* Mel Gorman <mel@xxxxxxxxx> [2012-10-15 10:20:44]: > On Mon, Oct 15, 2012 at 01:54:13PM +0530, Srikar Dronamraju wrote: > > * Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> [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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>