MODULE_PARM_DESC(memmap_on_memory, "Enable memmap on memory for memory hotplug");
#endif
+enum {
+ ONLINE_POLICY_CONTIG_ZONES = 0,
+ ONLINE_POLICY_AUTO_MOVABLE,
+};
+
+const char *online_policy_to_str[] = {
+ [ONLINE_POLICY_CONTIG_ZONES] = "contig-zones",
+ [ONLINE_POLICY_AUTO_MOVABLE] = "auto-movable",
+};
+
+static int set_online_policy(const char *val, const struct kernel_param *kp)
+{
+ int ret = sysfs_match_string(online_policy_to_str, val);
+
+ if (ret < 0)
+ return ret;
+ *((int *)kp->arg) = ret;
+ return 0;
+}
+
+static int get_online_policy(char *buffer, const struct kernel_param *kp)
+{
+ return sprintf(buffer, "%s\n", online_policy_to_str[*((int *)kp->arg)]);
+}
+
+/*
+ * memory_hotplug.online_policy: configure online behavior when onlining without
+ * specifying a zone (MMOP_ONLINE)
+ *
+ * "contig-zones": keep zone contiguous
+ * "auto-movable": online memory to ZONE_MOVABLE if the configuration
+ * (auto_movable_ratio, auto_movable_numa_aware) allows for it
+ */
+static int online_policy __read_mostly = ONLINE_POLICY_CONTIG_ZONES;
+static const struct kernel_param_ops online_policy_ops = {
+ .set = set_online_policy,
+ .get = get_online_policy,
+};
+module_param_cb(online_policy, &online_policy_ops, &online_policy, 0644);
+MODULE_PARM_DESC(online_policy,
+ "Set the online policy (\"contig-zones\", \"auto-movable\") "
+ "Default: \"contig-zones\"");
+
+/*
+ * memory_hotplug.auto_movable_ratio: specify maximum MOVABLE:KERNEL ratio
+ *
+ * The ratio represent an upper limit and the kernel might decide to not
+ * online some memory to ZONE_MOVABLE -- e.g., because hotplugged KERNEL memory
+ * doesn't allow for more MOVABLE memory.
+ */
+static unsigned int auto_movable_ratio __read_mostly = 301;
+module_param(auto_movable_ratio, uint, 0644);
+MODULE_PARM_DESC(auto_movable_ratio,
+ "Set the maximum ratio of MOVABLE:KERNEL memory in the system "
+ "in percent for \"auto-movable\" online policy. Default: 301");
+
+/*
+ * memory_hotplug.auto_movable_numa_aware: consider numa node stats
+ */
+#ifdef CONFIG_NUMA
+static bool auto_movable_numa_aware __read_mostly = true;
+module_param(auto_movable_numa_aware, bool, 0644);
+MODULE_PARM_DESC(auto_movable_numa_aware,
+ "Consider numa node stats in addition to global stats in "
+ "\"auto-movable\" online policy. Default: true");
+#endif /* CONFIG_NUMA */
+
/*
* online_page_callback contains pointer to current page onlining function.
* Initially it is generic_online_page(). If it is required it could be
sizeof(struct page) * cur_nr_pages);
}
-#ifdef CONFIG_ZONE_DEVICE
/*
* Zone shrinking code cannot properly deal with ZONE_DEVICE. So
* we will not try to shrink the zones - which is okay as
* set_zone_contiguous() cannot deal with ZONE_DEVICE either way.
*/
- if (zone_idx(zone) == ZONE_DEVICE)
+ if (zone_is_zone_device(zone))
return;
-#endif
clear_zone_contiguous(zone);
set_zone_contiguous(zone);
}
+struct auto_movable_stats {
+ unsigned long kernel_early_pages;
+ unsigned long movable_pages;
+};
+
+static void auto_movable_stats_account_zone(struct auto_movable_stats *stats,
+ struct zone *zone)
+{
+ if (zone_idx(zone) == ZONE_MOVABLE) {
+ stats->movable_pages += zone->present_pages;
+ } else {
+ stats->kernel_early_pages += zone->present_early_pages;
+#ifdef CONFIG_CMA
+ /*
+ * CMA pages (never on hotplugged memory) behave like
+ * ZONE_MOVABLE.
