* Srikar Dronamraju <[email protected]> [2012-10-13 23:36:18]:
> > +
> > +bool numa_hinting_fault(struct page *page, int numpages)
> > +{
> > + bool migrated = false;
> > +
> > + /*
> > + * "current->mm" could be different from the "mm" where the
> > + * NUMA hinting page fault happened, if get_user_pages()
> > + * triggered the fault on some other process "mm". That is ok,
> > + * all we care about is to count the "page_nid" access on the
> > + * current->task_autonuma, even if the page belongs to a
> > + * different "mm".
> > + */
> > + WARN_ON_ONCE(!current->mm);
>
> Given the above comment, Do we really need this warn_on?
> I think I have seen this warning when using autonuma.
>
------------[ cut here ]------------
WARNING: at ../mm/autonuma.c:359 numa_hinting_fault+0x60d/0x7c0()
Hardware name: BladeCenter HS22V -[7871AC1]-
Modules linked in: ebtable_nat ebtables autofs4 sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf bridge stp llc iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vhost_net macvtap macvlan tun iTCO_wdt iTCO_vendor_support cdc_ether usbnet mii kvm_intel kvm microcode serio_raw lpc_ich mfd_core i2c_i801 i2c_core shpchp ioatdma i7core_edac edac_core bnx2 ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase scsi_transport_sas dm_mirror dm_region_hash dm_log dm_mod
Pid: 116, comm: ksmd Tainted: G D 3.6.0-autonuma27+ #3
Call Trace:
[<ffffffff8105194f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff810519aa>] warn_slowpath_null+0x1a/0x20
[<ffffffff81153f0d>] numa_hinting_fault+0x60d/0x7c0
[<ffffffff8104ae90>] ? flush_tlb_mm_range+0x250/0x250
[<ffffffff8103b82e>] ? physflat_send_IPI_mask+0xe/0x10
[<ffffffff81036db5>] ? native_send_call_func_ipi+0xa5/0xd0
[<ffffffff81154255>] pmd_numa_fixup+0x195/0x350
[<ffffffff81135ef4>] handle_mm_fault+0x2c4/0x3d0
[<ffffffff8113139c>] ? follow_page+0x2fc/0x4f0
[<ffffffff81156364>] break_ksm+0x74/0xa0
[<ffffffff81156562>] break_cow+0xa2/0xb0
[<ffffffff81158444>] ksm_scan_thread+0xb54/0xd50
[<ffffffff81075cf0>] ? wake_up_bit+0x40/0x40
[<ffffffff811578f0>] ? run_store+0x340/0x340
[<ffffffff8107563e>] kthread+0x9e/0xb0
[<ffffffff814e8c44>] kernel_thread_helper+0x4/0x10
[<ffffffff810755a0>] ? kthread_freezable_should_stop+0x70/0x70
[<ffffffff814e8c40>] ? gs_change+0x13/0x13
---[ end trace 8f50820d1887cf93 ]-
While running specjbb on a 2 node box. Seems pretty easy to produce this.
--
Thanks and Regards
Srikar
On Mon, Oct 15, 2012 at 01:54:13PM +0530, Srikar Dronamraju wrote:
> * Srikar Dronamraju <[email protected]> [2012-10-13 23:36:18]:
>
> > > +
> > > +bool numa_hinting_fault(struct page *page, int numpages)
> > > +{
> > > + bool migrated = false;
> > > +
> > > + /*
> > > + * "current->mm" could be different from the "mm" where the
> > > + * NUMA hinting page fault happened, if get_user_pages()
> > > + * triggered the fault on some other process "mm". That is ok,
> > > + * all we care about is to count the "page_nid" access on the
> > > + * current->task_autonuma, even if the page belongs to a
> > > + * different "mm".
> > > + */
> > > + WARN_ON_ONCE(!current->mm);
> >
> > Given the above comment, Do we really need this warn_on?
> > I think I have seen this warning when using autonuma.
> >
>
> ------------[ cut here ]------------
> WARNING: at ../mm/autonuma.c:359 numa_hinting_fault+0x60d/0x7c0()
> Hardware name: BladeCenter HS22V -[7871AC1]-
> Modules linked in: ebtable_nat ebtables autofs4 sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf bridge stp llc iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vhost_net macvtap macvlan tun iTCO_wdt iTCO_vendor_support cdc_ether usbnet mii kvm_intel kvm microcode serio_raw lpc_ich mfd_core i2c_i801 i2c_core shpchp ioatdma i7core_edac edac_core bnx2 ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase scsi_transport_sas dm_mirror dm_region_hash dm_log dm_mod
> Pid: 116, comm: ksmd Tainted: G D 3.6.0-autonuma27+ #3
The kernel is tainted "D" which implies that it has already oopsed
before this warning was triggered. What was the other oops?
