From 17f444c0549f2ce037646871e748cf2dc375bce9 Mon Sep 17 00:00:00 2001 From: Michael Bringmann Date: Fri, 8 Sep 2017 15:47:27 -0500 Subject: powerpc/vphn: Update CPU topology when VPHN enabled powerpc/vphn: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. This patch corrects the currently broken capability to set the topology for shared CPUs in LPARs. At boot time for shared CPU lpars, the topology for each CPU was being set to node zero. Now when numa_update_cpu_topology() is called appropriately, the Virtual Processor Home Node (VPHN) capabilities information provided by the pHyp allows the appropriate node in the shared configuration to be selected for the CPU. Signed-off-by: Michael Bringmann Signed-off-by: Michael Ellerman --- arch/powerpc/mm/numa.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/mm/numa.c') diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index b95c584ce19d..3ae031d437a6 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1153,6 +1153,8 @@ static cpumask_t cpu_associativity_changes_mask; static int vphn_enabled; static int prrn_enabled; static void reset_topology_timer(void); +static int topology_inited; +static int topology_update_needed; /* * Store the current values of the associativity change counters in the @@ -1246,6 +1248,10 @@ static long vphn_get_associativity(unsigned long cpu, "hcall_vphn() experienced a hardware fault " "preventing VPHN. Disabling polling...\n"); stop_topology_update(); + break; + case H_SUCCESS: + dbg("VPHN hcall succeeded. Reset polling...\n"); + break; } return rc; @@ -1323,8 +1329,11 @@ int numa_update_cpu_topology(bool cpus_locked) struct device *dev; int weight, new_nid, i = 0; - if (!prrn_enabled && !vphn_enabled) + if (!prrn_enabled && !vphn_enabled) { + if (!topology_inited) + topology_update_needed = 1; return 0; + } weight = cpumask_weight(&cpu_associativity_changes_mask); if (!weight) @@ -1363,6 +1372,8 @@ int numa_update_cpu_topology(bool cpus_locked) cpumask_andnot(&cpu_associativity_changes_mask, &cpu_associativity_changes_mask, cpu_sibling_mask(cpu)); + dbg("Assoc chg gives same node %d for cpu%d\n", + new_nid, cpu); cpu = cpu_last_thread_sibling(cpu); continue; } @@ -1433,6 +1444,7 @@ int numa_update_cpu_topology(bool cpus_locked) out: kfree(updates); + topology_update_needed = 0; return changed; } @@ -1613,9 +1625,17 @@ static int topology_update_init(void) if (topology_updates_enabled) start_topology_update(); + if (vphn_enabled) + topology_schedule_update(); + if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops)) return -ENOMEM; + topology_inited = 1; + if (topology_update_needed) + bitmap_fill(cpumask_bits(&cpu_associativity_changes_mask), + nr_cpumask_bits); + return 0; } device_initcall(topology_update_init); -- cgit v1.2.3 From a3496e9137f6f58439da29a761725e083229c4a8 Mon Sep 17 00:00:00 2001 From: Michael Bringmann Date: Fri, 8 Sep 2017 15:47:36 -0500 Subject: powerpc/vphn: Improve recognition of PRRN/VPHN powerpc/vphn: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. This patch updates the initialization checks to independently recognize PRRN or VPHN support. Signed-off-by: Michael Bringmann Signed-off-by: Michael Ellerman --- arch/powerpc/mm/numa.