+ */
+ stats->movable_pages += zone->cma_pages;
+ stats->kernel_early_pages -= zone->cma_pages;
+#endif /* CONFIG_CMA */
+ }
+}
+struct auto_movable_group_stats {
+ unsigned long movable_pages;
+ unsigned long req_kernel_early_pages;
+};
+
+static int auto_movable_stats_account_group(struct memory_group *group,
+ void *arg)
+{
+ const int ratio = READ_ONCE(auto_movable_ratio);
+ struct auto_movable_group_stats *stats = arg;
+ long pages;
+
+ /*
+ * We don't support modifying the config while the auto-movable online
+ * policy is already enabled. Just avoid the division by zero below.
+ */
+ if (!ratio)
+ return 0;
+
+ /*
+ * Calculate how many early kernel pages this group requires to
+ * satisfy the configured zone ratio.
+ */
+ pages = group->present_movable_pages * 100 / ratio;
+ pages -= group->present_kernel_pages;
+
+ if (pages > 0)
+ stats->req_kernel_early_pages += pages;
+ stats->movable_pages += group->present_movable_pages;
+ return 0;
+}
+
+static bool auto_movable_can_online_movable(int nid, struct memory_group *group,
+ unsigned long nr_pages)
+{
+ unsigned long kernel_early_pages, movable_pages;
+ struct auto_movable_group_stats group_stats = {};
+ struct auto_movable_stats stats = {};
+ pg_data_t *pgdat = NODE_DATA(nid);
+ struct zone *zone;
+ int i;
+
+ /* Walk all relevant zones and collect MOVABLE vs. KERNEL stats. */
+ if (nid == NUMA_NO_NODE) {
+ /* TODO: cache values */
+ for_each_populated_zone(zone)
+ auto_movable_stats_account_zone(&stats, zone);
+ } else {
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ zone = pgdat->node_zones + i;
+ if (populated_zone(zone))
+ auto_movable_stats_account_zone(&stats, zone);
+ }
+ }
+
+ kernel_early_pages = stats.kernel_early_pages;
+ movable_pages = stats.movable_pages;
+
+ /*
+ * Kernel memory inside dynamic memory group allows for more MOVABLE
+ * memory within the same group. Remove the effect of all but the
+ * current group from the stats.
+ */
+ walk_dynamic_memory_groups(nid, auto_movable_stats_account_group,
+ group, &group_stats);
+ if (kernel_early_pages <= group_stats.req_kernel_early_pages)
+ return false;
+ kernel_early_pages -= group_stats.req_kernel_early_pages;
+ movable_pages -= group_stats.movable_pages;
+
+ if (group && group->is_dynamic)
+ kernel_early_pages += group->present_kernel_pages;
+
+ /*
+ * Test if we could online the given number of pages to ZONE_MOVABLE
+ * and still stay in the configured ratio.
+ */
+ movable_pages += nr_pages;
+ return movable_pages <= (auto_movable_ratio * kernel_early_pages) / 100;
+}
+
/*
* Returns a default kernel memory zone for the given pfn range.
* If no kernel zone covers this pfn range it will automatically go
return &pgdat->node_zones[ZONE_NORMAL];
}
+/*
+ * Determine to which zone to online memory dynamically based on user
+ * configuration and system stats. We care about the following ratio:
+ *
+ * MOVABLE : KERNEL
+ *
+ * Whereby MOVABLE is memory in ZONE_MOVABLE and KERNEL is memory in
+ * one of the kernel zones. CMA pages inside one of the kernel zones really
+ * behaves like ZONE_MOVABLE, so we treat them accordingly.
