12:56 a.m.
Hi Joonsoo,
0day kernel testing robot got the below dmesg and the first bad commit is
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
commit 36fbfebe776eb5871d61e7a755c9feb1c96cc4aa
Author: Joonsoo Kim <iamjoonsoo.kim(a)lge.com>
AuthorDate: Tue Sep 23 11:52:35 2014 +1000
Commit: Stephen Rothwell <sfr(a)canb.auug.org.au>
CommitDate: Tue Sep 23 11:52:35 2014 +1000
mm/slab: support slab merge
Slab merge is good feature to reduce fragmentation. If new creating slab
have similar size and property with exsitent slab, this feature reuse it
rather than creating new one. As a result, objects are packed into fewer
slabs so that fragmentation is reduced.
Below is result of my testing.
* After boot, sleep 20; cat /proc/meminfo | grep Slab
<Before>
Slab: 25136 kB
<After>
Slab: 24364 kB
We can save 3% memory used by slab.
For supporting this feature in SLAB, we need to implement SLAB specific
kmem_cache_flag() and __kmem_cache_alias(), because SLUB implements some
SLUB specific processing related to debug flag and object size change on
these functions.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim(a)lge.com>
Cc: Christoph Lameter <cl(a)linux.com>
Cc: Pekka Enberg <penberg(a)kernel.org>
Cc: David Rientjes <rientjes(a)google.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
+----------------------------------------------+------------+------------+---------------+
| | 8c087489b8 | 36fbfebe77 | next-20140923
|
+----------------------------------------------+------------+------------+---------------+
| boot_successes | 60 | 0 | 1
|
| boot_failures | 0 | 20 | 314
|
| BUG:unable_to_handle_kernel | 0 | 20 | 312
|
| Oops | 0 | 20 | 312
|
| EIP_is_at_kernfs_link_sibling | 0 | 4 | 14
|
| Kernel_panic-not_syncing:Fatal_exception | 0 | 20 | 312
|
| backtrace:acpi_bus_scan | 0 | 4 | 14
|
| backtrace:acpi_scan_init | 0 | 20 | 45
|
| backtrace:acpi_init | 0 | 20 | 45
|
| backtrace:kernel_init_freeable | 0 | 20 | 312
|
| EIP_is_at_kernfs_add_one | 0 | 16 | 298
|
| backtrace:kobject_add_internal | 0 | 16 | 31
|
| backtrace:kobject_init_and_add | 0 | 16 | 31
|
| backtrace:acpi_scan_add_handler_with_hotplug | 0 | 16 | 31
|
| backtrace:acpi_pci_root_init | 0 | 16 | 31
|
| backtrace:tty_register_driver | 0 | 0 | 106
|
| backtrace:pty_init | 0 | 0 | 106
|
| backtrace:acpi_bus_register_driver | 0 | 0 | 1
|
| backtrace:acpi_button_driver_init | 0 | 0 | 1
|
| BUG:kernel_boot_crashed | 0 | 0 | 1
|
| BUG:kernel_test_crashed | 0 | 0 | 1
|
| backtrace:subsys_system_register | 0 | 0 | 160
|
| backtrace:container_dev_init | 0 | 0 | 160
|
| backtrace:driver_init | 0 | 0 | 160
|
+----------------------------------------------+------------+------------+---------------+
[ 0.463788] ACPI: (supports S0 S5)
[ 0.464003] ACPI: Using IOAPIC for interrupt routing
[ 0.464738] PCI: Using host bridge windows from ACPI; if necessary, use
"pci=nocrs" and report a bug
[ 0.466034] BUG: unable to handle kernel paging request at 00010023
[ 0.466989] IP: [<c117dcf9>] kernfs_add_one+0x89/0x130
[ 0.467812] *pdpt = 0000000000000000 *pde = f000ff53f000ff53
[ 0.468000] Oops: 0002 [#1] SMP
[ 0.468000] Modules linked in:
[ 0.468000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc6-00089-g36fbfeb #1
[ 0.468000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.468000] task: d303ec90 ti: d3040000 task.ti: d3040000
[ 0.468000] EIP: 0060:[<c117dcf9>] EFLAGS: 00010286 CPU: 0
[ 0.468000] EIP is at kernfs_add_one+0x89/0x130
[ 0.468000] EAX: 542572cb EBX: 00010003 ECX: 00000008 EDX: 2c8de598
[ 0.468000] ESI: d311de10 EDI: d311de70 EBP: d3041dd8 ESP: d3041db4
[ 0.468000] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[ 0.468000] CR0: 8005003b CR2: 00010023 CR3: 01a8a000 CR4: 000006f0
[ 0.468000] Stack:
[ 0.468000] d3006f00 00000202 d311de70 d311de10 d3041dd8 c117dba0 d311de10 c159a5c0
[ 0.468000] c1862a00 d3041df0 c117f0f2 00000000 c18629f4 d311de70 00000000 d3041e2c
[ 0.468000] c117f8b5 00001000 00000000 c159a5c0 c18629f4 00000000 00000001 c1862a00
[ 0.468000] Call Trace:
[ 0.468000] [<c117dba0>] ? kernfs_new_node+0x30/0x40
[ 0.468000] [<c117f0f2>] __kernfs_create_file+0x92/0xc0