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/powerpc/mm/numa.c') diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 3ae031d437a6..5f5ff46ae76d 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1531,15 +1531,14 @@ int start_topology_update(void) if (firmware_has_feature(FW_FEATURE_PRRN)) { if (!prrn_enabled) { prrn_enabled = 1; - vphn_enabled = 0; #ifdef CONFIG_SMP rc = of_reconfig_notifier_register(&dt_update_nb); #endif } - } else if (firmware_has_feature(FW_FEATURE_VPHN) && + } + if (firmware_has_feature(FW_FEATURE_VPHN) && lppaca_shared_proc(get_lppaca())) { if (!vphn_enabled) { - prrn_enabled = 0; vphn_enabled = 1; setup_cpu_associativity_change_counters(); init_timer_deferrable(&topology_timer); @@ -1562,7 +1561,8 @@ int stop_topology_update(void) #ifdef CONFIG_SMP rc = of_reconfig_notifier_unregister(&dt_update_nb); #endif - } else if (vphn_enabled) { + } + if (vphn_enabled) { vphn_enabled = 0; rc = del_timer_sync(&topology_timer); } -- cgit v1.2.3 From cee5405da4020b0b0233bc8fb7c8da7322d2c52e Mon Sep 17 00:00:00 2001 From: Michael Bringmann Date: Fri, 8 Sep 2017 15:47:47 -0500 Subject: powerpc/hotplug: Improve responsiveness of hotplug change powerpc/hotplug: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. During hotplug CPU operations, this patch resets the timer on topology update work function to a small value to better ensure that the CPU topology is detected and configured sooner. Signed-off-by: Michael Bringmann Signed-off-by: Michael Ellerman --- arch/powerpc/mm/numa.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/mm/numa.c') diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 5f5ff46ae76d..32f5f8db46ec 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1148,14 +1148,34 @@ struct topology_update_data { int new_nid; }; +#define TOPOLOGY_DEF_TIMER_SECS 60 + static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS]; static cpumask_t cpu_associativity_changes_mask; static int vphn_enabled; static int prrn_enabled; static void reset_topology_timer(void); +static int topology_timer_secs = 1; static int topology_inited; static int topology_update_needed; +/* + * Change polling interval for associativity changes. + */ +int timed_topology_update(int nsecs) +{ + if (vphn_enabled) { + if (nsecs > 0) + topology_timer_secs = nsecs; + else + topology_timer_secs = TOPOLOGY_DEF_TIMER_SECS; + + reset_topology_timer(); + } + + return 0; +} + /* * Store the current values of the associativity change counters in the * hypervisor. @@ -1251,6 +1271,7 @@ static long vphn_get_associativity(unsigned long cpu, break; case H_SUCCESS: dbg("VPHN hcall succeeded. Reset polling...\n"); + timed_topology_update(0); break; } @@ -1481,7 +1502,7 @@ static struct timer_list topology_timer = static void reset_topology_timer(void) { topology_timer.data = 0; - topology_timer.expires = jiffies + 60 * HZ; + topology_timer.expires = jiffies + topology_timer_secs * HZ; mod_timer(&topology_timer, topology_timer.expires); } -- cgit v1.2.3 From 8bc931495d4bfcde6bb242a478ddd1186ae29301 Mon Sep 17 00:00:00 2001 From: Michael Bringmann Date: Fri, 8 Sep 2017 15:47:56 -0500 Subject: powerpc/vphn: Fix numa update end-loop bug powerpc/vphn: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. This patch fixes an end-of-updates processing problem observed occasionally in numa_update_cpu_topology(). Signed-off-by: Michael Bringmann Signed-off-by: Michael Ellerman --- arch/powerpc/mm/numa.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/mm/numa.c') diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 32f5f8db46ec..ec098b3f7332 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1401,16 +1401,22 @@ int numa_update_cpu_topology(bool cpus_locked) for_each_cpu(sibling, cpu_sibling_mask(cpu)) { ud = &updates[i++]; + ud->next = &updates[i]; ud->cpu = sibling; ud->new_nid = new_nid; ud->old_nid = numa_cpu_lookup_table[sibling]; cpumask_set_cpu(sibling, &updated_cpus); - if (i < weight) - ud->next = &updates[i]; } cpu = cpu_last_thread_sibling(cpu); } + /* + * Prevent processing of 'updates' from overflowing array + * where last entry filled in a 'next' pointer. + */ + if (i) + updates[i-1].next = NULL; + pr_debug("Topology update for the following CPUs:\n"); if (cpumask_weight(&updated_cpus)) { for (ud = &updates[0]; ud; ud = ud->next) { -- cgit v1.2.3