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Commit e7e08add authored by James Morse's avatar James Morse Committed by Greg Kroah-Hartman
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x86/resctrl: Preserve CDP enable over CPU hotplug 



commit 9fe0450785abbc04b0ed5d3cf61fcdb8ab656b4b 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: 5ff193fb ("x86/intel_rdt: Add basic resctrl filesystem support")
Suggested-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarBorislav 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: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9da6458d

arch/x86/kernel/cpu/intel_rdt.c

+2 −0
Original line number Diff line number Diff line
@@ -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;

arch/x86/kernel/cpu/intel_rdt.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

arch/x86/kernel/cpu/intel_rdt_rdtgroup.c

+13 −0
Original line number Diff line number Diff line
@@ -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.