--
Mel Gorman
SUSE Labs
* Mel Gorman <[email protected]> [2012-10-15 10:20:44]:
> On Mon, Oct 15, 2012 at 01:54:13PM +0530, Srikar Dronamraju wrote:
> > * Srikar Dronamraju <[email protected]> [2012-10-13 23:36:18]:
> >
> > > > +
> > > > +bool numa_hinting_fault(struct page *page, int numpages)
> > > > +{
> > > > + bool migrated = false;
> > > > +
> > > > + /*
> > > > + * "current->mm" could be different from the "mm" where the
> > > > + * NUMA hinting page fault happened, if get_user_pages()
> > > > + * triggered the fault on some other process "mm". That is ok,
> > > > + * all we care about is to count the "page_nid" access on the
> > > > + * current->task_autonuma, even if the page belongs to a
> > > > + * different "mm".
> > > > + */
> > > > + WARN_ON_ONCE(!current->mm);
> > >
> > > Given the above comment, Do we really need this warn_on?
> > > I think I have seen this warning when using autonuma.
> > >
> >
> > ------------[ cut here ]------------
> > WARNING: at ../mm/autonuma.c:359 numa_hinting_fault+0x60d/0x7c0()
> > Hardware name: BladeCenter HS22V -[7871AC1]-
> > Modules linked in: ebtable_nat ebtables autofs4 sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf bridge stp llc iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vhost_net macvtap macvlan tun iTCO_wdt iTCO_vendor_support cdc_ether usbnet mii kvm_intel kvm microcode serio_raw lpc_ich mfd_core i2c_i801 i2c_core shpchp ioatdma i7core_edac edac_core bnx2 ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase scsi_transport_sas dm_mirror dm_region_hash dm_log dm_mod
> > Pid: 116, comm: ksmd Tainted: G D 3.6.0-autonuma27+ #3
>
> The kernel is tainted "D" which implies that it has already oopsed
> before this warning was triggered. What was the other oops?
>
Yes, But this oops shows up even with v3.6 kernel and not related to autonuma changes.
BUG: unable to handle kernel NULL pointer dereference at 00000000000000dc
IP: [<ffffffffa0015543>] i7core_inject_show_col+0x13/0x50 [i7core_edac]
PGD 671ce4067 PUD 671257067 PMD 0
Oops: 0000 [#3] SMP
Modules linked in: ebtable_nat ebtables autofs4 sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf bridge stp llc iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vhost_net macvtap macvlan tun iTCO_wdt iTCO_vendor_support cdc_ether usbnet mii kvm_intel kvm microcode serio_raw i2c_i801 i2c_core lpc_ich mfd_core shpchp ioatdma i7core_edac edac_core bnx2 sg ixgbe dca mdio ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase scsi_transport_sas dm_mirror dm_region_hash dm_log dm_mod
CPU 1
Pid: 10833, comm: tar Tainted: G D 3.6.0-autonuma27+ #2 IBM BladeCenter HS22V -[7871AC1]-/81Y5995
RIP: 0010:[<ffffffffa0015543>] [<ffffffffa0015543>] i7core_inject_show_col+0x13/0x50 [i7core_edac]
RSP: 0018:ffff88033a10fe68 EFLAGS: 00010286
RAX: ffff880371bd5000 RBX: ffffffffa0018880 RCX: ffffffffa0015530
RDX: 0000000000000000 RSI: ffffffffa0018880 RDI: ffff88036f0af000
RBP: ffff88033a10fe68 R08: ffff88036f0af010 R09: ffffffff8152a140
R10: 0000000000002de7 R11: 0000000000000246 R12: ffff88033a10ff48
R13: 0000000000001000 R14: 0000000000ccc600 R15: ffff88036f233e40
FS: 00007f57c07c47a0(0000) GS:ffff88037fc20000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000dc CR3: 0000000671e12000 CR4: 00000000000027e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process tar (pid: 10833, threadinfo ffff88033a10e000, task ffff88036e45e7f0)
Stack:
ffff88033a10fe98 ffffffff8132b1e7 ffff88033a10fe88 ffffffff81110b5e
ffff88033a10fe98 ffff88036f233e60 ffff88033a10fef8 ffffffff811d2d1e
0000000000001000 ffff88036f0af010 ffffffff8152a140 ffff88036d875e48
Call Trace:
[<ffffffff8132b1e7>] dev_attr_show+0x27/0x50
[<ffffffff81110b5e>] ? __get_free_pages+0xe/0x50
[<ffffffff811d2d1e>] sysfs_read_file+0xce/0x1c0
[<ffffffff81162ed5>] vfs_read+0xc5/0x190
[<ffffffff811630a1>] sys_read+0x51/0x90
[<ffffffff814e29e9>] system_call_fastpath+0x16/0x1b
Code: 89 c7 48 c7 c6 64 79 01 a0 31 c0 e8 18 8d 23 e1 c9 48 98 c3 0f 1f 40 00 55 48 89 e5 66 66 66 66 90 48 89 d0 48 8b 97 c0 03 00 00 <8b> 92 dc 00 00 00 85 d2 78 1b 48 89 c7 48 c7 c6 69 79 01 a0 31
RIP [<ffffffffa0015543>] i7core_inject_show_col+0x13/0x50 [i7core_edac]
RSP <ffff88033a10fe68>
CR2: 00000000000000dc
---[ end trace f0a3a4c8c85ff69f ]---
--
Thanks and Regards
Srikar