"slub: Rework allocator fastpaths" and slub debugging
From: Rabin Vincent
Date: Thu Jul 21 2011 - 14:45:02 EST
Enabling slub debugging on linux-next throws up continuous apparently
spurious "Redzone overwritten" reports, right from startup. The start
of a boot log is below (the rest of the log has more such reports).
Bisecting points to the following commit:
commit 2cfb7455d223ab24b23df44be430faf92e12390f
Author: Christoph Lameter <cl@xxxxxxxxx>
Date: Wed Jun 1 12:25:52 2011 -0500
slub: Rework allocator fastpaths
Rework the allocation paths so that updates of the page freelist, frozen
state and number of objects use cmpxchg_double_slab().
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxx>
Thanks.
Uncompressing Linux... done, booting the kernel.
[ 0.000000] Linux version 3.0.0-rc7-next-20110721 (rabin@debian) (gcc version 4.6.0 (crosstool-NG-hg_default@2404_8988576c491a) ) #288 PREEMPT Fri Jul 22 00:07:05 IST 2011
[ 0.000000] CPU: ARMv7 Processor [410fc090] revision 0 (ARMv7), cr=10c53c7f
[ 0.000000] CPU: VIPT nonaliasing data cache, VIPT aliasing instruction cache
[ 0.000000] Machine: ARM-RealView PBX
[ 0.000000] Ignoring unrecognised tag 0x00000000
[ 0.000000] bootconsole [earlycon0] enabled
[ 0.000000] Memory policy: ECC disabled, Data cache writeback
[ 0.000000] On node 0 totalpages: 32768
[ 0.000000] DMA zone: 256 pages used for memmap
[ 0.000000] DMA zone: 0 pages reserved
[ 0.000000] DMA zone: 32512 pages, LIFO batch:7
[ 0.000000] sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 178956ms
[ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[ 0.000000] pcpu-alloc: [0] 0
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 32512
[ 0.000000] Kernel command line: earlyprintk console=ttyAMA0 mem=128M debug slub_debug
[ 0.000000] PID hash table entries: 512 (order: -1, 2048 bytes)
[ 0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
[ 0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
[ 0.000000] Memory: 128MB = 128MB total
[ 0.000000] Memory: 128208k/128208k available, 2864k reserved, 0K highmem
[ 0.000000] Virtual kernel memory layout:
[ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB)
[ 0.000000] fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB)
[ 0.000000] DMA : 0xffc00000 - 0xffe00000 ( 2 MB)
[ 0.000000] vmalloc : 0xc8800000 - 0xf8000000 ( 760 MB)
[ 0.000000] lowmem : 0xc0000000 - 0xc8000000 ( 128 MB)
[ 0.000000] modules : 0xbf000000 - 0xc0000000 ( 16 MB)
[ 0.000000] .text : 0xc0008000 - 0xc0167000 (1404 kB)
[ 0.000000] .init : 0xc0167000 - 0xc017b000 ( 80 kB)
[ 0.000000] .data : 0xc017c000 - 0xc018e5a0 ( 74 kB)
[ 0.000000] .bss : 0xc018e5c4 - 0xc01981fc ( 40 kB)
[ 0.000000] SLUB: Genslabs=13, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[ 0.000000] Preemptible hierarchical RCU implementation.
[ 0.000000] Verbose stalled-CPUs detection is disabled.
[ 0.000000] NR_IRQS:128
[ 0.000000] Console: colour dummy device 80x30
[ 0.025412] Calibrating delay loop... 430.08 BogoMIPS (lpj=2150400)
[ 0.213437] pid_max: default: 32768 minimum: 301
[ 0.214891] Mount-cache hash table entries: 512
[ 0.221089] CPU: Testing write buffer coherency: ok
[ 0.230143] =============================================================================
[ 0.230365] BUG idr_layer_cache: Redzone overwritten
[ 0.230478] -----------------------------------------------------------------------------
[ 0.230501]
[ 0.230700] INFO: 0xc7820c94-0xc7820c97. First byte 0xbb instead of 0xcc
[ 0.230974] INFO: Slab 0xc0289400 objects=21 used=21 fp=0x (null) flags=0x0080
[ 0.231145] INFO: Object 0xc7820c00 @offset=3072 fp=0xc7820cc0
[ 0.231162]
[ 0.231370] Bytes b4 0xc7820bf0: 00 00 00 00 00 00 00 00 00 00 00 00 5a 5a 5a 5a ............ZZZZ
[ 0.231722] Object 0xc7820c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.232012] Object 0xc7820c10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.232301] Object 0xc7820c20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.232644] Object 0xc7820c30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.232931] Object 0xc7820c40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.233218] Object 0xc7820c50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.233571] Object 0xc7820c60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.233889] Object 0xc7820c70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.234186] Object 0xc7820c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.234484] Object 0xc7820c90: 00 00 00 00 ....
