7,c00000000004bdb0 #
.memset+0x50/0xfc
c00000000004bda8 90860000 stw r4,0(r6)
c00000000004bdac 38c60004 addi r6,r6,4
c00000000004bdb0 78a0d183 rldicl. r0,r5,58,6
c00000000004bdb4 78a506a0 clrldi r5,r5,58
c00000000004bdb8 7c0903a6 mtctr r0
c00000000004bdbc 4182002c beq c00000000004bde8 #
.memset+0x88/0xfc
c00000000004bdc0 f8860000 std r4,0(r6)
At this point R06 contains d00007fffff00000.
Have attached the xmon log.
Thanks
-Sachin
--
---------------------------------
Sachin Sant
IBM Linux Technology Center
India Systems and Technology Labs
Bangalore, India
---------------------------------
0:mon> t
[link register ] c0000000001a7f78 .pcpu_alloc+0x798/0xa04
[c0000000033e37f0] c0000000001a7f08 .pcpu_alloc+0x728/0xa04 (unreliable)
[c0000000033e3920] c0000000001a8278 .__alloc_percpu+0x3c/0x58
[c0000000033e39b0] c0000000005d1ad0 .snmp_mib_init+0x64/0xb0
[c0000000033e3a40] c0000000005d1c00 .ipv4_mib_init_net+0xe4/0x1f8
[c0000000033e3b00] c00000000055b608 .setup_net+0x78/0x138
[c0000000033e3ba0] c00000000055be38 .copy_net_ns+0x9c/0x148
[c0000000033e3c30] c0000000000d06d8 .create_new_namespaces+0x120/0x1e4
[c0000000033e3ce0] c0000000000d09e0 .unshare_nsproxy_namespaces+0x7c/0xfc
[c0000000033e3d80] c00000000009dd74 .SyS_unshare+0x148/0x33c
[c0000000033e3e30] c0000000000085b4 syscall_exit+0x0/0x40
--- Exception: c01 (System Call) at 00000fff8b0ab978
SP (fffe633fe30) is in userspace
0:mon> e
cpu 0x0: Vector: 501 (Hardware Interrupt) at [c0000000033e3570]
pc: c00000000004bdc0: .memset+0x60/0xfc
lr: c0000000001a7f78: .pcpu_alloc+0x798/0xa04
sp: c0000000033e37f0
msr: 8000000000009032
current = 0xc000000003270860
paca = 0xc0000000010c2600
pid = 3442, comm = two_children_ns
0:mon> r
R00 = 0000000000000040 R07 = d00007fffff00000
R01 = c0000000033e37f0 R08 = 0000000000000000
R02 = c000000000fe7c78 R09 = c000000001700180
R03 = d00007fffff00000 R10 = c000000001095aa0
R04 = 0000000000000000 R11 = 00000000000003c0
R05 = 0000000000000000 R12 = 0000000048004428
R06 = d00007fffff00000 R13 = c0000000010c2600
pc = c00000000004bdc0 .memset+0x60/0xfc
lr = c0000000001a7f78 .pcpu_alloc+0x798/0xa04
msr = 8000000000009032 cr = 44004420
ctr = 0000000000000040 xer = 0000000020000020 trap = 501
0:mon> di $.memset
c00000000004bd60 7c0300d0 neg r0,r3
c00000000004bd64 5084442e rlwimi r4,r4,8,16,23
c00000000004bd68 70000007 andi. r0,r0,7
c00000000004bd6c 5084801e rlwimi r4,r4,16,0,15
c00000000004bd70 7c850040 cmplw cr1,r5,r0
c00000000004bd74 7884000e rldimi r4,r4,32,0
c00000000004bd78 7c101120 mtocrf 1,r0
c00000000004bd7c 7c661b78 mr r6,r3
c00000000004bd80 418400ac blt cr1,c00000000004be2c #
.memset+0xcc/0xfc
c00000000004bd84 41e2002c beq+ c00000000004bdb0 #
.memset+0x50/0xfc
c00000000004bd88 7ca02850 subf r5,r0,r5
c00000000004bd8c 409f000c bns cr7,c00000000004bd98 #
.memset+0x38/0xfc
c00000000004bd90 98860000 stb r4,0(r6)
c00000000004bd94 38c60001 addi r6,r6,1
c00000000004bd98 409e000c bne cr7,c00000000004bda4 #
.memset+0x44/0xfc
c00000000004bd9c b0860000 sth r4,0(r6)
0:mon>
c00000000004bda0 38c60002 addi r6,r6,2
c00000000004bda4 409d000c ble cr7,c00000000004bdb0 #
.memset+0x50/0xfc
c00000000004bda8 90860000 stw r4,0(r6)
c00000000004bdac 38c60004 addi r6,r6,4
c00000000004bdb0 78a0d183 rldicl. r0,r5,58,6
c00000000004bdb4 78a506a0 clrldi r5,r5,58
c00000000004bdb8 7c0903a6 mtctr r0
c00000000004bdbc 4182002c beq c00000000004bde8 #
.memset+0x88/0xfc
c00000000004bdc0 f8860000 std r4,0(r6)
c00000000004bdc4 f8860008 std r4,8(r6)
c00000000004bdc8 f8860010 std r4,16(r6)
c00000000004bdcc f8860018 std r4,24(r6)
c00000000004bdd0 f8860020 std r4,32(r6)
c00000000004bdd4 f8860028 std r4,40(r6)
c00000000004bdd8 f8860030 std r4,48(r6)
c00000000004bddc f8860038 std r4,56(r6)
0:mon> u
SLB contents of cpu 0
00 c000000008000000 40004f7ca3000500 1T ESID= c00000 VSID= 4f7ca3
LLP:100
01 d000000008000000 4000eb71b0000510 1T ESID= d00000 VSID= eb71b0
LLP:110
20 f000000008000000 4000235bcc000500 1T ESID= f00000 VSID= 235bcc
LLP:100
27 00000f0008000000 400014e596000d90 1T ESID= f VSID= 14e596
LLP:110
28 0000000018000000 00004be47e859d90 256M ESID= 1 VSID= 4be47e859
LLP:110
29 d000070008000000 400026a7a5000400 1T ESID= d00007 VSID= 26a7a5
LLP: 0
30 d000080008000000 4000e5f87e000400 1T ESID= d00008 VSID= e5f87e
LLP: 0
0:mon> S
msr = 8000000000001032 sprg0= 0000000000000000
pvr = 00000000003e0301 sprg1= c0000000010c2600
dec = 0000000058fe12dd sprg2= c0000000010c2600
sp = c00000000fffb8f0 sprg3= 0000000000000000
toc = c000000000fe7c78 dar = d00007fffff00000
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
