13f49584bSSeongJae Park // SPDX-License-Identifier: GPL-2.0 23f49584bSSeongJae Park /* 33f49584bSSeongJae Park * DAMON Primitives for Virtual Address Spaces 43f49584bSSeongJae Park * 53f49584bSSeongJae Park * Author: SeongJae Park <sjpark@amazon.de> 63f49584bSSeongJae Park */ 73f49584bSSeongJae Park 83f49584bSSeongJae Park #define pr_fmt(fmt) "damon-va: " fmt 93f49584bSSeongJae Park 106dea8addSSeongJae Park #include <asm-generic/mman-common.h> 113f49584bSSeongJae Park #include <linux/highmem.h> 1246c3a0acSSeongJae Park #include <linux/hugetlb.h> 1346c3a0acSSeongJae Park #include <linux/mmu_notifier.h> 143f49584bSSeongJae Park #include <linux/page_idle.h> 153f49584bSSeongJae Park #include <linux/pagewalk.h> 168581fd40SJakub Kicinski #include <linux/sched/mm.h> 1746c3a0acSSeongJae Park 18f7d911c3SSeongJae Park #include "ops-common.h" 193f49584bSSeongJae Park 2017ccae8bSSeongJae Park #ifdef CONFIG_DAMON_VADDR_KUNIT_TEST 2117ccae8bSSeongJae Park #undef DAMON_MIN_REGION 2217ccae8bSSeongJae Park #define DAMON_MIN_REGION 1 2317ccae8bSSeongJae Park #endif 2417ccae8bSSeongJae Park 253f49584bSSeongJae Park /* 261971bd63SSeongJae Park * 't->pid' should be the pointer to the relevant 'struct pid' having reference 273f49584bSSeongJae Park * count. Caller must put the returned task, unless it is NULL. 283f49584bSSeongJae Park */ 2988f86dcfSSeongJae Park static inline struct task_struct *damon_get_task_struct(struct damon_target *t) 3088f86dcfSSeongJae Park { 311971bd63SSeongJae Park return get_pid_task(t->pid, PIDTYPE_PID); 3288f86dcfSSeongJae Park } 333f49584bSSeongJae Park 343f49584bSSeongJae Park /* 353f49584bSSeongJae Park * Get the mm_struct of the given target 363f49584bSSeongJae Park * 373f49584bSSeongJae Park * Caller _must_ put the mm_struct after use, unless it is NULL. 383f49584bSSeongJae Park * 393f49584bSSeongJae Park * Returns the mm_struct of the target on success, NULL on failure 403f49584bSSeongJae Park */ 413f49584bSSeongJae Park static struct mm_struct *damon_get_mm(struct damon_target *t) 423f49584bSSeongJae Park { 433f49584bSSeongJae Park struct task_struct *task; 443f49584bSSeongJae Park struct mm_struct *mm; 453f49584bSSeongJae Park 463f49584bSSeongJae Park task = damon_get_task_struct(t); 473f49584bSSeongJae Park if (!task) 483f49584bSSeongJae Park return NULL; 493f49584bSSeongJae Park 503f49584bSSeongJae Park mm = get_task_mm(task); 513f49584bSSeongJae Park put_task_struct(task); 523f49584bSSeongJae Park return mm; 533f49584bSSeongJae Park } 543f49584bSSeongJae Park 553f49584bSSeongJae Park /* 563f49584bSSeongJae Park * Functions for the initial monitoring target regions construction 573f49584bSSeongJae Park */ 583f49584bSSeongJae Park 593f49584bSSeongJae Park /* 603f49584bSSeongJae Park * Size-evenly split a region into 'nr_pieces' small regions 613f49584bSSeongJae Park * 623f49584bSSeongJae Park * Returns 0 on success, or negative error code otherwise. 