Hi Neil, I checked mobprobe and it looks like its last step was to flush cpu workqueue while trying to stop_machine, which I don't quite understand why. Hereunder 83356 is checksctp process, and 83360 is mobprobe process root 83356 83270 0 2244 452 0 Mar20 pts/0 00:00:00 checksctp root 83359 16 0 0 0 1 Mar20 ? 00:00:00 [khelper] root 83360 83359 0 2307 712 0 Mar20 ? 00:00:00 /sbin/modprobe -q -- net_pf_2_proto_132 cat /proc/83360/stack [<ffffffff8105fb1c>] flush_cpu_workqueue+0x4c/0x80 [<ffffffff8105fd5c>] flush_workqueue+0x3c/0x60 [<ffffffff810933e9>] __stop_machine+0xf9/0x120 [<ffffffff8109365f>] stop_machine+0x3f/0x70 [<ffffffff8107fddc>] unwind_remove_table+0x3c/0x70 [<ffffffff8107d047>] sys_init_module+0x157/0x270 [<ffffffff81002f7b>] system_call_fastpath+0x16/0x1b [<00007fc7c1bccf4a>] 0x7fc7c1bccf4a [<ffffffffffffffff>] 0xffffffffffffffff Regards, Jerry On Fri, Mar 20, 2015 at 11:11 AM, Neil Horman <nhorman@xxxxxxxxxxxxx> wrote: > On Fri, Mar 20, 2015 at 10:44:56AM -0700, Jerry Jerry wrote: >> Thanks, Neil, not sure if this is cause but I'll double check. >> >> Meanwhile, we hit another issue that checksctp hangs: >> >> >> 83356 pts/0 D+ 0:00 checksctp >> >> And /proc/83356/stack shows: >> >> [<ffffffff8105f357>] call_usermodehelper_exec+0xc7/0xd0 >> [<ffffffff8105f5a2>] __request_module+0x142/0x190 >> [<ffffffff8134d3bb>] inet_create+0x10b/0x300 >> [<ffffffff812e1aad>] __sock_create+0x12d/0x2c0 >> [<ffffffff812e1f1d>] sys_socket+0x3d/0x70 >> [<ffffffff81002f7b>] system_call_fastpath+0x16/0x1b >> [<00007f29c4c2fa07>] 0x7f29c4c2fa07 >> [<ffffffffffffffff>] 0xffffffffffffffff >> > This indicates that the kernel is attempting to demand load the sctp module. If > its hung in purpituity, that means that the callout process (forked by > call_usermodehelper_exec) is blocked. Look for the running modprobe process, > and see whats blocking that. That will lead you a step closer to your root > cause. > >> We have libsctp.so.1.0.16 under /usr/local/lib/ but rpm -V >> lksctp-tools shows it's not installed. Could this matter, or there >> might be other reasons? >> > No RHEL shipped rpm installs things to /usr/local/lib, ever. Sounds like > perhaps you've built your own libsctp and installed it. As to which one is in > use (the one in /usr/local/lib or the one in /usr/lib, where lksctp-tools rpm > install libraries), is a matter of how your LD_LIBRARY_PATH is set. > > Neil > >> Regards, >> Jerry >> >> On Fri, Mar 20, 2015 at 4:49 AM, Neil Horman <nhorman@xxxxxxxxxxxxx> wrote: >> > On Thu, Mar 19, 2015 at 07:15:28PM -0700, Jerry Jerry wrote: >> >> Hello everyone, >> >> >> >> We had another problem today, where modprobe shows an error in >> >> /var/log/message when we ran an sctp application: >> >> >> >> modprobe: FATAL: Error inserting sctp >> >> (/lib/modules/2.6.32.12-0.7-default/kernel/net/sctp/sctp.ko): Invalid >> >> argument >> >> >> >> I'm wondering what might be possible causes of this and how should we >> >> bypass this.... Appreciate any comments and suggestions. >> >> >> >> Regards, >> >> Jerry >> > EINVAL is returned by mod_sysfs_setup. Ostensibly its because you either >> > specified a module option that doesn't exist, or because the module is already >> > loaded. There could be other reasons, but those are the ones that pop >> > immediately to mind. >> > >> > Neil >> > >> >> -- >> >> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in >> >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> >> -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html