[ 0.468000] [<c117f8b5>] sysfs_add_file_mode_ns+0x95/0x190
[ 0.468000] [<c117f9d7>] sysfs_create_file_ns+0x27/0x40
[ 0.468000] [<c1252ef6>] kobject_add_internal+0x136/0x2c0
[ 0.468000] [<c125e360>] ? kvasprintf+0x40/0x50
[ 0.468000] [<c1252a92>] ? kobject_set_name_vargs+0x42/0x60
[ 0.468000] [<c12530b5>] kobject_init_and_add+0x35/0x50
[ 0.468000] [<c12ad04f>] acpi_sysfs_add_hotplug_profile+0x24/0x4a
[ 0.468000] [<c12a7280>] acpi_scan_add_handler_with_hotplug+0x21/0x28
[ 0.468000] [<c18df524>] acpi_pci_root_init+0x20/0x22
[ 0.468000] [<c18df0e1>] acpi_scan_init+0x24/0x16d
[ 0.468000] [<c18def73>] acpi_init+0x20c/0x224
[ 0.468000] [<c18ded67>] ? acpi_sleep_init+0xab/0xab
[ 0.468000] [<c100041e>] do_one_initcall+0x7e/0x1b0
[ 0.468000] [<c18ded67>] ? acpi_sleep_init+0xab/0xab
[ 0.468000] [<c18b24ba>] ? repair_env_string+0x12/0x54
[ 0.468000] [<c18b24a8>] ? initcall_blacklist+0x7c/0x7c
[ 0.468000] [<c105e100>] ? parse_args+0x160/0x3f0
[ 0.468000] [<c18b2bd1>] kernel_init_freeable+0xfc/0x179
[ 0.468000] [<c156782b>] kernel_init+0xb/0xd0
[ 0.468000] [<c1574601>] ret_from_kernel_thread+0x21/0x30
[ 0.468000] [<c1567820>] ? rest_init+0xb0/0xb0
[ 0.468000] Code: 26 00 83 e1 10 75 5b 8b 46 24 e8 b3 ea ff ff 89 46 38 89 f0 e8 d9 f9
ff ff 85 c0 89 c3 75 ca 8b 5f 5c 85 db 74 11 e8 97 90 f1 ff <89> 43 20 89 53 24 89
43 28 89 53 2c b8 c0 2f 85 c1 e8 d1 36 3f
[ 0.468000] EIP: [<c117dcf9>] kernfs_add_one+0x89/0x130 SS:ESP 0068:d3041db4
[ 0.468000] CR2: 0000000000010023
[ 0.468000] ---[ end trace 4fa173691404b63f ]---
[ 0.468000] Kernel panic - not syncing: Fatal exception
git bisect start 55f21306900abf9f9d2a087a127ff49c6d388ad2
0f33be009b89d2268e94194dc4fd01a7851b6d51 --
git bisect good 18c13e2d9b75e2760e6520f2fde00401192956f3 # 17:56 20+ 0 Merge
remote-tracking branch 'bluetooth/master'
git bisect good abf79495f38ba66f750566b3f0a8da8dd94b4dc3 # 18:03 20+ 0 Merge
remote-tracking branch 'ftrace/for-next'
git bisect good 0bed22034e26a3c37ee4407fccffa8c095d5e144 # 18:09 20+ 0 Merge
remote-tracking branch 'pinctrl/for-next'
git bisect good 15c9281a15ed7718868d115d4d00619b0b7a2624 # 18:14 20+ 0 Merge
remote-tracking branch 'clk/clk-next'
git bisect good 50939531dea1b913b7fa29f9bbc69feafefd090c # 18:23 20+ 0 Merge
branch 'rd-docs/master'
git bisect good aa881e3c5e87c8aa23519f40554897d56f32b935 # 18:49 20+ 0 Merge
remote-tracking branch 'powerpc-mpe/next'
git bisect bad 81b63d14db32bd7706c955d1e04e65b152b2277a # 18:57 0- 2 Merge
branch 'akpm-current/current'
git bisect bad f313ca82d72066a3c44fd6c66cee57b25de43aa9 # 19:31 0- 1
introduce-dump_vma-fix
git bisect good 2c5fe9213048c5640b8e46407f5614038c03ad93 # 20:16 20+ 0 mm: fix
kmemcheck.c build errors
git bisect bad 69454f8be7f621ac8c3c6c9763bb70e116988942 # 20:35 0- 18
block_dev: implement readpages() to optimize sequential read
git bisect bad 66a31d528a1e3d483be2b1c993ec1268412f0074 # 20:40 0- 1
memory-hotplug-add-sysfs-zones_online_to-attribute-fix-2
git bisect good 5e8acb68610c077b08cb3f16305aa3cc22e5d2a8 # 21:07 20+ 0
kernel/kthread.c: partial revert of 81c98869faa5 ("kthread: ensure locality of
task_struct allocations")
git bisect bad 36fbfebe776eb5871d61e7a755c9feb1c96cc4aa # 22:06 0- 10 mm/slab:
support slab merge
git bisect good 11e57381eced875ef5a6fea4005fdf72b6f68eff # 22:19 20+ 0
mm/slab_common: commonize slab merge logic
git bisect good 8c087489b8a32b9235f7f9417390c62d93aba522 # 22:24 20+ 0
mm/slab_common: fix build failure if CONFIG_SLUB
# first bad commit: [36fbfebe776eb5871d61e7a755c9feb1c96cc4aa] mm/slab: support slab
merge
git bisect good 8c087489b8a32b9235f7f9417390c62d93aba522 # 22:26 60+ 0
mm/slab_common: fix build failure if CONFIG_SLUB
git bisect bad 55f21306900abf9f9d2a087a127ff49c6d388ad2 # 22:26 0- 314 Add
linux-next specific files for 20140923
git bisect good f4cb707e7ad9727a046b463232f2de166e327d3e # 22:32 60+ 0 Merge
tag 'pm+acpi-3.17-rc7' of
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
git bisect bad 4d8426f9ac601db2a64fa7be64051d02b9c9fe01 # 22:36 0- 60 Add
linux-next specific files for 20140926
This script may reproduce the error.
