On 11/01/2012 01:30 PM, Hal Rosenstock wrote: > On 11/1/2012 11:12 AM, Or Gerlitz wrote: >> On 19/10/2012 23:58, Kleber Sacilotto de Souza wrote: >>> During PCI error recovery, the calls to wait_for_completion() in the >>> infiniband core path can hang waiting for some tasks that will never >>> complete, since the hardware is nonfunctional. >>> >>> INFO: task eehd:16029 blocked for more than 120 seconds. >>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this >>> message. >>> eehd D 0000000000000000 9664 16029 3093 0x00000080 >>> Call Trace: >>> [c0000000af8430e0] [c0000000be05e200] 0xc0000000be05e200 (unreliable) >>> [c0000000af8432b0] [c000000000014070] .__switch_to+0x130/0x250 >>> [c0000000af843360] [c000000000777c5c] .__schedule+0x40c/0x920 >>> [c0000000af843600] [c000000000775a10] .schedule_timeout+0x210/0x260 >>> [c0000000af8436e0] [c000000000777658] .wait_for_common+0xf8/0x210 >>> [c0000000af8437c0] [d000000004113538] >>> .ib_unregister_mad_agent+0x498/0x690 [ib_mad] >>> [c0000000af8438c0] [d0000000042c01f4] .ib_sa_remove_one+0xe4/0x180 >>> [ib_sa] >>> [c0000000af843970] [d0000000040952e8] .ib_unregister_device+0x78/0x170 >>> [ib_core] >>> [c0000000af843a10] [d000000004183290] .mlx4_ib_remove+0x40/0x1f0 >>> [mlx4_ib] >>> [c0000000af843ab0] [d000000003f6ab54] .mlx4_remove_device+0xd4/0x110 >>> [mlx4_core] >>> [c0000000af843b40] [d000000003f6abfc] >>> .mlx4_unregister_device+0x6c/0xf0 [mlx4_core] >>> [c0000000af843be0] [d000000003f6f19c] .mlx4_remove_one+0x10c/0x3a0 >>> [mlx4_core] >>> [c0000000af843c80] [d000000003f6f448] .mlx4_pci_err_detected+0x18/0x40 >>> [mlx4_core] >>> [c0000000af843d00] [c000000000058a50] .eeh_report_error+0x70/0xe0 >>> [c0000000af843d90] [c0000000003e4d94] .pci_walk_bus+0xa4/0x140 >>> [c0000000af843e50] [c000000000058628] .handle_eeh_events+0x1f8/0x480 >>> [c0000000af843f00] [c000000000058dfc] .eeh_event_handler+0x13c/0x1e0 >>> [c0000000af843f90] [c00000000002031c] .kernel_thread+0x54/0x70 >>> >>> This patch fixes the issue by replacing the calls to >>> wait_for_completion() by wait_for_completion_timeout(), providing a >>> timeout of 5 seconds to wait for the normal completion of the task. >>> >>> Signed-off-by: Kleber Sacilotto de Souza<kleb...@linux.vnet.ibm.com> >>> --- >>> drivers/infiniband/core/addr.c | 2 +- >>> drivers/infiniband/core/cm.c | 2 +- >>> drivers/infiniband/core/cma.c | 4 ++-- >>> drivers/infiniband/core/iwcm.c | 2 +- >>> drivers/infiniband/core/mad.c | 4 ++-- >>> drivers/infiniband/core/mad_rmpp.c | 2 +- >>> drivers/infiniband/core/multicast.c | 4 ++-- >>> drivers/infiniband/core/sa_query.c | 2 +- >> for all the above files, your patch makes sense, since the >> completion/refcount logic >> relate to waiting for event that needs to come from the device. > Is this a fix or a workaround for some other underlying issue which > needs fixing ? > > What happens when modules are reloaded after this ? Do things still work > ? Are resources lost ?
After the error is recovered, the IB devices resume their normal operations, and the modules can be reloaded successfully. > > -- Hal > >>> drivers/infiniband/core/ucm.c | 2 +- >>> drivers/infiniband/core/ucma.c | 2 +- >> On these files, as far as I understand this code from quick looking, I'm >> not sure on what >> exactly the completion objects protects, Sean? >> >> Or. >> >>> drivers/infiniband/core/uverbs_main.c | 4 ++-- >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in >> the body of a message to majord...@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> -- Kleber Sacilotto de Souza IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
