On 04/25/2013 07:48 AM, Yinghai Lu wrote: > On Wed, Apr 24, 2013 at 10:11 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: >> On Wed, Apr 24, 2013 at 2:36 AM, Gu Zheng <guz.fnst@xxxxxxxxxxxxxx> wrote: >>> On 04/19/2013 03:43 AM, Yinghai Lu wrote: >> [...] >>>> I can not find where that reference count get reduced! >>>> in the my test patches that I sent, it does have have that in remove path. >>>> >>>> What is reason for you to remove that line? >>>> >>>> After put the line back, your test still can pass? >>> >>> Hi Yinghai, >>> The remove test script still can pass if we reduce the reference of pci_bus when destroying >>> the pci_dev, so does your patch, but a list_del corruption warning occurs in the bottom half routine: >> >> That is not clear. >> >> your patchset does not have list_del corruption warning? >> >>> ------------[ cut here ]------------ >>> WARNING: at lib/list_debug.c:53 __list_del_entry+0x63/0xd0() >>> Hardware name: PRIMEQUEST 1800E >>> list_del corruption, ffff8807d1b6c000->next is LIST_POISON1 (dead000000100100) >>> Modules linked in: shpchp ebtable_nat ebtables xt_CHECKSUM iptable_mangle bridge stp llc autofs4 sunrpc cpufreq_ondemand ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vfat fat dm_mirror dm_region_hash dm_log dm_mod vhost_net macvtap macvlan tun uinput iTCO_wdt iTCO_vendor_support acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel microcode pcspkr sg i2c_i801 lpc_ich mfd_core i7core_edac edac_core ioatdma e1000e igb dca i2c_algo_bit i2c_core ptp pps_core ext4(F) mbcache(F) jbd2(F) sd_mod(F) crc_t10dif(F) megaraid_sas(F) mptsas(F) mptscsih(F) mptbase(F) scsi_transport_sas(F) >>> Pid: 6, comm: kworker/u:0 Tainted: GF W 3.9.0-rc7-pci-remove-test+ #59 >>> Call Trace: >>> [<ffffffff81056d4f>] warn_slowpath_common+0x7f/0xc0 >>> [<ffffffff81056e46>] warn_slowpath_fmt+0x46/0x50 >>> [<ffffffff81280b13>] __list_del_entry+0x63/0xd0 >>> [<ffffffff81280b91>] list_del+0x11/0x40 >>> [<ffffffff81298331>] pci_destroy_dev+0x31/0xc0 >>> [<ffffffff812985bb>] pci_remove_bus_device+0x5b/0x70 >>> [<ffffffff812985ee>] pci_stop_and_remove_bus_device+0x1e/0x30 >>> [<ffffffff8129fc89>] remove_callback+0x29/0x40 >>> [<ffffffff811f3b84>] sysfs_schedule_callback_work+0x24/0x70 >>> [<ffffffff81073d85>] process_one_work+0x185/0x3f0 >>> [<ffffffff810763e9>] worker_thread+0x119/0x380 >>> [<ffffffff810762d0>] ? manage_workers+0x180/0x180 >>> [<ffffffff8107b6ae>] kthread+0xce/0xe0 >>> [<ffffffff8107b5e0>] ? kthread_freezable_should_stop+0x70/0x70 >>> [<ffffffff815724ac>] ret_from_fork+0x7c/0xb0 >>> [<ffffffff8107b5e0>] ? kthread_freezable_should_stop+0x70/0x70 >>> ---[ end trace 9c05e382f933a515 ]--- > > Attached patch on top of current linus tree should fix the racing problem. > > We don't need to bother to add get bus ref. etc. > > Let us know your test result. Hi Yinghai, I tested your new patch on latest linus tree(824282ca7d250), it works well, no list_del corruption warning. And the dmesg info seems that every thing goes well. [root@DP guzheng]# echo -n 1 > /sys/bus/pci/devices/0000\:10\:00.0/remove ; echo -n 1 > /sys/bus/pci/devices/0000\:1a\:01.0/remove [root@DP guzheng]# dmesg pciehp 0000:1a:01.0:pcie24: unloading service driver pciehp pciehp 0000:1a:03.0:pcie24: unloading service driver pciehp pciehp 0000:1a:02.0:pcie24: unloading service driver pciehp pciehp 0000:1a:00.0:pcie24: unloading service driver pciehp igb 0000:15:00.1: removed PHC on eth7 igb 0000:15:00.0: removed PHC on eth6 igb 0000:14:00.1: removed PHC on eth5 igb 0000:14:00.0: removed PHC on eth4 pci_bus 0000:14: busn_res: [bus 14] is released pci_bus 0000:15: busn_res: [bus 15] is released pci_bus 0000:16: busn_res: [bus 16] is released pci_bus 0000:17: busn_res: [bus 17] is released pci_bus 0000:18: busn_res: [bus 18] is released pci_bus 0000:13: busn_res: [bus 13-18] is released pci_bus 0000:12: busn_res: [bus 12-18] is released pci_bus 0000:1b: busn_res: [bus 1b] is released pci_bus 0000:1d: busn_res: [bus 1d] is released pci_bus 0000:1e: busn_res: [bus 1e] is released pci_bus 0000:1c: busn_res: [bus 1c] is released pci_bus 0000:1a: busn_res: [bus 1a-1e] is released pci_bus 0000:19: busn_res: [bus 19-1e] is released pci_bus 0000:11: busn_res: [bus 11-1e] is released Best regards, Gu > > Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