----------------------------------------------------------------------------
#!/bin/bash
kernel=$1
kvm=(
qemu-system-x86_64
-cpu kvm64
-enable-kvm
-kernel $kernel
-m 320
-smp 1
-net nic,vlan=1,model=e1000
-net user,vlan=1
-boot order=nc
-no-reboot
-watchdog i6300esb
-rtc base=localtime
-serial stdio
-display none
-monitor null
)
append=(
hung_task_panic=1
earlyprintk=ttyS0,115200
debug
apic=debug
sysrq_always_enabled
rcupdate.rcu_cpu_stall_timeout=100
panic=-1
softlockup_panic=1
nmi_watchdog=panic
oops=panic
load_ramdisk=2
prompt_ramdisk=0
console=ttyS0,115200
console=tty0
vga=normal
root=/dev/ram0
rw
drbd.minor_count=8
)
"${kvm[@]}" --append "${append[*]}"
----------------------------------------------------------------------------
Thanks,
Fengguang
_______________________________________________
LKP mailing list
LKP(a)linux.intel.com
1:21 a.m.
New subject: [mm/slab] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/cpu/common.c:1430 warn_pre_alternatives()
Hi Joonsoo,
0day kernel testing robot got the below dmesg and the first bad commit is
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
commit 8d8590d51e2b169f327a74c032333368f7f97f97
Author: Joonsoo Kim <iamjoonsoo.kim(a)lge.com>
AuthorDate: Fri Sep 26 10:18:56 2014 +1000
Commit: Stephen Rothwell <sfr(a)canb.auug.org.au>
CommitDate: Fri Sep 26 10:18:56 2014 +1000
mm/slab: support slab merge
Slab merge is good feature to reduce fragmentation. If new creating slab
have similar size and property with exsitent slab, this feature reuse it
rather than creating new one. As a result, objects are packed into fewer
slabs so that fragmentation is reduced.
Below is result of my testing.
* After boot, sleep 20; cat /proc/meminfo | grep Slab
<Before>
Slab: 25136 kB
<After>
Slab: 24364 kB
We can save 3% memory used by slab.
For supporting this feature in SLAB, we need to implement SLAB specific
kmem_cache_flag() and __kmem_cache_alias(), because SLUB implements some
SLUB specific processing related to debug flag and object size change on
these functions.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim(a)lge.com>
Cc: Christoph Lameter <cl(a)linux.com>
Cc: Pekka Enberg <penberg(a)kernel.org>
Cc: David Rientjes <rientjes(a)google.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
+-----------------------------------------------------------------+------------+------------+---------------+
| | f49e433b66 |
8d8590d51e | next-20140926 |
+-----------------------------------------------------------------+------------+------------+---------------+
| boot_successes | 60 | 0
| 0 |
| boot_failures | 0 | 20
| 11 |
| WARNING:at_arch/x86/kernel/cpu/common.c:warn_pre_alternatives() | 0 | 20
| |
| BUG:unable_to_handle_kernel | 0 | 20
| 11 |
| Oops | 0 | 20
| 11 |
| EIP_is_at_kernfs_add_one | 0 | 20
| |
| Kernel_panic-not_syncing:Fatal_exception | 0 | 20
| 11 |
| backtrace:kobject_create_and_add | 0 | 20
| |
| backtrace:mnt_init | 0 | 20
| |
| backtrace:vfs_caches_init | 0 | 20
| |
| EIP_is_at_kernfs_put | 0 | 0
| 11 |
| backtrace:sysfs_remove_group | 0 | 0
| 11 |
| backtrace:param_sysfs_init | 0 | 0
| 11 |
| backtrace:kernel_init_freeable | 0 | 0
| 11 |
+-----------------------------------------------------------------+------------+------------+---------------+
[ 0.060070] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.064160] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.070024] ------------[ cut here ]------------
[ 0.072984] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/cpu/common.c:1430
warn_pre_alternatives+0x30/0x40()
[ 0.079331] You're using static_cpu_has before alternatives have run!