633f49584bSSeongJae Park */ 643f49584bSSeongJae Park static int damon_va_evenly_split_region(struct damon_target *t, 653f49584bSSeongJae Park struct damon_region *r, unsigned int nr_pieces) 663f49584bSSeongJae Park { 673f49584bSSeongJae Park unsigned long sz_orig, sz_piece, orig_end; 683f49584bSSeongJae Park struct damon_region *n = NULL, *next; 693f49584bSSeongJae Park unsigned long start; 703f49584bSSeongJae Park 713f49584bSSeongJae Park if (!r || !nr_pieces) 723f49584bSSeongJae Park return -EINVAL; 733f49584bSSeongJae Park 743f49584bSSeongJae Park orig_end = r->ar.end; 753f49584bSSeongJae Park sz_orig = r->ar.end - r->ar.start; 763f49584bSSeongJae Park sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, DAMON_MIN_REGION); 773f49584bSSeongJae Park 783f49584bSSeongJae Park if (!sz_piece) 793f49584bSSeongJae Park return -EINVAL; 803f49584bSSeongJae Park 813f49584bSSeongJae Park r->ar.end = r->ar.start + sz_piece; 823f49584bSSeongJae Park next = damon_next_region(r); 833f49584bSSeongJae Park for (start = r->ar.end; start + sz_piece <= orig_end; 843f49584bSSeongJae Park start += sz_piece) { 853f49584bSSeongJae Park n = damon_new_region(start, start + sz_piece); 863f49584bSSeongJae Park if (!n) 873f49584bSSeongJae Park return -ENOMEM; 883f49584bSSeongJae Park damon_insert_region(n, r, next, t); 893f49584bSSeongJae Park r = n; 903f49584bSSeongJae Park } 913f49584bSSeongJae Park /* complement last region for possible rounding error */ 923f49584bSSeongJae Park if (n) 933f49584bSSeongJae Park n->ar.end = orig_end; 943f49584bSSeongJae Park 953f49584bSSeongJae Park return 0; 963f49584bSSeongJae Park } 973f49584bSSeongJae Park 983f49584bSSeongJae Park static unsigned long sz_range(struct damon_addr_range *r) 993f49584bSSeongJae Park { 1003f49584bSSeongJae Park return r->end - r->start; 1013f49584bSSeongJae Park } 1023f49584bSSeongJae Park 1033f49584bSSeongJae Park /* 1043f49584bSSeongJae Park * Find three regions separated by two biggest unmapped regions 1053f49584bSSeongJae Park * 1063f49584bSSeongJae Park * vma the head vma of the target address space 1073f49584bSSeongJae Park * regions an array of three address ranges that results will be saved 1083f49584bSSeongJae Park * 1093f49584bSSeongJae Park * This function receives an address space and finds three regions in it which 1103f49584bSSeongJae Park * separated by the two biggest unmapped regions in the space. Please refer to 1113f49584bSSeongJae Park * below comments of '__damon_va_init_regions()' function to know why this is 1123f49584bSSeongJae Park * necessary. 1133f49584bSSeongJae Park * 1143f49584bSSeongJae Park * Returns 0 if success, or negative error code otherwise. 1153f49584bSSeongJae Park */ 1163f49584bSSeongJae Park static int __damon_va_three_regions(struct vm_area_struct *vma, 1173f49584bSSeongJae Park struct damon_addr_range regions[3]) 1183f49584bSSeongJae Park { 1193f49584bSSeongJae Park struct damon_addr_range gap = {0}, first_gap = {0}, second_gap = {0}; 1203f49584bSSeongJae Park struct vm_area_struct *last_vma = NULL; 1213f49584bSSeongJae Park unsigned long start = 0; 1223f49584bSSeongJae Park struct rb_root rbroot; 1233f49584bSSeongJae Park 1243f49584bSSeongJae Park /* Find two biggest gaps so that first_gap > second_gap > others */ 1253f49584bSSeongJae