>> case Opt_mba_mbps: >> if (!supports_mba_mbps() || ctx->enable_mba_mbps) >> return -EINVAL; > > I am not familiar with the API but it seems that invalfc() is available > to communicate a more useful message to user space than the default one > shown in changelog of patch #2. I experimented with invalfc(). It seems to be the answer to this part of the mount error message: dmesg(1) may have more information after failed mount system call. because dmesg(1) does indeed include whatever message that is provided by the invalfc() call (including automatically adding the prefix "resctrl: "). I'll work on incorporating your other feedback, but I'm unlikely to get it all done and tested before the end of this week. I'll be on vacation the last two weeks of the year. So v7 of this series will have to wait until 2024. Thanks -Tony