Thanks! We're having the developers look into this issue. Todd Fujinaka Software Application Engineer Datacenter Engineering Group Intel Corporation todd.fujin...@intel.com (503) 712-4565
-----Original Message----- From: Codrut Grosu [mailto:cogr...@ixiacom.com] Sent: Tuesday, August 1, 2017 8:30 AM To: e1000-devel@lists.sourceforge.net Subject: [E1000-devel] Possible bug in the i40evf driver Hi, We believe there might be a bug in the i40evf driver. We think that there is race issue between i40evf_reset_task and i40evf_down / i40evf_open. The reason is that the functions napi_enable / napi_disable must be called in pairs in order not to loop indefinitely (or crash). Consider the following: ifconfig eth1 mtu 1000 & ifconfig eth1 up What happens now is that the change of mtu schedules a reset. Suppose the reset task starts, and the first call to netif_running (after continue_reset) returns false. Before the thread reaches the second call to netif_running, i40evf_open starts in another thread. Then the second netif_running in reset will return true, and we will have 2 consecutive calls of napi_enable. We could not reproduce this particular situation in practice (probably due to the short timing). However, we did hang the driver using a call to ndo_close() followed quickly by "ethtool -G eth1 rx 4096". In this case netif_running will return true always (as we bypassed the call to dev_close), the reset will be scheduled before the interface finishes going down, and 2 calls to napi_disable will happen. Please let us know your opinion. Best wishes, Tudor, Codrut ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
