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To be specific when the user changes the mode to either "global_assign_ctrl_inherit_mon_per_cpu" or >>> "global_assign_ctrl_assign_mon_per_cpu" the new files will be created in the default resource group with >>> associated setting applied globally at that time. >> >> If, at that point, "info/kernel_mode_assignment" points to // (the default group), is that correct? > > I see "info/kernel_mode_assignment" pointing to default group as the only > option right after a mode switch away from "inherit_ctrl_and_mon". > > To elaborate, the current idea is that the mode within info/kernel_mode determines > which, if any, control files are presented to user space. > Assuming that the system boots up with: > # cat info/kernel_mode > [inherit_ctrl_and_mon] > global_assign_ctrl_inherit_mon_per_cpu > global_assign_ctrl_assign_mon_per_cpu > > In above scenario "info/kernel_mode_assignment" does not exist (is not visible to > user space). > > When the user switches to either "global_assign_ctrl_inherit_mon_per_cpu" or > 'global_assign_ctrl_assign_mon_per_cpu" then "info/kernel_mode_assignment" is created > (or made visible to user space) and is expected to point to default group. > User can change the group using "info/kernel_mode_assignment" at this point. > > If the current scenario is below ... > # cat info/kernel_mode > [global_assign_ctrl_inherit_mon_per_cpu] > inherit_ctrl_and_mon > global_assign_ctrl_assign_mon_per_cpu > > ... then "info/kernel_mode_assignment" will exist but what it should contain if > user switches mode at this point may be up for discussion. > > option 1) > When user switches mode to "global_assign_ctrl_assign_mon_per_cpu" then > the resource group in "info/kernel_mode_assignment" is reset to the > default group and all CPUs PLZA state reset to match. The kernel_mode_cpus > and kernel_mode_cpuslist files become visible in default resource group > and they contain "all online CPUs". > > option 2) > When user switches mode to "global_assign_ctrl_assign_mon_per_cpu" then > the resource group in "info/kernel_mode_assignment" is kept and all > CPUs PLZA state set to match it while also keeping the current > values of that resource group's kernel_mode_cpus and kernel_mode_cpuslist > files. > > I am leaning towards "option 1" to keep it consistent with a switch from > "inherit_ctrl_and_mon" and being deterministic about how a mode is started with Yes. The "option 1" seems appropriate. > a clean slate. What are your thoughts? What would be use case where a user would > want to switch between "global_assign_ctrl_inherit_mon_per_cpu" and > "global_assign_ctrl_assign_mon_per_cpu" to just switch rmid_en on and off? This is a bit tricky. Currently, our requirement is to have a CTRL_MON group for global_assign_ctrl_inherit_mon_per_cpu. In this scenario, we use the group’s CLOSID for PLZA configuration, and RMID is not used (rmid_en = 0) when setting up PLZA. Our requirement is also to have a CTRL_MON/MON group for global_assign_ctrl_assign_mon_per_cpu. In this case as well, the group’s CLOSID and RMID (rmid_en = 1) both are used configure PLZA. Actually, we should not allow these changes from global_assign_ctrl_inherit_mon_per_cpu to global_assign_ctrl_assign_mon_per_cpu or visa versa. This seems restrictive. > > >> And if "info/kernel_mode_assignment" points to a different group >> (for example, test//), then the kernel_mode_cpus/ and >> kernel_mode_cpus_list files will be created only under the test// >> group. Is that correct? > > I expect that if "info/kernel_mode_assignment" exists then the group > listed within contains kernel_mode_cpus and kernel_mode_cpuslist. > How the group ends up in "info/kernel_mode_assignment" could result > from mode change or from write by user space. > Ack. Thanks Babu>