diff options
Diffstat (limited to 'mm/mempolicy.c')
| -rw-r--r-- | mm/mempolicy.c | 685 |
1 files changed, 502 insertions, 183 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index bb37cd1a51d8..3b1dfd08338b 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -109,10 +109,12 @@ #include <linux/mmu_notifier.h> #include <linux/printk.h> #include <linux/swapops.h> +#include <linux/gcd.h> #include <asm/tlbflush.h> #include <asm/tlb.h> #include <linux/uaccess.h> +#include <linux/memory.h> #include "internal.h" @@ -139,31 +141,138 @@ static struct mempolicy default_policy = { static struct mempolicy preferred_node_policy[MAX_NUMNODES]; /* - * iw_table is the sysfs-set interleave weight table, a value of 0 denotes - * system-default value should be used. A NULL iw_table also denotes that - * system-default values should be used. Until the system-default table - * is implemented, the system-default is always 1. - * - * iw_table is RCU protected + * weightiness balances the tradeoff between small weights (cycles through nodes + * faster, more fair/even distribution) and large weights (smaller errors + * between actual bandwidth ratios and weight ratios). 32 is a number that has + * been found to perform at a reasonable compromise between the two goals. + */ +static const int weightiness = 32; + +/* + * A null weighted_interleave_state is interpreted as having .mode="auto", + * and .iw_table is interpreted as an array of 1s with length nr_node_ids. + */ +struct weighted_interleave_state { + bool mode_auto; + u8 iw_table[]; +}; +static struct weighted_interleave_state __rcu *wi_state; +static unsigned int *node_bw_table; + +/* + * wi_state_lock protects both wi_state and node_bw_table. + * node_bw_table is only used by writers to update wi_state. */ -static u8 __rcu *iw_table; -static DEFINE_MUTEX(iw_table_lock); +static DEFINE_MUTEX(wi_state_lock); static u8 get_il_weight(int node) { - u8 *table; - u8 weight; + struct weighted_interleave_state *state; + u8 weight = 1; rcu_read_lock(); - table = rcu_dereference(iw_table); - /* if no iw_table, use system default */ - weight = table ? table[node] : 1; - /* if value in iw_table is 0, use system default */ - weight = weight ? weight : 1; + state = rcu_dereference(wi_state); + if (state) + weight = state->iw_table[node]; rcu_read_unlock(); return weight; } +/* + * Convert bandwidth values into weighted interleave weights. + * Call with wi_state_lock. + */ +static void reduce_interleave_weights(unsigned int *bw, u8 *new_iw) +{ + u64 sum_bw = 0; + unsigned int cast_sum_bw, scaling_factor = 1, iw_gcd = 0; + int nid; + + for_each_node_state(nid, N_MEMORY) + sum_bw += bw[nid]; + + /* Scale bandwidths to whole numbers in the range [1, weightiness] */ + for_each_node_state(nid, N_MEMORY) { + /* + * Try not to perform 64-bit division. + * If sum_bw < scaling_factor, then sum_bw < U32_MAX. + * If sum_bw > scaling_factor, then round the weight up to 1. + */ + scaling_factor = weightiness * bw[nid]; + if (bw[nid] && sum_bw < scaling_factor) { + cast_sum_bw = (unsigned int)sum_bw; + new_iw[nid] = scaling_factor / cast_sum_bw; + } else { + new_iw[nid] = 1; + } + if (!iw_gcd) + iw_gcd = new_iw[nid]; + iw_gcd = gcd(iw_gcd, new_iw[nid]); + } + + /* 1:2 is strictly better than 16:32. Reduce by the weights' GCD. */ + for_each_node_state(nid, N_MEMORY) + new_iw[nid] /= iw_gcd; +} + +int mempolicy_set_node_perf(unsigned int node, struct access_coordinate *coords) +{ + struct weighted_interleave_state *new_wi_state, *old_wi_state = NULL; + unsigned int *old_bw, *new_bw; + unsigned int bw_val; + int i; + + bw_val = min(coords->read_bandwidth, coords->write_bandwidth); + new_bw = kcalloc(nr_node_ids, sizeof(unsigned int), GFP_KERNEL); + if (!new_bw) + return -ENOMEM; + + new_wi_state = kmalloc(struct_size(new_wi_state, iw_table, nr_node_ids), + GFP_KERNEL); + if (!new_wi_state) { + kfree(new_bw); + return -ENOMEM; + } + new_wi_state->mode_auto = true; + for (i = 0; i < nr_node_ids; i++) + new_wi_state->iw_table[i] = 1; + + /* + * Update bandwidth info, even in manual mode. That way, when switching + * to auto mode in the future, iw_table can be overwritten using + * accurate bw data. + */ + mutex_lock(&wi_state_lock); + + old_bw = node_bw_table; + if (old_bw) + memcpy(new_bw, old_bw, nr_node_ids * sizeof(*old_bw)); + new_bw[node] = bw_val; + node_bw_table = new_bw; + + old_wi_state = rcu_dereference_protected(wi_state, + lockdep_is_held(&wi_state_lock)); + if (old_wi_state && !old_wi_state->mode_auto) { + /* Manual mode; skip reducing weights and updating wi_state */ + mutex_unlock(&wi_state_lock); + kfree(new_wi_state); + goto out; + } + + /* NULL wi_state assumes auto=true; reduce weights and update wi_state*/ + reduce_interleave_weights(new_bw, new_wi_state->iw_table); + rcu_assign_pointer(wi_state, new_wi_state); + + mutex_unlock(&wi_state_lock); + if (old_wi_state) { + synchronize_rcu(); + kfree(old_wi_state); + } +out: + kfree(old_bw); + return 0; +} + /** * numa_nearest_node - Find nearest node by state * @node: Node id to start the search @@ -196,6 +305,37 @@ int numa_nearest_node(int node, unsigned int state) } EXPORT_SYMBOL_GPL(numa_nearest_node); +/** + * nearest_node_nodemask - Find the node in @mask at the nearest distance + * from @node. + * + * @node: a valid node ID to start the search from. + * @mask: a pointer to a nodemask representing the allowed nodes. + * + * This function iterates over all nodes in @mask and calculates the + * distance from the starting @node, then it returns the node ID that is + * the closest to @node, or MAX_NUMNODES if no node is found. + * + * Note that @node must be a valid node ID usable with node_distance(), + * providing an invalid node ID (e.g., NUMA_NO_NODE) may result in crashes + * or unexpected behavior. + */ +int nearest_node_nodemask(int node, nodemask_t *mask) +{ + int dist, n, min_dist = INT_MAX, min_node = MAX_NUMNODES; + + for_each_node_mask(n, *mask) { + dist = node_distance(node, n); + if (dist < min_dist) { + min_dist = dist; + min_node = n; + } + } + + return min_node; +} +EXPORT_SYMBOL_GPL(nearest_node_nodemask); + struct mempolicy *get_task_policy(struct task_struct *p) { struct mempolicy *pol = p->mempolicy; @@ -535,6 +675,7 @@ static void queue_folios_pmd(pmd_t *pmd, struct mm_walk *walk) static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { + const fpb_t fpb_flags = FPB_IGNORE_DIRTY | FPB_IGNORE_SOFT_DIRTY; struct vm_area_struct *vma = walk->vma; struct folio *folio; struct queue_pages *qp = walk->private; @@ -542,6 +683,7 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr, pte_t *pte, *mapped_pte; pte_t ptent; spinlock_t *ptl; + int max_nr, nr; ptl = pmd_trans_huge_lock(pmd, vma); if (ptl) { @@ -555,7 +697,9 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr, walk->action = ACTION_AGAIN; return 0; } - for (; addr != end; pte++, addr += PAGE_SIZE) { + for (; addr != end; pte += nr, addr += nr * PAGE_SIZE) { + max_nr = (end - addr) >> PAGE_SHIFT; + nr = 1; ptent = ptep_get(pte); if (pte_none(ptent)) continue; @@ -567,6 +711,10 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr, folio = vm_normal_folio(vma, addr, ptent); if (!folio || folio_is_zone_device(folio)) continue; + if (folio_test_large(folio) && max_nr != 1) + nr = folio_pte_batch(folio, addr, pte, ptent, + max_nr, fpb_flags, + NULL, NULL, NULL); /* * vm_normal_folio() filters out zero pages, but there might * still be reserved folios to skip, perhaps in a VDSO. @@ -599,7 +747,7 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr, if (!