[ 0.234802] Redzone 0xc7820c94: bb bb bb bb »»»»
[ 0.235101] Padding 0xc7820cbc: 5a 5a 5a 5a ZZZZ
[ 0.235417] Backtrace:
[ 0.235979] [<c00106dc>] (dump_backtrace+0x0/0x110) from [<c012a88c>] (dump_stack+0x18/0x1c)
[ 0.236222] r6:c7820010 r5:c7820c00 r4:c7803000 r3:00000000
[ 0.236429] [<c012a874>] (dump_stack+0x0/0x1c) from [<c007d790>] (print_trailer+0x1a4/0x1c0)
[ 0.236633] [<c007d5ec>] (print_trailer+0x0/0x1c0) from [<c007dbb0>] (check_bytes_and_report+0xa4/0xd4)
[ 0.236829] r7:000000cc r6:c7803000 r5:c7820c94 r4:c7820c98
[ 0.237007] [<c007db0c>] (check_bytes_and_report+0x0/0xd4) from [<c007dc30>] (check_object+0x50/0x2c0)
[ 0.237222] [<c007dbe0>] (check_object+0x0/0x2c0) from [<c012b980>] (free_debug_processing+0x174/0x2ac)
[ 0.237418] r8:c00e43f0 r7:20000013 r6:c7803000 r5:c7820c00 r4:c0289400
[ 0.237624] [<c012b80c>] (free_debug_processing+0x0/0x2ac) from [<c012baec>] (__slab_free+0x34/0x28c)
[ 0.237816] r8:c7820c00 r7:00000083 r6:c7803000 r5:80050d00 r4:c0289400
[ 0.237992] r3:c00e43f0
[ 0.238085] [<c012bab8>] (__slab_free+0x0/0x28c) from [<c007f648>] (kmem_cache_free+0xe8/0xf0)
[ 0.238288] [<c007f560>] (kmem_cache_free+0x0/0xf0) from [<c00e43f0>] (ida_get_new_above+0x1c8/0x1e8)
[ 0.238480] r8:00000002 r7:c0196564 r6:c782a000 r5:00000000 r4:c780d240
[ 0.238657] r3:c0196a3c
[ 0.238751] [<c00e4228>] (ida_get_new_above+0x0/0x1e8) from [<c00caf6c>] (sysfs_new_dirent+0x7c/0x114)
[ 0.238966] [<c00caef0>] (sysfs_new_dirent+0x0/0x114) from [<c00cb46c>] (create_dir+0x30/0xb4)
[ 0.239167] [<c00cb43c>] (create_dir+0x0/0xb4) from [<c00cb648>] (sysfs_create_dir+0xb0/0xc8)
[ 0.239362] r8:00000000 r7:00000000 r6:c01890d0 r5:00000000 r4:c7821388
[ 0.239569] [<c00cb598>] (sysfs_create_dir+0x0/0xc8) from [<c00e4bec>] (kobject_add_internal+0xf4/0x1d0)
[ 0.239766] r6:00000000 r5:c7821388 r4:c013c4d0
[ 0.239916] [<c00e4af8>] (kobject_add_internal+0x0/0x1d0) from [<c00e51ac>] (kset_register+0x28/0x44)
[ 0.240107] r8:00000000 r7:00000000 r6:c7821380 r5:c7821388 r4:c013c4d0
[ 0.240283] r3:c01898fc
[ 0.240377] [<c00e5184>] (kset_register+0x0/0x44) from [<c00e5370>] (kset_create_and_add+0x80/0xa4)
[ 0.240565] r5:00000000 r4:c013c4d0
[ 0.240723] [<c00e52f0>] (kset_create_and_add+0x0/0xa4) from [<c0175abc>] (devices_init+0x1c/0xbc)
[ 0.240911] r7:00000013 r6:c0021054 r5:c017a700 r4:c017a55c
[ 0.241089] [<c0175aa0>] (devices_init+0x0/0xbc) from [<c01762cc>] (driver_init+0x10/0x2c)
[ 0.241264] r4:c017a55c r3:00000000
[ 0.241381] [<c01762bc>] (driver_init+0x0/0x2c) from [<c0167ab4>] (kernel_init+0x6c/0x118)
[ 0.241577] [<c0167a48>] (kernel_init+0x0/0x118) from [<c0021054>] (do_exit+0x0/0x6a8)
[ 0.241745] r5:c0167a48 r4:00000000
[ 0.241914] FIX idr_layer_cache: Restoring 0xc7820c94-0xc7820c97=0xcc
[ 0.241934]
[ 0.242790] =============================================================================
[ 0.242989] BUG idr_layer_cache: Redzone overwritten
[ 0.243099] -----------------------------------------------------------------------------
[ 0.243121]
[ 0.243382] INFO: 0xc7820bd4-0xc7820bd7. First byte 0xbb instead of 0xcc
[ 0.243550] INFO: Slab 0xc0289400 objects=21 used=21 fp=0x (null) flags=0x0080
[ 0.243711] INFO: Object 0xc7820b40 @offset=2880 fp=0xc7820c00
[ 0.243729]
[ 0.243874] Bytes b4 0xc7820b30: 00 00 00 00 00 00 00 00 00 00 00 00 5a 5a 5a 5a ............ZZZZ
[ 0.244177] Object 0xc7820b40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.244496] Object 0xc7820b50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.244796] Object 0xc7820b60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.245096] Object 0xc7820b70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.245397] Object 0xc7820b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.245697] Object 0xc7820b90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.245998] Object 0xc7820ba0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.246299] Object 0xc7820bb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.246599] Object 0xc7820bc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 0.246899] Object 0xc7820bd0: 00 00 00 00 ....