+ *
+ * We don't allow for hotplugged memory in a KERNEL zone to increase the
+ * amount of MOVABLE memory we can have, so we end up with:
+ *
+ * MOVABLE : KERNEL_EARLY
+ *
+ * Whereby KERNEL_EARLY is memory in one of the kernel zones, available sinze
+ * boot. We base our calculation on KERNEL_EARLY internally, because:
+ *
+ * a) Hotplugged memory in one of the kernel zones can sometimes still get
+ * hotunplugged, especially when hot(un)plugging individual memory blocks.
+ * There is no coordination across memory devices, therefore "automatic"
+ * hotunplugging, as implemented in hypervisors, could result in zone
+ * imbalances.
+ * b) Early/boot memory in one of the kernel zones can usually not get
+ * hotunplugged again (e.g., no firmware interface to unplug, fragmented
+ * with unmovable allocations). While there are corner cases where it might
+ * still work, it is barely relevant in practice.
+ *
+ * Exceptions are dynamic memory groups, which allow for more MOVABLE
+ * memory within the same memory group -- because in that case, there is
+ * coordination within the single memory device managed by a single driver.
+ *
+ * We rely on "present pages" instead of "managed pages", as the latter is
+ * highly unreliable and dynamic in virtualized environments, and does not
+ * consider boot time allocations. For example, memory ballooning adjusts the
+ * managed pages when inflating/deflating the balloon, and balloon compaction
+ * can even migrate inflated pages between zones.
+ *
+ * Using "present pages" is better but some things to keep in mind are:
+ *
+ * a) Some memblock allocations, such as for the crashkernel area, are
+ * effectively unused by the kernel, yet they account to "present pages".
+ * Fortunately, these allocations are comparatively small in relevant setups
+ * (e.g., fraction of system memory).
+ * b) Some hotplugged memory blocks in virtualized environments, esecially
+ * hotplugged by virtio-mem, look like they are completely present, however,
+ * only parts of the memory block are actually currently usable.
+ * "present pages" is an upper limit that can get reached at runtime. As
+ * we base our calculations on KERNEL_EARLY, this is not an issue.
+ */
+static struct zone *auto_movable_zone_for_pfn(int nid,
+ struct memory_group *group,
+ unsigned long pfn,
+ unsigned long nr_pages)
+{
+ unsigned long online_pages = 0, max_pages, end_pfn;
+ struct page *page;
+
+ if (!auto_movable_ratio)
+ goto kernel_zone;
+
+ if (group && !group->is_dynamic) {
+ max_pages = group->s.max_pages;
+ online_pages = group->present_movable_pages;
+
+ /* If anything is !MOVABLE online the rest !MOVABLE. */
+ if (group->present_kernel_pages)
+ goto kernel_zone;
+ } else if (!group || group->d.unit_pages == nr_pages) {
+ max_pages = nr_pages;
+ } else {
+ max_pages = group->d.unit_pages;
+ /*
+ * Take a look at all online sections in the current unit.
+ * We can safely assume that all pages within a section belong
+ * to the same zone, because dynamic memory groups only deal
+ * with hotplugged memory.
+ */
+ pfn = ALIGN_DOWN(pfn, group->d.unit_pages);
+ end_pfn = pfn + group->d.unit_pages;
+ for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ page = pfn_to_online_page(pfn);
+ if (!page)
+ continue;
+ /* If anything is !MOVABLE online the rest !MOVABLE. */
+ if (page_zonenum(page) != ZONE_MOVABLE)
+ goto kernel_zone;
+ online_pages += PAGES_PER_SECTION;
+ }
+ }
+
+ /*
+ * Online MOVABLE if we could *currently* online all remaining parts
+ * MOVABLE. We expect to (add+) online them immediately next, so if
+ * nobody interferes, all will be MOVABLE if possible.
