Hi Babu, On 8/6/24 3:00 PM, Babu Moger wrote:
The ABMC feature provides an option to the user to assign a hardware
Here and in all patches, when referring to resctrl fs please use the more generic "mbm_assign_cntr" mode to distinguish it from the hardware/architecture specific code that involves ABMC. Something like "The ABMC feature provides" -> ""mbm_cntr_assign" mode provides" I also think that being explicit with this separation will help us to see gaps in interface between resctrl fs and arch.
counter to an RMID and monitor the bandwidth as long as the counter is
Please clarify the scope of this feature. Above mentions that a counter is assigned to an RMID but later it is mentioned that the counter is assigned to an event. Perhaps consistently mention that a counter is assigned to a RMID,event pair?
assigned. Number of assignments depend on number of monitoring counters available. Provide the interface to display the number of monitoring counters supported. Signed-off-by: Babu Moger <babu.moger@xxxxxxx> --- v6: No changes. v5: Changed the display name from num_cntrs to num_mbm_cntrs. Updated the commit message. Moved the patch after mbm_mode is introduced. v4: Changed the counter name to num_cntrs. And few text changes. v3: Changed the field name to mbm_assign_cntrs. v2: Changed the field name to mbm_assignable_counters from abmc_counte --- Documentation/arch/x86/resctrl.rst | 3 +++ arch/x86/kernel/cpu/resctrl/monitor.c | 2 ++ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 ++++++++++++++++ 3 files changed, 21 insertions(+) diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst index d4ec605b200a..fe9f10766c4f 100644 --- a/Documentation/arch/x86/resctrl.rst +++ b/Documentation/arch/x86/resctrl.rst @@ -291,6 +291,9 @@ with the following files: as long as there are enough RMID counters available to support number of monitoring groups.+"num_mbm_cntrs":+ The number of monitoring counters available for assignment. + "max_threshold_occupancy": Read/write file provides the largest value (in bytes) at which a previously used LLC_occupancy diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 5e8706ab6361..83329cefebf7 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -1242,6 +1242,8 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) r->mon.num_mbm_cntrs = (ebx & 0xFFFF) + 1; if (WARN_ON(r->mon.num_mbm_cntrs > 64)) r->mon.num_mbm_cntrs = 64; + + resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO);
The arch code should not access the resctrl file flags. This should be moved to make the MPAM support easier. With the arch code setting r->mon.mbm_cntr_assignable the fs code can use that to set the flags. Something similar to below patch is needed: https://lore.kernel.org/lkml/20240802172853.22529-27-james.morse@xxxxxxx/
} }
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