[ 0.080000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-rc6-00222-g8d8590d #2
[ 0.080000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.7.5-20140531_083030-gandalf 04/01/2014
[ 0.080000] c21022f8 c21cdd64 c1d3c98c c21cdd98 c1070636 c2102348 c21cddc4 00000000
[ 0.080000] c21022f8 00000596 c1020830 00000596 c1020830 43a81621 c21cde6c c1057f20
[ 0.080000] c21cddb0 c107072a 00000009 c21cdda8 c2102348 c21cddc4 c21cddc4 c1020830
[ 0.080000] Call Trace:
[ 0.080000] [<c1d3c98c>] dump_stack+0x40/0x5e
[ 0.080000] [<c1070636>] warn_slowpath_common+0xb6/0x100
[ 0.080000] [<c1020830>] ? warn_pre_alternatives+0x30/0x40
[ 0.080000] [<c1020830>] ? warn_pre_alternatives+0x30/0x40
[ 0.080000] [<c1057f20>] ? kvm_read_and_reset_pf_reason+0x40/0x40
[ 0.080000] [<c107072a>] warn_slowpath_fmt+0x4a/0x60
[ 0.080000] [<c1020830>] warn_pre_alternatives+0x30/0x40
[ 0.080000] [<c105d8a3>] __do_page_fault+0x153/0xa80
[ 0.080000] [<c105873f>] ? kvm_clock_read+0x2f/0x60
[ 0.080000] [<c1010067>] ? sched_clock+0x17/0x30
[ 0.080000] [<c1057f20>] ? kvm_read_and_reset_pf_reason+0x40/0x40
[ 0.080000] [<c105e5d6>] do_page_fault+0x36/0x50
[ 0.080000] [<c1057f40>] do_async_page_fault+0x20/0xf0
[ 0.080000] [<c1d53b3d>] error_code+0x65/0x6c
[ 0.080000] [<c1270000>] ? proc_pid_status+0x620/0xff0
[ 0.080000] [<c127a139>] ? kernfs_add_one+0x119/0x270
[ 0.080000] [<c1279bb7>] ? kernfs_new_node+0x67/0x90
[ 0.080000] [<c127a2fa>] kernfs_create_dir_ns+0x6a/0xc0
[ 0.080000] [<c127e036>] sysfs_create_dir_ns+0x56/0x120
[ 0.080000] [<c141986a>] kobject_add_internal+0x20a/0x870
[ 0.080000] [<c1432de6>] ? kvasprintf+0x86/0xa0
[ 0.080000] [<c141a153>] kobject_add_varg+0x43/0x90
[ 0.080000] [<c141a240>] kobject_add+0x40/0xb0
[ 0.080000] [<c14192f5>] ? kobject_create+0xf5/0x110
[ 0.080000] [<c141a30a>] kobject_create_and_add+0x5a/0xd0
[ 0.080000] [<c2551bc9>] mnt_init+0x1e4/0x380
[ 0.080000] [<c25511b5>] ? files_init+0x2c/0x7c
[ 0.080000] [<c255156f>] vfs_caches_init+0xe2/0x1b3
[ 0.080000] [<c25585de>] ? integrity_iintcache_init+0x2c/0x4d
[ 0.080000] [<c13d0b90>] ? devcgroup_inode_mknod+0x90/0x90
[ 0.080000] [<c251d6a3>] start_kernel+0x8cf/0x97d
[ 0.080000] [<c251c33b>] i386_start_kernel+0xe9/0xfb
[ 0.080000] ---[ end trace 8c750c6fe159171a ]---
[ 0.080000] BUG: unable to handle kernel paging request at 43a81621
git bisect start 4d8426f9ac601db2a64fa7be64051d02b9c9fe01
0f33be009b89d2268e94194dc4fd01a7851b6d51 --
git bisect good deb2ffc8689a85df3c127d6e6f8dc2901f4c7cd8 # 15:29 20+ 0 Merge
remote-tracking branch 'i2c/i2c/for-next'
git bisect good 462e0af1d10845875c68c4ebab8763e8aa745fc1 # 16:58 20+ 0 Merge
remote-tracking branch 'tip/auto-latest'
git bisect good 0a87e9437bf1d5d2947759165ed45d0e488e0958 # 17:08 20+ 0 Revert
"ipr: don't log error messages when applications issues illegal requests"
git bisect good 12308da406319a479375cf028966efca8aef6796 # 17:18 20+ 0 Merge
remote-tracking branch 'random/dev'
git bisect good 1f5c6373dd0714874a4870b6a94b8fc2510beb98 # 17:46 20+ 0 Merge
remote-tracking branch 'signal-cleanup/signal_v4'
git bisect bad e5d19a1e64b7124747bde87ff154ba1c7b1b9bd8 # 17:51 0- 2 Merge
branch 'akpm-current/current'
git bisect good a25c1d8786aeed7712fe04ce3f65b06f97d51072 # 18:01 20+ 0 sparc:
io: fix for asm-generic: io: implement relaxed accessor macros as conditional wrappers
git bisect bad 5be2e725b91d2b2e512ff66cfb23a239012dc955 # 18:10 0- 1 mm:
page_alloc: avoid wakeup kswapd on the unintended node
git bisect good caf144bbfe9ccab358ab7dd6c69a409f38002a89 # 18:25 20+ 0
proc/maps: make vm_is_stack() logic namespace-friendly
git bisect bad 85139d6797ed11cfefbe7b9b47f83f3a2f26848c # 18:39 0- 3
block_dev: implement readpages() to optimize sequential read
git bisect bad ef5783e1aa20c7d40ed952dfe9ace8f1f1a2e925 # 18:43 0- 1
mm/mmap.c: whitespace fixes
git bisect good 106033415f2306c188fc3993983856ff1b61730d # 19:04 20+ 0 mm/slab:
noinline __ac_put_obj()
git bisect good 7beefd02978e077edeee6bca011ed3357cb88ab4 # 19:25 20+ 0
kernel/kthread.c: partial revert of 81c98869faa5 ("kthread: ensure locality of
task_struct allocations")
git bisect good f49e433b66f5d6a0a0feef60c0d984daccdce2c4 # 19:44 20+ 0
mm/slab_common: fix build failure if CONFIG_SLUB
git bisect bad 997888488ef92da365b870247de773255227ce1f # 19:48 0- 1 mm/slab:
use percpu allocator for cpu cache
git bisect bad 8d8590d51e2b169f327a74c032333368f7f97f97 # 19:50 0- 1 mm/slab:
support slab merge
# first bad commit: [8d8590d51e2b169f327a74c032333368f7f97f97] mm/slab: support slab
merge
git bisect good f49e433b66f5d6a0a0feef60c0d984daccdce2c4 # 20:27 60+ 0
mm/slab_common: fix build failure if CONFIG_SLUB
git bisect bad 4d8426f9ac601db2a64fa7be64051d02b9c9fe01 # 20:27 0- 11 Add
linux-next specific files for 20140926
git bisect good 1e3827bf8aebe29af2d6e49b89d85dfae4d0154f # 20:48 60+ 0 Merge
branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
git bisect bad 4d8426f9ac601db2a64fa7be64051d02b9c9fe01 # 20:49 0- 11 Add
linux-next specific files for 20140926
This script may reproduce the error.