+ */
+ nr_pages = max_pages - online_pages;
+ if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages))
+ goto kernel_zone;
+
+#ifdef CONFIG_NUMA
+ if (auto_movable_numa_aware &&
+ !auto_movable_can_online_movable(nid, group, nr_pages))
+ goto kernel_zone;
+#endif /* CONFIG_NUMA */
+
+ return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE];
+kernel_zone:
+ return default_kernel_zone_for_pfn(nid, pfn, nr_pages);
+}
+
static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn,
unsigned long nr_pages)
{
return movable_node_enabled ? movable_zone : kernel_zone;
}
-struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,
+struct zone *zone_for_pfn_range(int online_type, int nid,
+ struct memory_group *group, unsigned long start_pfn,
unsigned long nr_pages)
{
if (online_type == MMOP_ONLINE_KERNEL)
if (online_type == MMOP_ONLINE_MOVABLE)
return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE];
+ if (online_policy == ONLINE_POLICY_AUTO_MOVABLE)
+ return auto_movable_zone_for_pfn(nid, group, start_pfn, nr_pages);
+
return default_zone_for_pfn(nid, start_pfn, nr_pages);
}
* This function should only be called by memory_block_{online,offline},
* and {online,offline}_pages.
*/
-void adjust_present_page_count(struct zone *zone, long nr_pages)
+void adjust_present_page_count(struct page *page, struct memory_group *group,
+ long nr_pages)
{
+ struct zone *zone = page_zone(page);
+ const bool movable = zone_idx(zone) == ZONE_MOVABLE;
+
+ /*
+ * We only support onlining/offlining/adding/removing of complete
+ * memory blocks; therefore, either all is either early or hotplugged.
+ */
+ if (early_section(__pfn_to_section(page_to_pfn(page))))
+ zone->present_early_pages += nr_pages;
zone->present_pages += nr_pages;
zone->zone_pgdat->node_present_pages += nr_pages;
+
+ if (group && movable)
+ group->present_movable_pages += nr_pages;
+ else if (group && !movable)
+ group->present_kernel_pages += nr_pages;
}
int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
kasan_remove_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages));
}
-int __ref online_pages(unsigned long pfn, unsigned long nr_pages, struct zone *zone)
+int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
+ struct zone *zone, struct memory_group *group)
{
unsigned long flags;
int need_zonelists_rebuild = 0;
}
online_pages_range(pfn, nr_pages);
- adjust_present_page_count(zone, nr_pages);
+ adjust_present_page_count(pfn_to_page(pfn), group, nr_pages);
node_states_set_node(nid, &arg);
if (need_zonelists_rebuild)
{
struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) };
struct vmem_altmap mhp_altmap = {};
+ struct memory_group *group = NULL;
u64 start, size;
bool new_node = false;
int ret;
if (ret)
return ret;
+ if (mhp_flags & MHP_NID_IS_MGID) {
+ group = memory_group_find_by_id(nid);
+ if (!group)
+ return -EINVAL;
+ nid = group->nid;
+ }
+
if (!node_possible(nid)) {
WARN(1, "node %d was absent from the node_possible_map\n", nid);
return -EINVAL;
goto error;
/* create memory block devices after memory was added */
- ret = create_memory_block_devices(start, size, mhp_altmap.alloc);
+ ret = create_memory_block_devices(start, size, mhp_altmap.alloc,
+ group);
if (ret) {
- arch_remove_memory(nid, start, size, NULL);
+ arch_remove_memory(start, size, NULL);
goto error;
}
unsigned long pfn, sec_end_pfn;
struct zone *zone = NULL;
struct page *page;
- int i;
+
for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1);
pfn < end_pfn;
pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) {
continue;
for (; pfn < sec_end_pfn && pfn < end_pfn;
pfn += MAX_ORDER_NR_PAGES) {
- i = 0;
- /* This is just a CONFIG_HOLES_IN_ZONE check.*/
- while ((i < MAX_ORDER_NR_PAGES) &&
- !pfn_valid_within(pfn + i))
- i++;
