Commit c8c7d3d9 authored by Tony Luck's avatar Tony Luck Committed by Borislav Petkov (AMD)
Browse files

x86/resctrl: Fill out rmid_read structure for smp_call*() to read a counter 



mon_event_read() fills out most fields of the struct rmid_read that is passed
via an smp_call*() function to a CPU that is part of the correct domain to
read the monitor counters.

With Sub-NUMA Cluster (SNC) mode there are now two cases to handle:

1) Reading a file that returns a value for a single domain.
   + Choose the CPU to execute from the domain cpu_mask

2) Reading a file that must sum across domains sharing an L3 cache
   instance.
   + Indicate to called code that a sum is needed by passing a NULL
     rdt_mon_domain pointer.
   + Choose the CPU from the L3 shared_cpu_map.

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Tested-by: default avatarBabu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-16-tony.luck@intel.com
parent 6b48b80b

arch/x86/kernel/cpu/resctrl/ctrlmondata.c

+32 −8
Original line number Diff line number Diff line
@@ -515,7 +515,7 @@ static int smp_mon_event_count(void *arg) 


void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,

		    struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,

		    int evtid, int first)

		    cpumask_t *cpumask, int evtid, int first)

{

	int cpu;
@@ -536,7 +536,7 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, 
		return;

	}



	cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask, RESCTRL_PICK_ANY_CPU);

	cpu = cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU);



	/*

	 * cpumask_any_housekeeping() prefers housekeeping CPUs, but
@@ -545,7 +545,7 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, 
	 * counters on some platforms if its called in IRQ context.

	 */

	if (tick_nohz_full_cpu(cpu))

		smp_call_function_any(&d->hdr.cpu_mask, mon_event_count, rr, 1);

		smp_call_function_any(cpumask, mon_event_count, rr, 1);

	else

		smp_call_on_cpu(cpu, smp_mon_event_count, rr, false);
@@ -574,16 +574,40 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) 
	resid = md.u.rid;

	domid = md.u.domid;

	evtid = md.u.evtid;



	r = &rdt_resources_all[resid].r_resctrl;



	if (md.u.sum) {

		/*

		 * This file requires summing across all domains that share

		 * the L3 cache id that was provided in the "domid" field of the

		 * mon_data_bits union. Search all domains in the resource for

		 * one that matches this cache id.

		 */

		list_for_each_entry(d, &r->mon_domains, hdr.list) {

			if (d->ci->id == domid) {

				rr.ci = d->ci;

				mon_event_read(&rr, r, NULL, rdtgrp,

					       &d->ci->shared_cpu_map, evtid, false);

				goto checkresult;

			}

		}

		ret = -ENOENT;

		goto out;

	} else {

		/*

		 * This file provides data from a single domain. Search

		 * the resource to find the domain with "domid".

		 */

		hdr = rdt_find_domain(&r->mon_domains, domid, NULL);

		if (!hdr || WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) {

			ret = -ENOENT;

			goto out;

		}

		d = container_of(hdr, struct rdt_mon_domain, hdr);

		mon_event_read(&rr, r, d, rdtgrp, &d->hdr.cpu_mask, evtid, false);

	}



	mon_event_read(&rr, r, d, rdtgrp, evtid, false);

checkresult:



	if (rr.err == -EIO)

		seq_puts(m, "Error\n");

arch/x86/kernel/cpu/resctrl/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -632,7 +632,7 @@ void mon_event_count(void *info); 
int rdtgroup_mondata_show(struct seq_file *m, void *arg);

void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,

		    struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,

		    int evtid, int first);

		    cpumask_t *cpumask, int evtid, int first);

void mbm_setup_overflow_handler(struct rdt_mon_domain *dom,

				unsigned long delay_ms,

				int exclude_cpu);

arch/x86/kernel/cpu/resctrl/rdtgroup.c

+1 −1
Original line number Diff line number Diff line
@@ -3070,7 +3070,7 @@ static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d, 
			return ret;



		if (!do_sum && is_mbm_event(mevt->evtid))

			mon_event_read(&rr, r, d, prgrp, mevt->evtid, true);

			mon_event_read(&rr, r, d, prgrp, &d->hdr.cpu_mask, mevt->evtid, true);

	}



	return 0;