----------------------------------------------------------------------------
#!/bin/bash
kernel=$1
kvm=(
qemu-system-x86_64
-cpu kvm64
-enable-kvm
-kernel $kernel
-m 320
-smp 2
-net nic,vlan=1,model=e1000
-net user,vlan=1
-boot order=nc
-no-reboot
-watchdog i6300esb
-rtc base=localtime
-serial stdio
-display none
-monitor null
)
append=(
hung_task_panic=1
earlyprintk=ttyS0,115200
debug
apic=debug
sysrq_always_enabled
rcupdate.rcu_cpu_stall_timeout=100
panic=-1
softlockup_panic=1
nmi_watchdog=panic
oops=panic
load_ramdisk=2
prompt_ramdisk=0
console=ttyS0,115200
console=tty0
vga=normal
root=/dev/ram0
rw
drbd.minor_count=8
)
"${kvm[@]}" --append "${append[*]}"
----------------------------------------------------------------------------
Thanks,
Fengguang
_______________________________________________
LKP mailing list
LKP(a)linux.intel.com
10:35 p.m.
On Tue, Sep 30, 2014 at 03:56:24PM +0800, Fengguang Wu wrote:
Hi Joonsoo,
0day kernel testing robot got the below dmesg and the first bad commit is
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
commit 36fbfebe776eb5871d61e7a755c9feb1c96cc4aa
Author: Joonsoo Kim <iamjoonsoo.kim(a)lge.com>
AuthorDate: Tue Sep 23 11:52:35 2014 +1000
Commit: Stephen Rothwell <sfr(a)canb.auug.org.au>
CommitDate: Tue Sep 23 11:52:35 2014 +1000
mm/slab: support slab merge
Slab merge is good feature to reduce fragmentation. If new creating slab
have similar size and property with exsitent slab, this feature reuse it
rather than creating new one. As a result, objects are packed into fewer
slabs so that fragmentation is reduced.
Below is result of my testing.
* After boot, sleep 20; cat /proc/meminfo | grep Slab
<Before>
Slab: 25136 kB
<After>
Slab: 24364 kB
We can save 3% memory used by slab.
For supporting this feature in SLAB, we need to implement SLAB specific
kmem_cache_flag() and __kmem_cache_alias(), because SLUB implements some
SLUB specific processing related to debug flag and object size change on
these functions.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim(a)lge.com>
Cc: Christoph Lameter <cl(a)linux.com>
Cc: Pekka Enberg <penberg(a)kernel.org>
Cc: David Rientjes <rientjes(a)google.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
+----------------------------------------------+------------+------------+---------------+
| | 8c087489b8 | 36fbfebe77 | next-20140923
|
+----------------------------------------------+------------+------------+---------------+
| boot_successes | 60 | 0 | 1
|
| boot_failures | 0 | 20 | 314
|
| BUG:unable_to_handle_kernel | 0 | 20 | 312
|
| Oops | 0 | 20 | 312
|
| EIP_is_at_kernfs_link_sibling | 0 | 4 | 14
|
| Kernel_panic-not_syncing:Fatal_exception | 0 | 20 | 312
|
| backtrace:acpi_bus_scan | 0 | 4 | 14
|
| backtrace:acpi_scan_init | 0 | 20 | 45
|
| backtrace:acpi_init | 0 | 20 | 45
|
| backtrace:kernel_init_freeable | 0 | 20 | 312
|
| EIP_is_at_kernfs_add_one | 0 | 16 | 298
|
| backtrace:kobject_add_internal | 0 | 16 | 31
|
| backtrace:kobject_init_and_add | 0 | 16 | 31
|
| backtrace:acpi_scan_add_handler_with_hotplug | 0 | 16 | 31
|
| backtrace:acpi_pci_root_init | 0 | 16 | 31
|
| backtrace:tty_register_driver | 0 | 0 | 106
|
| backtrace:pty_init | 0 | 0 | 106
|
| backtrace:acpi_bus_register_driver | 0 | 0 | 1
|
| backtrace:acpi_button_driver_init | 0 | 0 | 1
|
| BUG:kernel_boot_crashed | 0 | 0 | 1
|
| BUG:kernel_test_crashed | 0 | 0 | 1
|
| backtrace:subsys_system_register | 0 | 0 | 160
|
| backtrace:container_dev_init | 0 | 0 | 160