- if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn)
- continue;
/* Check if we got outside of the zone */
- if (zone && !zone_spans_pfn(zone, pfn + i))
+ if (zone && !zone_spans_pfn(zone, pfn))
return NULL;
- page = pfn_to_page(pfn + i);
+ page = pfn_to_page(pfn);
if (zone && page_zone(page) != zone)
return NULL;
zone = page_zone(page);
return 0;
}
-int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
+int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages,
+ struct memory_group *group)
{
const unsigned long end_pfn = start_pfn + nr_pages;
unsigned long pfn, system_ram_pages = 0;
/* removal success */
adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages);
- adjust_present_page_count(zone, -nr_pages);
+ adjust_present_page_count(pfn_to_page(start_pfn), group, -nr_pages);
/* reinitialise watermarks and update pcp limits */
init_per_zone_wmark_min();
static int check_memblock_offlined_cb(struct memory_block *mem, void *arg)
{
int ret = !is_memblock_offlined(mem);
+ int *nid = arg;
+ *nid = mem->nid;
if (unlikely(ret)) {
phys_addr_t beginpa, endpa;
}
EXPORT_SYMBOL(try_offline_node);
-static int __ref try_remove_memory(int nid, u64 start, u64 size)
+static int __ref try_remove_memory(u64 start, u64 size)
{
- int rc = 0;
struct vmem_altmap mhp_altmap = {};
struct vmem_altmap *altmap = NULL;
unsigned long nr_vmemmap_pages;
+ int rc = 0, nid = NUMA_NO_NODE;
BUG_ON(check_hotplug_memory_range(start, size));
* All memory blocks must be offlined before removing memory. Check
* whether all memory blocks in question are offline and return error
* if this is not the case.
+ *
+ * While at it, determine the nid. Note that if we'd have mixed nodes,
+ * we'd only try to offline the last determined one -- which is good
+ * enough for the cases we care about.
*/
- rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb);
+ rc = walk_memory_blocks(start, size, &nid, check_memblock_offlined_cb);
if (rc)
return rc;
mem_hotplug_begin();
- arch_remove_memory(nid, start, size, altmap);
+ arch_remove_memory(start, size, altmap);
if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
memblock_free(start, size);
release_mem_region_adjustable(start, size);
- try_offline_node(nid);
+ if (nid != NUMA_NO_NODE)
+ try_offline_node(nid);
mem_hotplug_done();
return 0;
/**
* __remove_memory - Remove memory if every memory block is offline
- * @nid: the node ID
* @start: physical address of the region to remove
* @size: size of the region to remove
*
* and online/offline operations before this call, as required by
* try_offline_node().
*/
-void __remove_memory(int nid, u64 start, u64 size)
+void __remove_memory(u64 start, u64 size)
{
/*
* trigger BUG() if some memory is not offlined prior to calling this
* function
*/
- if (try_remove_memory(nid, start, size))
+ if (try_remove_memory(start, size))
BUG();
}
* Remove memory if every memory block is offline, otherwise return -EBUSY is
* some memory is not offline
*/
-int remove_memory(int nid, u64 start, u64 size)
+int remove_memory(u64 start, u64 size)
{
int rc;
lock_device_hotplug();
- rc = try_remove_memory(nid, start, size);
+ rc = try_remove_memory(start, size);
unlock_device_hotplug();
return rc;
* unplugged all memory (so it's no longer in use) and want to offline + remove
* that memory.
*/
-int offline_and_remove_memory(int nid, u64 start, u64 size)
+int offline_and_remove_memory(u64 start, u64 size)
{
const unsigned long mb_count = size / memory_block_size_bytes();
uint8_t *online_types, *tmp;
* This cannot fail as it cannot get onlined in the meantime.
*/
if (!rc) {
- rc = try_remove_memory(nid, start, size);
+ rc = try_remove_memory(start, size);
if (rc)
pr_err("%s: Failed to remove memory: %d", __func__, rc);
}
projects / linux-2.6-microblaze.git / blobdiff