x86/resctrl: Preserve CDP enable over CPU hotplug

commit 9fe0450785 upstream.

Resctrl assumes that all CPUs are online when the filesystem is mounted,
and that CPUs remember their CDP-enabled state over CPU hotplug.

This goes wrong when resctrl's CDP-enabled state changes while all the
CPUs in a domain are offline.

When a domain comes online, enable (or disable!) CDP to match resctrl's
current setting.

Fixes: 5ff193fbde ("x86/intel_rdt: Add basic resctrl filesystem support")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200221162105.154163-1-james.morse@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
James Morse 2020-02-21 16:21:05 +00:00 committed by Greg Kroah-Hartman
parent 9da6458d7f
commit e7e08add4b
3 changed files with 16 additions and 0 deletions

View file

@ -555,6 +555,8 @@ static void domain_add_cpu(int cpu, struct rdt_resource *r)
d->id = id;
cpumask_set_cpu(cpu, &d->cpu_mask);
rdt_domain_reconfigure_cdp(r);
if (r->alloc_capable && domain_setup_ctrlval(r, d)) {
kfree(d);
return;

View file

@ -567,5 +567,6 @@ void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms);
void cqm_handle_limbo(struct work_struct *work);
bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d);
void __check_limbo(struct rdt_domain *d, bool force_free);
void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
#endif /* _ASM_X86_INTEL_RDT_H */

View file

@ -1777,6 +1777,19 @@ static int set_cache_qos_cfg(int level, bool enable)
return 0;
}
/* Restore the qos cfg state when a domain comes online */
void rdt_domain_reconfigure_cdp(struct rdt_resource *r)
{
if (!r->alloc_capable)
return;
if (r == &rdt_resources_all[RDT_RESOURCE_L2DATA])
l2_qos_cfg_update(&r->alloc_enabled);
if (r == &rdt_resources_all[RDT_RESOURCE_L3DATA])
l3_qos_cfg_update(&r->alloc_enabled);
}
/*
* Enable or disable the MBA software controller
* which helps user specify bandwidth in MBps.