|
| backtrace:driver_init | 0 | 0 | 160
|
+----------------------------------------------+------------+------------+---------------+
[ 0.463788] ACPI: (supports S0 S5)
[ 0.464003] ACPI: Using IOAPIC for interrupt routing
[ 0.464738] PCI: Using host bridge windows from ACPI; if necessary, use
"pci=nocrs" and report a bug
[ 0.466034] BUG: unable to handle kernel paging request at 00010023
[ 0.466989] IP: [<c117dcf9>] kernfs_add_one+0x89/0x130
[ 0.467812] *pdpt = 0000000000000000 *pde = f000ff53f000ff53
[ 0.468000] Oops: 0002 [#1] SMP
[ 0.468000] Modules linked in:
[ 0.468000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc6-00089-g36fbfeb #1
[ 0.468000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.468000] task: d303ec90 ti: d3040000 task.ti: d3040000
[ 0.468000] EIP: 0060:[<c117dcf9>] EFLAGS: 00010286 CPU: 0
[ 0.468000] EIP is at kernfs_add_one+0x89/0x130
[ 0.468000] EAX: 542572cb EBX: 00010003 ECX: 00000008 EDX: 2c8de598
[ 0.468000] ESI: d311de10 EDI: d311de70 EBP: d3041dd8 ESP: d3041db4
[ 0.468000] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[ 0.468000] CR0: 8005003b CR2: 00010023 CR3: 01a8a000 CR4: 000006f0
[ 0.468000] Stack:
[ 0.468000] d3006f00 00000202 d311de70 d311de10 d3041dd8 c117dba0 d311de10 c159a5c0
[ 0.468000] c1862a00 d3041df0 c117f0f2 00000000 c18629f4 d311de70 00000000 d3041e2c
[ 0.468000] c117f8b5 00001000 00000000 c159a5c0 c18629f4 00000000 00000001 c1862a00
[ 0.468000] Call Trace:
[ 0.468000] [<c117dba0>] ? kernfs_new_node+0x30/0x40
[ 0.468000] [<c117f0f2>] __kernfs_create_file+0x92/0xc0
[ 0.468000] [<c117f8b5>] sysfs_add_file_mode_ns+0x95/0x190
[ 0.468000] [<c117f9d7>] sysfs_create_file_ns+0x27/0x40
[ 0.468000] [<c1252ef6>] kobject_add_internal+0x136/0x2c0
[ 0.468000] [<c125e360>] ? kvasprintf+0x40/0x50
[ 0.468000] [<c1252a92>] ? kobject_set_name_vargs+0x42/0x60
[ 0.468000] [<c12530b5>] kobject_init_and_add+0x35/0x50
[ 0.468000] [<c12ad04f>] acpi_sysfs_add_hotplug_profile+0x24/0x4a
[ 0.468000] [<c12a7280>] acpi_scan_add_handler_with_hotplug+0x21/0x28
[ 0.468000] [<c18df524>] acpi_pci_root_init+0x20/0x22
[ 0.468000] [<c18df0e1>] acpi_scan_init+0x24/0x16d
[ 0.468000] [<c18def73>] acpi_init+0x20c/0x224
[ 0.468000] [<c18ded67>] ? acpi_sleep_init+0xab/0xab
[ 0.468000] [<c100041e>] do_one_initcall+0x7e/0x1b0
[ 0.468000] [<c18ded67>] ? acpi_sleep_init+0xab/0xab
[ 0.468000] [<c18b24ba>] ? repair_env_string+0x12/0x54
[ 0.468000] [<c18b24a8>] ? initcall_blacklist+0x7c/0x7c
[ 0.468000] [<c105e100>] ? parse_args+0x160/0x3f0
[ 0.468000] [<c18b2bd1>] kernel_init_freeable+0xfc/0x179
[ 0.468000] [<c156782b>] kernel_init+0xb/0xd0
[ 0.468000] [<c1574601>] ret_from_kernel_thread+0x21/0x30
[ 0.468000] [<c1567820>] ? rest_init+0xb0/0xb0
[ 0.468000] Code: 26 00 83 e1 10 75 5b 8b 46 24 e8 b3 ea ff ff 89 46 38 89 f0 e8 d9 f9
ff ff 85 c0 89 c3 75 ca 8b 5f 5c 85 db 74 11 e8 97 90 f1 ff <89> 43 20 89 53 24 89
43 28 89 53 2c b8 c0 2f 85 c1 e8 d1 36 3f
[ 0.468000] EIP: [<c117dcf9>] kernfs_add_one+0x89/0x130 SS:ESP 0068:d3041db4
[ 0.468000] CR2: 0000000000010023
[ 0.468000] ---[ end trace 4fa173691404b63f ]---
[ 0.468000] Kernel panic - not syncing: Fatal exception
git bisect start 55f21306900abf9f9d2a087a127ff49c6d388ad2
0f33be009b89d2268e94194dc4fd01a7851b6d51 --
git bisect good 18c13e2d9b75e2760e6520f2fde00401192956f3 # 17:56 20+ 0 Merge
remote-tracking branch 'bluetooth/master'
git bisect good abf79495f38ba66f750566b3f0a8da8dd94b4dc3 # 18:03 20+ 0 Merge