[ 0.247181] Redzone 0xc7820bd4: bb bb bb bb »»»»
[ 0.247470] Padding 0xc7820bfc: 5a 5a 5a 5a ZZZZ
[ 0.247750] Backtrace:
[ 0.247852] [<c00106dc>] (dump_backtrace+0x0/0x110) from [<c012a88c>] (dump_stack+0x18/0x1c)
[ 0.248033] r6:c7820010 r5:c7820b40 r4:c7803000 r3:00000000
[ 0.248211] [<c012a874>] (dump_stack+0x0/0x1c) from [<c007d790>] (print_trailer+0x1a4/0x1c0)
[ 0.248411] [<c007d5ec>] (print_trailer+0x0/0x1c0) from [<c007dbb0>] (check_bytes_and_report+0xa4/0xd4)
[ 0.248607] r7:000000cc r6:c7803000 r5:c7820bd4 r4:c7820bd8
[ 0.248787] [<c007db0c>] (check_bytes_and_report+0x0/0xd4) from [<c007dc30>] (check_object+0x50/0x2c0)
[ 0.249002] [<c007dbe0>] (check_object+0x0/0x2c0) from [<c012b980>] (free_debug_processing+0x174/0x2ac)
[ 0.249260] r8:c00e43f0 r7:20000013 r6:c7803000 r5:c7820b40 r4:c0289400
[ 0.249469] [<c012b80c>] (free_debug_processing+0x0/0x2ac) from [<c012baec>] (__slab_free+0x34/0x28c)
[ 0.249664] r8:c7820b40 r7:00000083 r6:c7803000 r5:80050d00 r4:c0289400
[ 0.249840] r3:c00e43f0
[ 0.249934] [<c012bab8>] (__slab_free+0x0/0x28c) from [<c007f648>] (kmem_cache_free+0xe8/0xf0)
[ 0.250139] [<c007f560>] (kmem_cache_free+0x0/0xf0) from [<c00e43f0>] (ida_get_new_above+0x1c8/0x1e8)
[ 0.250331] r8:00000002 r7:c0196564 r6:c782a000 r5:00000000 r4:c780d240
[ 0.250508] r3:c0196a3c
[ 0.250603] [<c00e4228>] (ida_get_new_above+0x0/0x1e8) from [<c00caf6c>] (sysfs_new_dirent+0x7c/0x114)
[ 0.250816] [<c00caef0>] (sysfs_new_dirent+0x0/0x114) from [<c00cb46c>] (create_dir+0x30/0xb4)
[ 0.251015] [<c00cb43c>] (create_dir+0x0/0xb4) from [<c00cb648>] (sysfs_create_dir+0xb0/0xc8)
[ 0.251193] r8:00000000 r7:00000013 r6:c01890d0 r5:00000000 r4:c7821400
[ 0.251409] [<c00cb598>] (sysfs_create_dir+0x0/0xc8) from [<c00e4bec>] (kobject_add_internal+0xf4/0x1d0)
[ 0.251605] r6:00000000 r5:c7821400 r4:c7821400
[ 0.251755] [<c00e4af8>] (kobject_add_internal+0x0/0x1d0) from [<c00e4da4>] (kobject_add+0x74/0x94)
[ 0.251942] r8:00000000 r7:00000013 r6:00000000 r5:00000000 r4:c7821400
[ 0.252115] r3:00000000
[ 0.252210] [<c00e4d30>] (kobject_add+0x0/0x94) from [<c00e5108>] (kobject_create_and_add+0x30/0x64)
[ 0.252401] r3:c015a4d0 r2:c015d711
[ 0.252499] r6:00000000 r5:c015a4d0 r4:c7821400
[ 0.252650] [<c00e50d8>] (kobject_create_and_add+0x0/0x64) from [<c0175ad8>] (devices_init+0x38/0xbc)
[ 0.252842] r6:c0021054 r5:c017a700 r4:c0198174 r3:00000000
[ 0.253018] [<c0175aa0>] (devices_init+0x0/0xbc) from [<c01762cc>] (driver_init+0x10/0x2c)
[ 0.253191] r4:c017a55c r3:00000000
[ 0.253324] [<c01762bc>] (driver_init+0x0/0x2c) from [<c0167ab4>] (kernel_init+0x6c/0x118)
[ 0.253530] [<c0167a48>] (kernel_init+0x0/0x118) from [<c0021054>] (do_exit+0x0/0x6a8)
[ 0.253698] r5:c0167a48 r4:00000000
[ 0.253806] FIX idr_layer_cache: Restoring 0xc7820bd4-0xc7820bd7=0xcc
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/