Hi Christoph, The only way to query coalesce options is via the "ethtool -c" command. I don't know if it helps you, but are you familiar with the driver param: InterruptThrottleRate. Run: "modinfo e1000e" command, and you can also look at the param.c file.
Thanks, Raanan -----Original Message----- From: Christoph Mathys [mailto:erase...@gmail.com] Sent: Tuesday, October 27, 2015 17:00 To: e1000-devel@lists.sourceforge.net Subject: [E1000-devel] [e1000e] Mismatch between coalesce settings from ethtool and effective settings? Hi there Is there some way to read the actual values for the coalesce options back from the NIC? To be specific, I'm interested in the value of ITR on a 82574L chip. I suspect it does not match with the value that I get from "ethtool -c". Reading back from userspace, without compiling a lot of stuff if possible... Some background: I use ifupdown from Debian to configure an Ethernet interface. I want to disable all coalesce settings. What I've done is to call ethtool with the required parameter from a script in if-up.d, which is run right after the interface gets set to up (using something like ifconfig up). However, judging from my applications behaviour I think that the default "rx-usecs 3" is still active, even though ethtool -c tells me it is set to '0'. After changing it to "1" and then back to "0", my application works properly (change to one is required because ethtool will not write the same value again). I suspect some kind of race between the kernel thread bringing up the interface and my script calling ethtool, and I hope to verify this by seeing the actual values of coalesce that are used. I use a dated 3.12 with PREEMPT_RT patch. Christoph PS Please CC ------------------------------------------------------------------------------ _______________________________________________ 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 --------------------------------------------------------------------- Intel Israel (74) Limited This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. ------------------------------------------------------------------------------ _______________________________________________ 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