remote-tracking branch 'ftrace/for-next'
git bisect good 0bed22034e26a3c37ee4407fccffa8c095d5e144 # 18:09 20+ 0 Merge
remote-tracking branch 'pinctrl/for-next'
git bisect good 15c9281a15ed7718868d115d4d00619b0b7a2624 # 18:14 20+ 0 Merge
remote-tracking branch 'clk/clk-next'
git bisect good 50939531dea1b913b7fa29f9bbc69feafefd090c # 18:23 20+ 0 Merge
branch 'rd-docs/master'
git bisect good aa881e3c5e87c8aa23519f40554897d56f32b935 # 18:49 20+ 0 Merge
remote-tracking branch 'powerpc-mpe/next'
git bisect bad 81b63d14db32bd7706c955d1e04e65b152b2277a # 18:57 0- 2 Merge
branch 'akpm-current/current'
git bisect bad f313ca82d72066a3c44fd6c66cee57b25de43aa9 # 19:31 0- 1
introduce-dump_vma-fix
git bisect good 2c5fe9213048c5640b8e46407f5614038c03ad93 # 20:16 20+ 0 mm: fix
kmemcheck.c build errors
git bisect bad 69454f8be7f621ac8c3c6c9763bb70e116988942 # 20:35 0- 18
block_dev: implement readpages() to optimize sequential read
git bisect bad 66a31d528a1e3d483be2b1c993ec1268412f0074 # 20:40 0- 1
memory-hotplug-add-sysfs-zones_online_to-attribute-fix-2
git bisect good 5e8acb68610c077b08cb3f16305aa3cc22e5d2a8 # 21:07 20+ 0
kernel/kthread.c: partial revert of 81c98869faa5 ("kthread: ensure locality of
task_struct allocations")
git bisect bad 36fbfebe776eb5871d61e7a755c9feb1c96cc4aa # 22:06 0- 10
mm/slab: support slab merge
git bisect good 11e57381eced875ef5a6fea4005fdf72b6f68eff # 22:19 20+ 0
mm/slab_common: commonize slab merge logic
git bisect good 8c087489b8a32b9235f7f9417390c62d93aba522 # 22:24 20+ 0
mm/slab_common: fix build failure if CONFIG_SLUB
# first bad commit: [36fbfebe776eb5871d61e7a755c9feb1c96cc4aa] mm/slab: support slab
merge
git bisect good 8c087489b8a32b9235f7f9417390c62d93aba522 # 22:26 60+ 0
mm/slab_common: fix build failure if CONFIG_SLUB
git bisect bad 55f21306900abf9f9d2a087a127ff49c6d388ad2 # 22:26 0- 314 Add
linux-next specific files for 20140923
git bisect good f4cb707e7ad9727a046b463232f2de166e327d3e # 22:32 60+ 0 Merge
tag 'pm+acpi-3.17-rc7' of
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
git bisect bad 4d8426f9ac601db2a64fa7be64051d02b9c9fe01 # 22:36 0- 60 Add
linux-next specific files for 20140926
This script may reproduce the error.
----------------------------------------------------------------------------
#!/bin/bash
kernel=$1
kvm=(
qemu-system-x86_64
-cpu kvm64
-enable-kvm
-kernel $kernel
-m 320
-smp 1
-net nic,vlan=1,model=e1000
-net user,vlan=1
-boot order=nc
-no-reboot
-watchdog i6300esb
-rtc base=localtime
-serial stdio
-display none
-monitor null
)
append=(
hung_task_panic=1
earlyprintk=ttyS0,115200
debug
apic=debug
sysrq_always_enabled
rcupdate.rcu_cpu_stall_timeout=100
panic=-1
softlockup_panic=1
nmi_watchdog=panic
oops=panic
load_ramdisk=2
prompt_ramdisk=0
console=ttyS0,115200
console=tty0
vga=normal
root=/dev/ram0
rw
drbd.minor_count=8
)
"${kvm[@]}" --append "${append[*]}"
----------------------------------------------------------------------------
Thanks Fengguang.
I can reproduce this bug in my system with your configuration.
Below is fix for this bug.
Hello Andrew,
Could you take this patch?
Thanks.
----------->8------------------
From e9c884c1f807dc9de2f4cc3b2779a014e5ebb7a1 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim(a)lge.com>
Date: Thu, 2 Oct 2014 12:09:41 +0900
Subject: [PATCH] mm/slab: adjust object_size in order to fix bug in slab
merge
Fengguang reported following bug and his bisect result points
to this patch ('mm/slab: support slab merge') as root cause.
