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linux-stable/arch/x86/kernel/cpu/resctrl
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Babu Moger 064855a690 x86/resctrl: Fix default monitoring groups reporting 
Creating a new sub monitoring group in the root /sys/fs/resctrl leads to
getting the "Unavailable" value for mbm_total_bytes and mbm_local_bytes
on the entire filesystem.

Steps to reproduce:

  1. mount -t resctrl resctrl /sys/fs/resctrl/

  2. cd /sys/fs/resctrl/

  3. cat mon_data/mon_L3_00/mbm_total_bytes
     23189832

  4. Create sub monitor group:
  mkdir mon_groups/test1

  5. cat mon_data/mon_L3_00/mbm_total_bytes
     Unavailable

When a new monitoring group is created, a new RMID is assigned to the
new group. But the RMID is not active yet. When the events are read on
the new RMID, it is expected to report the status as "Unavailable".

When the user reads the events on the default monitoring group with
multiple subgroups, the events on all subgroups are consolidated
together. Currently, if any of the RMID reads report as "Unavailable",
then everything will be reported as "Unavailable".

Fix the issue by discarding the "Unavailable" reads and reporting all
the successful RMID reads. This is not a problem on Intel systems as
Intel reports 0 on Inactive RMIDs.

Fixes: d89b737901 ("x86/intel_rdt/cqm: Add mon_data")
Reported-by: Paweł Szulik <pawel.szulik@intel.com>
Signed-off-by: Babu Moger <Babu.Moger@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=213311
Link: https://lkml.kernel.org/r/162793309296.9224.15871659871696482080.stgit@bmoger-ubuntu
2021-08-12 20:12:20 +02:00
..
core.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
ctrlmondata.c x86/resctrl: Add struct rdt_cache::arch_has_{sparse, empty}_bitmaps 2020-08-19 10:41:40 +02:00
internal.h x86/resctrl: Fix kernel-doc in internal.h 2021-06-24 10:23:57 +02:00
Makefile x86/resctrl: Avoid confusion over the new X86_RESCTRL config 2019-02-02 10:34:52 +01:00
monitor.c x86/resctrl: Fix default monitoring groups reporting 2021-08-12 20:12:20 +02:00
pseudo_lock.c x86/resctrl: Fix kernel-doc in pseudo_lock.c 2021-06-24 10:21:05 +02:00
pseudo_lock_event.h
rdtgroup.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00