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author | Jesse Larrew <jlarrew@linux.vnet.ibm.com> | 2013-04-24 06:00:35 +0000 |
---|---|---|
committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-04-26 16:08:23 +1000 |
commit | 5d88aa85c00bb4026dd986430dc496effc637d42 (patch) | |
tree | 206edc195104eb8258a36b25f5247055211164c2 /arch/powerpc/mm/numa.c | |
parent | 8002b0c54b16931ad71771e6c97e46aca1be4456 (diff) | |
download | op-kernel-dev-5d88aa85c00bb4026dd986430dc496effc637d42.zip op-kernel-dev-5d88aa85c00bb4026dd986430dc496effc637d42.tar.gz |
powerpc/pseries: Update CPU maps when device tree is updated
Platform events such as partition migration or the new PRRN firmware
feature can cause the NUMA characteristics of a CPU to change, and these
changes will be reflected in the device tree nodes for the affected
CPUs.
This patch registers a handler for Open Firmware device tree updates
and reconfigures the CPU and node maps whenever the associativity
changes. Currently, this is accomplished by marking the affected CPUs in
the cpu_associativity_changes_mask and allowing
arch_update_cpu_topology() to retrieve the new associativity information
using hcall_vphn().
Protecting the NUMA cpu maps from concurrent access during an update
operation will be addressed in a subsequent patch in this series.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/mm/numa.c')
-rw-r--r-- | arch/powerpc/mm/numa.c | 99 |
1 files changed, 75 insertions, 24 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 4cee835..42f50c3 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1257,7 +1257,8 @@ u64 memory_hotplug_max(void) static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS]; static cpumask_t cpu_associativity_changes_mask; static int vphn_enabled; -static void set_topology_timer(void); +static int prrn_enabled; +static void reset_topology_timer(void); /* * Store the current values of the associativity change counters in the @@ -1293,11 +1294,9 @@ static void setup_cpu_associativity_change_counters(void) */ static int update_cpu_associativity_changes_mask(void) { - int cpu, nr_cpus = 0; + int cpu; cpumask_t *changes = &cpu_associativity_changes_mask; - cpumask_clear(changes); - for_each_possible_cpu(cpu) { int i, changed = 0; u8 *counts = vphn_cpu_change_counts[cpu]; @@ -1311,11 +1310,10 @@ static int update_cpu_associativity_changes_mask(void) } if (changed) { cpumask_set_cpu(cpu, changes); - nr_cpus++; } } - return nr_cpus; + return cpumask_weight(changes); } /* @@ -1416,7 +1414,7 @@ int arch_update_cpu_topology(void) unsigned int associativity[VPHN_ASSOC_BUFSIZE] = {0}; struct device *dev; - for_each_cpu(cpu,&cpu_associativity_changes_mask) { + for_each_cpu(cpu, &cpu_associativity_changes_mask) { vphn_get_associativity(cpu, associativity); nid = associativity_to_nid(associativity); @@ -1438,6 +1436,7 @@ int arch_update_cpu_topology(void) dev = get_cpu_device(cpu); if (dev) kobject_uevent(&dev->kobj, KOBJ_CHANGE); + cpumask_clear_cpu(cpu, &cpu_associativity_changes_mask); changed = 1; } @@ -1457,37 +1456,80 @@ void topology_schedule_update(void) static void topology_timer_fn(unsigned long ignored) { - if (!vphn_enabled) - return; - if (update_cpu_associativity_changes_mask() > 0) + if (prrn_enabled && cpumask_weight(&cpu_associativity_changes_mask)) topology_schedule_update(); - set_topology_timer(); + else if (vphn_enabled) { + if (update_cpu_associativity_changes_mask() > 0) + topology_schedule_update(); + reset_topology_timer(); + } } static struct timer_list topology_timer = TIMER_INITIALIZER(topology_timer_fn, 0, 0); -static void set_topology_timer(void) +static void reset_topology_timer(void) { topology_timer.data = 0; topology_timer.expires = jiffies + 60 * HZ; - add_timer(&topology_timer); + mod_timer(&topology_timer, topology_timer.expires); +} + +static void stage_topology_update(int core_id) +{ + cpumask_or(&cpu_associativity_changes_mask, + &cpu_associativity_changes_mask, cpu_sibling_mask(core_id)); + reset_topology_timer(); +} + +static int dt_update_callback(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct of_prop_reconfig *update; + int rc = NOTIFY_DONE; + + switch (action) { + case OF_RECONFIG_ADD_PROPERTY: + case OF_RECONFIG_UPDATE_PROPERTY: + update = (struct of_prop_reconfig *)data; + if (!of_prop_cmp(update->dn->type, "cpu")) { + u32 core_id; + of_property_read_u32(update->dn, "reg", &core_id); + stage_topology_update(core_id); + rc = NOTIFY_OK; + } + break; + } + + return rc; } +static struct notifier_block dt_update_nb = { + .notifier_call = dt_update_callback, +}; + /* - * Start polling for VPHN associativity changes. + * Start polling for associativity changes. */ int start_topology_update(void) { int rc = 0; - /* Disabled until races with load balancing are fixed */ - if (0 && firmware_has_feature(FW_FEATURE_VPHN) && - get_lppaca()->shared_proc) { - vphn_enabled = 1; - setup_cpu_associativity_change_counters(); - init_timer_deferrable(&topology_timer); - set_topology_timer(); - rc = 1; + if (firmware_has_feature(FW_FEATURE_PRRN)) { + if (!prrn_enabled) { + prrn_enabled = 1; + vphn_enabled = 0; + rc = of_reconfig_notifier_register(&dt_update_nb); + } + } else if (0 && firmware_has_feature(FW_FEATURE_VPHN) && + get_lppaca()->shared_proc) { + /* Disabled until races with load balancing are fixed */ + if (!vphn_enabled) { + prrn_enabled = 0; + vphn_enabled = 1; + setup_cpu_associativity_change_counters(); + init_timer_deferrable(&topology_timer); + reset_topology_timer(); + } } return rc; @@ -1499,7 +1541,16 @@ __initcall(start_topology_update); */ int stop_topology_update(void) { - vphn_enabled = 0; - return del_timer_sync(&topology_timer); + int rc = 0; + + if (prrn_enabled) { + prrn_enabled = 0; + rc = of_reconfig_notifier_unregister(&dt_update_nb); + } else if (vphn_enabled) { + vphn_enabled = 0; + rc = del_timer_sync(&topology_timer); + } + + return rc; } #endif /* CONFIG_PPC_SPLPAR */ |