[ 0.466034] BUG: unable to handle kernel paging request at 00010023
[ 0.466989] IP: [<c117dcf9>] kernfs_add_one+0x89/0x130
[ 0.467812] *pdpt = 0000000000000000 *pde = f000ff53f000ff53
[ 0.468000] Oops: 0002 [#1] SMP
[ 0.468000] Modules linked in:
[ 0.468000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc6-00089-g36fbfeb #1
[ 0.468000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.468000] task: d303ec90 ti: d3040000 task.ti: d3040000
[ 0.468000] EIP: 0060:[<c117dcf9>] EFLAGS: 00010286 CPU: 0
[ 0.468000] EIP is at kernfs_add_one+0x89/0x130
[ 0.468000] EAX: 542572cb EBX: 00010003 ECX: 00000008 EDX: 2c8de598
[ 0.468000] ESI: d311de10 EDI: d311de70 EBP: d3041dd8 ESP: d3041db4
[ 0.468000] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[ 0.468000] CR0: 8005003b CR2: 00010023 CR3: 01a8a000 CR4: 000006f0
[ 0.468000] Stack:
[ 0.468000] d3006f00 00000202 d311de70 d311de10 d3041dd8 c117dba0 d311de10 c159a5c0
[ 0.468000] c1862a00 d3041df0 c117f0f2 00000000 c18629f4 d311de70 00000000 d3041e2c
[ 0.468000] c117f8b5 00001000 00000000 c159a5c0 c18629f4 00000000 00000001 c1862a00
[ 0.468000] Call Trace:
[ 0.468000] [<c117dba0>] ? kernfs_new_node+0x30/0x40
[ 0.468000] [<c117f0f2>] __kernfs_create_file+0x92/0xc0
[ 0.468000] [<c117f8b5>] sysfs_add_file_mode_ns+0x95/0x190
[ 0.468000] [<c117f9d7>] sysfs_create_file_ns+0x27/0x40
[ 0.468000] [<c1252ef6>] kobject_add_internal+0x136/0x2c0
[ 0.468000] [<c125e360>] ? kvasprintf+0x40/0x50
[ 0.468000] [<c1252a92>] ? kobject_set_name_vargs+0x42/0x60
[ 0.468000] [<c12530b5>] kobject_init_and_add+0x35/0x50
[ 0.468000] [<c12ad04f>] acpi_sysfs_add_hotplug_profile+0x24/0x4a
[ 0.468000] [<c12a7280>] acpi_scan_add_handler_with_hotplug+0x21/0x28
[ 0.468000] [<c18df524>] acpi_pci_root_init+0x20/0x22
[ 0.468000] [<c18df0e1>] acpi_scan_init+0x24/0x16d
[ 0.468000] [<c18def73>] acpi_init+0x20c/0x224
[ 0.468000] [<c18ded67>] ? acpi_sleep_init+0xab/0xab
[ 0.468000] [<c100041e>] do_one_initcall+0x7e/0x1b0
[ 0.468000] [<c18ded67>] ? acpi_sleep_init+0xab/0xab
[ 0.468000] [<c18b24ba>] ? repair_env_string+0x12/0x54
[ 0.468000] [<c18b24a8>] ? initcall_blacklist+0x7c/0x7c
[ 0.468000] [<c105e100>] ? parse_args+0x160/0x3f0
[ 0.468000] [<c18b2bd1>] kernel_init_freeable+0xfc/0x179
[ 0.468000] [<c156782b>] kernel_init+0xb/0xd0
[ 0.468000] [<c1574601>] ret_from_kernel_thread+0x21/0x30
[ 0.468000] [<c1567820>] ? rest_init+0xb0/0xb0
[snip...]
[ 0.468000] EIP: [<c117dcf9>] kernfs_add_one+0x89/0x130 SS:ESP 0068:d3041db4
[ 0.468000] CR2: 0000000000010023
[ 0.468000] ---[ end trace 4fa173691404b63f ]---
[ 0.468000] Kernel panic - not syncing: Fatal exception
This error is caused by wrongly initialized object due to slab merge.
Size of vm_area_struct is 92 bytes in this configuration, and, for better
alignment, this kmem_cache manage memory in 96 bytes unit. But, maybe for
performance reason, if user requests zeroing for this object, object is
cleared up to 92 bytes.
Meanwhile, size of kernfs_node_cache is 96 bytes so that it can be merged
with kmem_cache for vm_area_struct. In this situation, if user request
zeroing for objects for kernfs_node_cache, object is only cleared up to
92 bytes. So, kernfs_node had odd value on iattr field and this results in
de-referencing wrong address bug.
To fix this problem, object size is adjusted when merging occurs.
After this change, zeroing will be done to complete object so that
de-referencing wrong address can't happen.
Reported-by: Fengguang Wu <fengguang.wu(a)intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim(a)lge.com>
---
mm/slab.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/mm/slab.c b/mm/slab.c
index c55b1ec..6307131 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2118,9 +2118,15 @@ __kmem_cache_alias(const char *name, size_t size, size_t align,
struct kmem_cache *cachep;
cachep = find_mergeable(size, align, flags, name, ctor);
- if (cachep)
+ if (cachep) {
cachep->refcount++;
+ /*
+ * Adjust the object sizes so that we clear
+ * the complete object on kzalloc.
+ */
+ cachep->object_size = max_t(int, cachep->object_size, size);
+ }
return cachep;
}
--
1.7.9.5
2391
days inactive
2393
days old
2 comments
2 participants
participants (2)
-
Fengguang Wu -
Joonsoo Kim