The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 87d3aa28f345bea77c396855fa5d5fec4c24461f Mon Sep 17 00:00:00 2001
From: James Morse james.morse@arm.com Date: Mon, 3 Jun 2019 18:25:31 +0100 Subject: [PATCH] x86/resctrl: Don't stop walking closids when a locksetup group is found
When a new control group is created __init_one_rdt_domain() walks all the other closids to calculate the sets of used and unused bits.
If it discovers a pseudo_locksetup group, it breaks out of the loop. This means any later closid doesn't get its used bits added to used_b. These bits will then get set in unused_b, and added to the new control group's configuration, even if they were marked as exclusive for a later closid.
When encountering a pseudo_locksetup group, we should continue. This is because "a resource group enters 'pseudo-locked' mode after the schemata is written while the resource group is in 'pseudo-locksetup' mode." When we find a pseudo_locksetup group, its configuration is expected to be overwritten, we can skip it.
Fixes: dfe9674b04ff6 ("x86/intel_rdt: Enable entering of pseudo-locksetup mode") Signed-off-by: James Morse james.morse@arm.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Reinette Chatre reinette.chatre@intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: Borislav Petkov bp@alien8.de Cc: H Peter Avin hpa@zytor.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190603172531.178830-1-james.morse@arm.com
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 333c177a2471..869cbef5da81 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2542,7 +2542,12 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct rdt_resource *r, if (closid_allocated(i) && i != closid) { mode = rdtgroup_mode_by_closid(i); if (mode == RDT_MODE_PSEUDO_LOCKSETUP) - break; + /* + * ctrl values for locksetup aren't relevant + * until the schemata is written, and the mode + * becomes RDT_MODE_PSEUDO_LOCKED. + */ + continue; /* * If CDP is active include peer domain's * usage to ensure there is no overlap