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) || !vma_migratable(vma) || !migrate_folio_add(folio, qp->pagelist, flags)) { - qp->nr_failed++; + qp->nr_failed += nr; if (strictly_unmovable(flags)) break; } @@ -642,12 +790,12 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask, * Unless MPOL_MF_MOVE_ALL, we try to avoid migrating a shared folio. * Choosing not to migrate a shared folio is not counted as a failure. * - * See folio_likely_mapped_shared() on possible imprecision when we + * See folio_maybe_mapped_shared() on possible imprecision when we * cannot easily detect if a folio is shared. */ if ((flags & MPOL_MF_MOVE_ALL) || - (!folio_likely_mapped_shared(folio) && !hugetlb_pmd_shared(pte))) - if (!isolate_hugetlb(folio, qp->pagelist)) + (!folio_maybe_mapped_shared(folio) && !hugetlb_pmd_shared(pte))) + if (!folio_isolate_hugetlb(folio, qp->pagelist)) qp->nr_failed++; unlock: spin_unlock(ptl); @@ -1033,10 +1181,10 @@ static bool migrate_folio_add(struct folio *folio, struct list_head *foliolist, * Unless MPOL_MF_MOVE_ALL, we try to avoid migrating a shared folio. * Choosing not to migrate a shared folio is not counted as a failure. * - * See folio_likely_mapped_shared() on possible imprecision when we + * See folio_maybe_mapped_shared() on possible imprecision when we * cannot easily detect if a folio is shared. */ - if ((flags & MPOL_MF_MOVE_ALL) || !folio_likely_mapped_shared(folio)) { + if ((flags & MPOL_MF_MOVE_ALL) || !folio_maybe_mapped_shared(folio)) { if (folio_isolate_lru(folio)) { list_add_tail(&folio->lru, foliolist); node_stat_mod_folio(folio, @@ -1080,6 +1228,10 @@ static long migrate_to_node(struct mm_struct *mm, int source, int dest, mmap_read_lock(mm); vma = find_vma(mm, 0); + if (unlikely(!vma)) { + mmap_read_unlock(mm); + return 0; + } /* * This does not migrate the range, but isolates all pages that @@ -1979,26 +2131,28 @@ static unsigned int read_once_policy_nodemask(struct mempolicy *pol, static unsigned int weighted_interleave_nid(struct mempolicy *pol, pgoff_t ilx) { + struct weighted_interleave_state *state; nodemask_t nodemask; unsigned int target, nr_nodes; - u8 *table; + u8 *table = NULL; unsigned int weight_total = 0; u8 weight; - int nid; + int nid = 0; nr_nodes = read_once_policy_nodemask(pol, &nodemask); if (!nr_nodes) return numa_node_id(); rcu_read_lock(); - table = rcu_dereference(iw_table); + + state = rcu_dereference(wi_state); + /* Uninitialized wi_state means we should assume all weights are 1 */ + if (state) + table = state->iw_table; + /* calculate the total weight */ - for_each_node_mask(nid, nodemask) { - /* detect system default usage */ - weight = table ? table[nid] : 1; - weight = weight ? weight : 1; - weight_total += weight; - } + for_each_node_mask(nid, nodemask) + weight_total += table ? table[nid] : 1; /* Calculate the node offset based on totals */ target = ilx % weight_total; @@ -2006,7 +2160,6 @@ static unsigned int weighted_interleave_nid(struct mempolicy *pol, pgoff_t ilx) while (target) { /* detect system default usage */ weight = table ? table[nid] : 1; - weight = weight ? weight : 1; if (target < weight) break; target -= weight; @@ -2201,9 +2354,9 @@ static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order, */ preferred_gfp = gfp | __GFP_NOWARN; preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); - page = __alloc_pages_noprof(preferred_gfp, order, nid, nodemask); + page = __alloc_frozen_pages_noprof(preferred_gfp, order, nid, nodemask); if (!page) - page = __alloc_pages_noprof(gfp, order, nid, NULL); + page = __alloc_frozen_pages_noprof(gfp, order, nid, NULL); return page; } @@ -2218,7 +2371,7 @@ static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order, * * Return: The page on success or NULL if allocation fails. */ -struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order, +static struct page *alloc_pages_mpol(gfp_t gfp, unsigned int order, struct mempolicy *pol, pgoff_t ilx, int nid) { nodemask_t *nodemask; @@ -2249,8 +2402,9 @@ struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order, * First, try to allocate THP only on local node, but * don't reclaim unnecessarily, just compact. */ - page = __alloc_pages_node_noprof(nid, - gfp | __GFP_THISNODE | __GFP_NORETRY, order); + page = __alloc_frozen_pages_noprof( + gfp | __GFP_THISNODE | __GFP_NORETRY, order, + nid, NULL); if (page || !(gfp & __GFP_DIRECT_RECLAIM)) return page; /* @@ -2262,9 +2416,10 @@ struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order, } } - page = __alloc_pages_noprof(gfp, order, nid, nodemask); + page = __alloc_frozen_pages_noprof(gfp, order, nid, nodemask); - if (unlikely(pol->mode == MPOL_INTERLEAVE) && page) { + if (unlikely(pol->mode == MPOL_INTERLEAVE || + pol->mode == MPOL_WEIGHTED_INTERLEAVE) && page) { /* skip NUMA_INTERLEAVE_HIT update if numa stats is disabled */ if (static_branch_likely(&vm_numa_stat_key) && page_to_nid(page) == nid) { @@ -2280,8 +2435,13 @@ struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order, struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order, struct mempolicy *pol, pgoff_t ilx, int nid) { - return page_rmappable_folio(alloc_pages_mpol_noprof(gfp | __GFP_COMP, - order, pol, ilx, nid)); + struct page *page = alloc_pages_mpol(gfp | __GFP_COMP, order, pol, + ilx, nid); + if (!page) + return NULL; + + set_page_refcounted(page); + return page_rmappable_folio(page); } /** @@ -2295,7 +2455,7 @@ struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order, * NUMA policy. The caller must hold the mmap_lock of the mm_struct of the * VMA to prevent it from going away. Should be used for all allocations * for folios that will be mapped into user space, excepting hugetlbfs, and - * excepting where direct use of alloc_pages_mpol() is more appropriate. + * excepting where direct use of folio_alloc_mpol() is more appropriate. * * Return: The folio on success or NULL if allocation fails. */ @@ -2316,6 +2476,21 @@ struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order, struct vm_area_struct } EXPORT_SYMBOL(vma_alloc_folio_noprof); +struct page *alloc_frozen_pages_noprof(gfp_t gfp, unsigned order) +{ + struct mempolicy *pol = &default_policy; + + /* + * No reference counting needed for current->mempolicy + * nor system default_policy + */ + if (!in_interrupt() && !(gfp & __GFP_THISNODE)) + pol = get_task_policy(current); + + return alloc_pages_mpol(gfp, order, pol, NO_INTERLEAVE_INDEX, + numa_node_id()); +} + /** * alloc_pages - Allocate pages. * @gfp: GFP flags. @@ -2332,17 +2507,11 @@ EXPORT_SYMBOL(vma_alloc_folio_noprof); */ struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order) { - struct mempolicy *pol = &default_policy; - - /* - * No reference counting needed for current->mempolicy - * nor system default_policy - */ - if (!in_interrupt() && !(gfp & __GFP_THISNODE)) - pol = get_task_policy(current); + struct page *page = alloc_frozen_pages_noprof(gfp, order); - return alloc_pages_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX, - numa_node_id()); + if (page) + set_page_refcounted(page); + return page; } EXPORT_SYMBOL(alloc_pages_noprof); @@ -2352,7 +2521,7 @@ struct folio *folio_alloc_noprof(gfp_t gfp, unsigned int order) } EXPORT_SYMBOL(folio_alloc_noprof); -static unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp, +static unsigned long alloc_pages_bulk_interleave(gfp_t gfp, struct mempolicy *pol, unsigned long nr_pages, struct page **page_array) { @@ -2371,13 +2540,13 @@ static unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp, if (delta) { nr_allocated = alloc_pages_bulk_noprof(gfp, interleave_nodes(pol), NULL, - nr_pages_per_node + 1, NULL, + nr_pages_per_node + 1, page_array); delta--; } else { nr_allocated = alloc_pages_bulk_noprof(gfp, interleave_nodes(pol), NULL, - nr_pages_per_node, NULL, page_array); + nr_pages_per_node, page_array); } page_array += nr_allocated; @@ -2387,17 +2556,18 @@ static unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp, return total_allocated; } -static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, +static unsigned long alloc_pages_bulk_weighted_interleave(gfp_t gfp, struct mempolicy *pol, unsigned long nr_pages, struct page **page_array) { + struct weighted_interleave_state *state; struct task_struct *me = current; unsigned int cpuset_mems_cookie; unsigned long total_allocated = 0; unsigned long nr_allocated = 0; unsigned long rounds; unsigned long node_pages, delta; - u8 *table, *weights, weight; + u8 *weights, weight; unsigned int weight_total = 0; unsigned long rem_pages = nr_pages; nodemask_t nodes; @@ -2426,7 +2596,7 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, if (weight && node_isset(node, nodes)) { node_pages = min(rem_pages, weight); nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages, - NULL, page_array); + page_array); page_array += nr_allocated; total_allocated += nr_allocated; /* if that's all the pages, no need to interleave */ @@ -2447,17 +2617,19 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, return total_allocated; rcu_read_lock(); - table = rcu_dereference(iw_table); - if (table) - memcpy(weights, table, nr_node_ids); - rcu_read_unlock(); + state = rcu_dereference(wi_state); + if (state) { + memcpy(weights, state->iw_table, nr_node_ids * sizeof(u8)); + rcu_read_unlock(); + } else { + rcu_read_unlock(); + for (i = 0; i < nr_node_ids; i++) + weights[i] = 1; + } /* calculate total, detect system default usage */ - for_each_node_mask(node, nodes) { - if (!weights[node]) - weights[node] = 1; + for_each_node_mask(node, nodes) weight_total += weights[node]; - } /* * Calculate rounds/partial rounds to minimize __alloc_pages_bulk calls. @@ -2489,7 +2661,7 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, if (!node_pages) break; nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages, - NULL, page_array); + page_array); page_array += nr_allocated; total_allocated += nr_allocated; if (total_allocated == nr_pages) @@ -2502,7 +2674,7 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, return total_allocated; } -static unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid, +static unsigned long alloc_pages_bulk_preferred_many(gfp_t gfp, int nid, struct mempolicy *pol, unsigned long nr_pages, struct page **page_array) { @@ -2513,11 +2685,11 @@ static unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid, preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); nr_allocated = alloc_pages_bulk_noprof(preferred_gfp, nid, &pol->nodes, - nr_pages, NULL, page_array); + nr_pages, page_array); if (nr_allocated < nr_pages) nr_allocated += alloc_pages_bulk_noprof(gfp, numa_node_id(), NULL, - nr_pages - nr_allocated, NULL, + nr_pages - nr_allocated, page_array + nr_allocated); return nr_allocated; } @@ -2528,7 +2700,7 @@ static unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid, * It can accelerate memory allocation especially interleaving * allocate memory. */ -unsigned long alloc_pages_bulk_array_mempolicy_noprof(gfp_t gfp, +unsigned long alloc_pages_bulk_mempolicy_noprof(gfp_t gfp, unsigned long nr_pages, struct page **page_array) { struct mempolicy *pol = &default_policy; @@ -2539,21 +2711,21 @@ unsigned long alloc_pages_bulk_array_mempolicy_noprof(gfp_t gfp, pol = get_task_policy(current); if (pol->mode == MPOL_INTERLEAVE) - return alloc_pages_bulk_array_interleave(gfp, pol, + return alloc_pages_bulk_interleave(gfp, pol, nr_pages, page_array); if (pol->mode == MPOL_WEIGHTED_INTERLEAVE) - return alloc_pages_bulk_array_weighted_interleave( + return alloc_pages_bulk_weighted_interleave( gfp, pol, nr_pages, page_array); if (pol->mode == MPOL_PREFERRED_MANY) - return alloc_pages_bulk_array_preferred_many(gfp, + return alloc_pages_bulk_preferred_many(gfp, numa_node_id(), pol, nr_pages, page_array); nid = numa_node_id(); nodemask = policy_nodemask(gfp, pol, NO_INTERLEAVE_INDEX, &nid); return alloc_pages_bulk_noprof(gfp, nid, nodemask, - nr_pages, NULL, page_array); + nr_pages, page_array); } int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst) @@ -3368,6 +3540,14 @@ struct iw_node_attr { int nid; }; +struct sysfs_wi_group { + struct kobject wi_kobj; + struct mutex kobj_lock; + struct iw_node_attr *nattrs[]; +}; + +static struct sysfs_wi_group *wi_group; + static ssize_t node_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -3382,177 +3562,316 @@ static ssize_t node_show(struct kobject *kobj, struct kobj_attribute *attr, static ssize_t node_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { + struct weighted_interleave_state *new_wi_state, *old_wi_state = NULL; struct iw_node_attr *node_attr; - u8 *new; - u8 *old; u8 weight = 0; + int i; node_attr = container_of(attr, struct iw_node_attr, kobj_attr); - if (count == 0 || sysfs_streq(buf, "")) - weight = 0; - else if (kstrtou8(buf, 0, &weight)) + if (count == 0 || sysfs_streq(buf, "") || + kstrtou8(buf, 0, &weight) || weight == 0) return -EINVAL; - new = kzalloc(nr_node_ids, GFP_KERNEL); - if (!new) + new_wi_state = kzalloc(struct_size(new_wi_state, iw_table, nr_node_ids), + GFP_KERNEL); + if (!new_wi_state) return -ENOMEM; - mutex_lock(&iw_table_lock); - old = rcu_dereference_protected(iw_table, - lockdep_is_held(&iw_table_lock)); - if (old) - memcpy(new, old, nr_node_ids); - new[node_attr->nid] = weight; - rcu_assign_pointer(iw_table, new); - mutex_unlock(&iw_table_lock); - synchronize_rcu(); - kfree(old); + mutex_lock(&wi_state_lock); + old_wi_state = rcu_dereference_protected(wi_state, + lockdep_is_held(&wi_state_lock)); + if (old_wi_state) { + memcpy(new_wi_state->iw_table, old_wi_state->iw_table, + nr_node_ids * sizeof(u8)); + } else { + for (i = 0; i < nr_node_ids; i++) + new_wi_state->iw_table[i] = 1; + } + new_wi_state->iw_table[node_attr->nid] = weight; + new_wi_state->mode_auto = false; + + rcu_assign_pointer(wi_state, new_wi_state); + mutex_unlock(&wi_state_lock); + if (old_wi_state) { + synchronize_rcu(); + kfree(old_wi_state); + } return count; } -static struct iw_node_attr **node_attrs; - -static void sysfs_wi_node_release(struct iw_node_attr *node_attr, - struct kobject *parent) +static ssize_t weighted_interleave_auto_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) { - if (!node_attr) - return; - sysfs_remove_file(parent, &node_attr->kobj_attr.attr); - kfree(node_attr->kobj_attr.attr.name); - kfree(node_attr); + struct weighted_interleave_state *state; + bool wi_auto = true; + + rcu_read_lock(); + state = rcu_dereference(wi_state); + if (state) + wi_auto = state->mode_auto; + rcu_read_unlock(); + + return sysfs_emit(buf, "%s\n", str_true_false(wi_auto)); } -static void sysfs_wi_release(struct kobject *wi_kobj) +static ssize_t weighted_interleave_auto_store(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, size_t count) { + struct weighted_interleave_state *new_wi_state, *old_wi_state = NULL; + unsigned int *bw; + bool input; int i; + if (kstrtobool(buf, &input)) + return -EINVAL; + + new_wi_state = kzalloc(struct_size(new_wi_state, iw_table, nr_node_ids), + GFP_KERNEL); + if (!new_wi_state) + return -ENOMEM; for (i = 0; i < nr_node_ids; i++) - sysfs_wi_node_release(node_attrs[i], wi_kobj); - kobject_put(wi_kobj); + new_wi_state->iw_table[i] = 1; + + mutex_lock(&wi_state_lock); + if (!input) { + old_wi_state = rcu_dereference_protected(wi_state, + lockdep_is_held(&wi_state_lock)); + if (!old_wi_state) + goto update_wi_state; + if (input == old_wi_state->mode_auto) { + mutex_unlock(&wi_state_lock); + return count; + } + + memcpy(new_wi_state->iw_table, old_wi_state->iw_table, + nr_node_ids * sizeof(u8)); + goto update_wi_state; + } + + bw = node_bw_table; + if (!bw) { + mutex_unlock(&wi_state_lock); + kfree(new_wi_state); + return -ENODEV; + } + + new_wi_state->mode_auto = true; + reduce_interleave_weights(bw, new_wi_state->iw_table); + +update_wi_state: + rcu_assign_pointer(wi_state, new_wi_state); + mutex_unlock(&wi_state_lock); + if (old_wi_state) { + synchronize_rcu(); + kfree(old_wi_state); + } + return count; +} + +static void sysfs_wi_node_delete(int nid) +{ + struct iw_node_attr *attr; + + if (nid < 0 || nid >= nr_node_ids) + return; + + mutex_lock(&wi_group->kobj_lock); + attr = wi_group->nattrs[nid]; + if (!attr) { + mutex_unlock(&wi_group->kobj_lock); + return; + } + + wi_group->nattrs[nid] = NULL; + mutex_unlock(&wi_group->kobj_lock); + + sysfs_remove_file(&wi_group->wi_kobj, &attr->kobj_attr.attr); + kfree(attr->kobj_attr.attr.name); + kfree(attr); +} + +static void sysfs_wi_node_delete_all(void) +{ + int nid; + + for (nid = 0; nid < nr_node_ids; nid++) + sysfs_wi_node_delete(nid); +} + +static void wi_state_free(void) +{ + struct weighted_interleave_state *old_wi_state; + + mutex_lock(&wi_state_lock); + + old_wi_state = rcu_dereference_protected(wi_state, + lockdep_is_held(&wi_state_lock)); + if (!old_wi_state) { + mutex_unlock(&wi_state_lock); + return; + } + + rcu_assign_pointer(wi_state, NULL); + mutex_unlock(&wi_state_lock); + synchronize_rcu(); + kfree(old_wi_state); +} + +static struct kobj_attribute wi_auto_attr = + __ATTR(auto, 0664, weighted_interleave_auto_show, + weighted_interleave_auto_store); + +static void wi_cleanup(void) { + sysfs_remove_file(&wi_group->wi_kobj, &wi_auto_attr.attr); + sysfs_wi_node_delete_all(); + wi_state_free(); +} + +static void wi_kobj_release(struct kobject *wi_kobj) +{ + kfree(wi_group); } static const struct kobj_type wi_ktype = { .sysfs_ops = &kobj_sysfs_ops, - .release = sysfs_wi_release, + .release = wi_kobj_release, }; -static int add_weight_node(int nid, struct kobject *wi_kobj) +static int sysfs_wi_node_add(int nid) { - struct iw_node_attr *node_attr; + int ret; char *name; + struct iw_node_attr *new_attr; - node_attr = kzalloc(sizeof(*node_attr), GFP_KERNEL); - if (!node_attr) + if (nid < 0 || nid >= nr_node_ids) { + pr_err("invalid node id: %d\n", nid); + return -EINVAL; + } + + new_attr = kzalloc(sizeof(*new_attr), GFP_KERNEL); + if (!new_attr) return -ENOMEM; name = kasprintf(GFP_KERNEL, "node%d", nid); if (!name) { - kfree(node_attr); + kfree(new_attr); return -ENOMEM; } - sysfs_attr_init(&node_attr->kobj_attr.attr); - node_attr->kobj_attr.attr.name = name; - node_attr->kobj_attr.attr.mode = 0644; - node_attr->kobj_attr.show = node_show; - node_attr->kobj_attr.store = node_store; - node_attr->nid = nid; + sysfs_attr_init(&new_attr->kobj_attr.attr); + new_attr->kobj_attr.attr.name = name; + new_attr->kobj_attr.attr.mode = 0644; + new_attr->kobj_attr.show = node_show; + new_attr->kobj_attr.store = node_store; + new_attr->nid = nid; - if (sysfs_create_file(wi_kobj, &node_attr->kobj_attr.attr)) { - kfree(node_attr->kobj_attr.attr.name); - kfree(node_attr); - pr_err("failed to add attribute to weighted_interleave\n"); - return -ENOMEM; + mutex_lock(&wi_group->kobj_lock); + if (wi_group->nattrs[nid]) { + mutex_unlock(&wi_group->kobj_lock); + ret = -EEXIST; + goto out; } - node_attrs[nid] = node_attr; + ret = sysfs_create_file(&wi_group->wi_kobj, &new_attr->kobj_attr.attr); + if (ret) { + mutex_unlock(&wi_group->kobj_lock); + goto out; + } + wi_group->nattrs[nid] = new_attr; + mutex_unlock(&wi_group->kobj_lock); return 0; + +out: + kfree(new_attr->kobj_attr.attr.name); + kfree(new_attr); + return ret; } -static int add_weighted_interleave_group(struct kobject *root_kobj) +static int wi_node_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + int err; + struct memory_notify *arg = data; + int nid = arg->status_change_nid; + + if (nid < 0) + return NOTIFY_OK; + + switch (action) { + case MEM_ONLINE: + err = sysfs_wi_node_add(nid); + if (err) + pr_err("failed to add sysfs for node%d during hotplug: %d\n", + nid, err); + break; + case MEM_OFFLINE: + sysfs_wi_node_delete(nid); + break; + } + + return NOTIFY_OK; +} + +static int __init add_weighted_interleave_group(struct kobject *mempolicy_kobj) { - struct kobject *wi_kobj; int nid, err; - wi_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL); - if (!wi_kobj) + wi_group = kzalloc(struct_size(wi_group, nattrs, nr_node_ids), + GFP_KERNEL); + if (!wi_group) return -ENOMEM; + mutex_init(&wi_group->kobj_lock); - err = kobject_init_and_add(wi_kobj, &wi_ktype, root_kobj, + err = kobject_init_and_add(&wi_group->wi_kobj, &wi_ktype, mempolicy_kobj, "weighted_interleave"); - if (err) { - kfree(wi_kobj); - return err; - } + if (err) + goto err_put_kobj; - for_each_node_state(nid, N_POSSIBLE) { - err = add_weight_node(nid, wi_kobj); + err = sysfs_create_file(&wi_group->wi_kobj, &wi_auto_attr.attr); + if (err) + goto err_put_kobj; + + for_each_online_node(nid) { + if (!node_state(nid, N_MEMORY)) + continue; + + err = sysfs_wi_node_add(nid); if (err) { - pr_err("failed to add sysfs [node%d]\n", nid); - break; + pr_err("failed to add sysfs for node%d during init: %d\n", + nid, err); + goto err_cleanup_kobj; } } - if (err) - kobject_put(wi_kobj); - return 0; -} -static void mempolicy_kobj_release(struct kobject *kobj) -{ - u8 *old; + hotplug_memory_notifier(wi_node_notifier, DEFAULT_CALLBACK_PRI); + return 0; - mutex_lock(&iw_table_lock); - old = rcu_dereference_protected(iw_table, - lockdep_is_held(&iw_table_lock)); - rcu_assign_pointer(iw_table, NULL); - mutex_unlock(&iw_table_lock); - synchronize_rcu(); - kfree(old); - kfree(node_attrs); - kfree(kobj); +err_cleanup_kobj: + wi_cleanup(); + kobject_del(&wi_group->wi_kobj); +err_put_kobj: + kobject_put(&wi_group->wi_kobj); + return err; } -static const struct kobj_type mempolicy_ktype = { - .release = mempolicy_kobj_release -}; - static int __init mempolicy_sysfs_init(void) { int err; static struct kobject *mempolicy_kobj; - mempolicy_kobj = kzalloc(sizeof(*mempolicy_kobj), GFP_KERNEL); - if (!mempolicy_kobj) { - err = -ENOMEM; - goto err_out; - } - - node_attrs = kcalloc(nr_node_ids, sizeof(struct iw_node_attr *), - GFP_KERNEL); - if (!node_attrs) { - err = -ENOMEM; - goto mempol_out; - } + mempolicy_kobj = kobject_create_and_add("mempolicy", mm_kobj); + if (!mempolicy_kobj) + return -ENOMEM; - err = kobject_init_and_add(mempolicy_kobj, &mempolicy_ktype, mm_kobj, - "mempolicy"); + err = add_weighted_interleave_group(mempolicy_kobj); if (err) - goto node_out; + goto err_kobj; - err = add_weighted_interleave_group(mempolicy_kobj); - if (err) { - pr_err("mempolicy sysfs structure failed to initialize\n"); - kobject_put(mempolicy_kobj); - return err; - } + return 0; - return err; -node_out: - kfree(node_attrs); -mempol_out: - kfree(mempolicy_kobj); -err_out: - pr_err("failed to add mempolicy kobject to the system\n"); +err_kobj: + kobject_del(mempolicy_kobj); + kobject_put(mempolicy_kobj); return err; } |