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Being specific > and consistent with terms would make this so much easier to understand. I avoided using CLOSID and RMID terms in filesystem specific code. If you are ok with that then I will use these terms. > >> kernel mode. The mode is enabled/disabled on a per-CPU basis. >> >> Add kmode_cpus and kmode_cpus_list to display the CPUs associated with a >> kernel mode. These files are exposed only when the global_enable_per_cpu > > > "a kernel mode" -> this is specific to RESCTRL_GLOBAL_ENABLE_PER_CPU kernel > mode node? Sure. > > This switches from "RESCTRL_GLOBAL_ENABLE_PER_CPU kernel mode" to > "global_enable_per_cpu mode" mid changelog. Will change it. > >> mode is active. >> >> Signed-off-by: Babu Moger >> --- > > ...> --- >> fs/resctrl/internal.h | 2 ++ >> fs/resctrl/rdtgroup.c | 42 ++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 44 insertions(+) >> >> diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h >> index 986b9c942fb2..6b8d14c4bd83 100644 >> --- a/fs/resctrl/internal.h >> +++ b/fs/resctrl/internal.h >> @@ -216,6 +216,7 @@ struct mongroup { >> * @mon: mongroup related data >> * @mode: mode of resource group >> * @mba_mbps_event: input monitoring event id when mba_sc is enabled >> + * @kmode_cpu_mask: CPUs in this group's kernel-mode association > > Could there be a caveat that the value is only valid when the resource group > is backing the RESCTRL_GLOBAL_ENABLE_PER_CPU kernel mode? Sure. > >> * @plr: pseudo-locked region >> */ >> struct rdtgroup { >> @@ -229,6 +230,7 @@ struct rdtgroup { >> struct mongroup mon; >> enum rdtgrp_mode mode; >> enum resctrl_event_id mba_mbps_event; >> + struct cpumask kmode_cpu_mask; >> struct pseudo_lock_region *plr; >> }; >> >> diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c >> index 46b2cafd9411..0e638dc654c1 100644 >> --- a/fs/resctrl/rdtgroup.c >> +++ b/fs/resctrl/rdtgroup.c >> @@ -385,6 +385,31 @@ static int rdtgroup_cpus_show(struct kernfs_open_file *of, >> return ret; >> } >> >> +/* >> + * Display CPU masks for the kernel-mode associated resource group. > > nit: "masks for" -> "mask of"? Sure. > >> + * Supports both "kmode_cpus" (bitmap format) and "kmode_cpus_list" >> + * (range list format); the output format is selected accordingly. >> + * >> + * Returns -ENOENT on error. >> + */ >> +static int rdtgroup_kmode_cpus_show(struct kernfs_open_file *of, >> + struct seq_file *s, void *v) >> +{ >> + struct rdtgroup *rdtgrp; >> + int ret = 0; >> + >> + rdtgrp = rdtgroup_kn_lock_live(of->kn); >> + >> + if (!rdtgrp || rdtgrp != resctrl_kmode.rdtgrp) > > Could the changelog please help reader understand the patches better? > For example, the additional "rdtgrp != resctrl_kmode.rdtgrp" check is > subtle but very important to maintain synchronization, but it is > never mentioned why this is used. Will add a line in changelog about this check. Thanks Babu