Park for (; vma; vma = vma->vm_next) { 1263f49584bSSeongJae Park if (!last_vma) { 1273f49584bSSeongJae Park start = vma->vm_start; 1283f49584bSSeongJae Park goto next; 1293f49584bSSeongJae Park } 1303f49584bSSeongJae Park 1313f49584bSSeongJae Park if (vma->rb_subtree_gap <= sz_range(&second_gap)) { 1323f49584bSSeongJae Park rbroot.rb_node = &vma->vm_rb; 1333f49584bSSeongJae Park vma = rb_entry(rb_last(&rbroot), 1343f49584bSSeongJae Park struct vm_area_struct, vm_rb); 1353f49584bSSeongJae Park goto next; 1363f49584bSSeongJae Park } 1373f49584bSSeongJae Park 1383f49584bSSeongJae Park gap.start = last_vma->vm_end; 1393f49584bSSeongJae Park gap.end = vma->vm_start; 1403f49584bSSeongJae Park if (sz_range(&gap) > sz_range(&second_gap)) { 1418bd0b9daSYihao Han swap(gap, second_gap); 1423f49584bSSeongJae Park if (sz_range(&second_gap) > sz_range(&first_gap)) 1438bd0b9daSYihao Han swap(second_gap, first_gap); 1443f49584bSSeongJae Park } 1453f49584bSSeongJae Park next: 1463f49584bSSeongJae Park last_vma = vma; 1473f49584bSSeongJae Park } 1483f49584bSSeongJae Park 1493f49584bSSeongJae Park if (!sz_range(&second_gap) || !sz_range(&first_gap)) 1503f49584bSSeongJae Park return -EINVAL; 1513f49584bSSeongJae Park 1523f49584bSSeongJae Park /* Sort the two biggest gaps by address */ 1533f49584bSSeongJae Park if (first_gap.start > second_gap.start) 1548bd0b9daSYihao Han swap(first_gap, second_gap); 1553f49584bSSeongJae Park 1563f49584bSSeongJae Park /* Store the result */ 1573f49584bSSeongJae Park regions[0].start = ALIGN(start, DAMON_MIN_REGION); 1583f49584bSSeongJae Park regions[0].end = ALIGN(first_gap.start, DAMON_MIN_REGION); 1593f49584bSSeongJae Park regions[1].start = ALIGN(first_gap.end, DAMON_MIN_REGION); 1603f49584bSSeongJae Park regions[1].end = ALIGN(second_gap.start, DAMON_MIN_REGION); 1613f49584bSSeongJae Park regions[2].start = ALIGN(second_gap.end, DAMON_MIN_REGION); 1623f49584bSSeongJae Park regions[2].end = ALIGN(last_vma->vm_end, DAMON_MIN_REGION); 1633f49584bSSeongJae Park 1643f49584bSSeongJae Park return 0; 1653f49584bSSeongJae Park } 1663f49584bSSeongJae Park 1673f49584bSSeongJae Park /* 1683f49584bSSeongJae Park * Get the three regions in the given target (task) 1693f49584bSSeongJae Park * 1703f49584bSSeongJae Park * Returns 0 on success, negative error code otherwise. 1713f49584bSSeongJae Park */ 1723f49584bSSeongJae Park static int damon_va_three_regions(struct damon_target *t, 1733f49584bSSeongJae Park struct damon_addr_range regions[3]) 1743f49584bSSeongJae Park { 1753f49584bSSeongJae Park struct mm_struct *mm; 1763f49584bSSeongJae Park int rc; 1773f49584bSSeongJae Park 1783f49584bSSeongJae Park mm = damon_get_mm(t); 1793f49584bSSeongJae Park if (!mm) 1803f49584bSSeongJae Park return -EINVAL; 1813f49584bSSeongJae Park 1823f49584bSSeongJae Park mmap_read_lock(mm); 1833f49584bSSeongJae Park rc = __damon_va_three_regions(mm->mmap, regions); 1843f49584bSSeongJae Park mmap_read_unlock(mm); 1853f49584bSSeongJae Park 1863f49584bSSeongJae Park mmput(mm); 1873f49584bSSeongJae Park return rc; 1883f49584bSSeongJae Park } 1893f49584bSSeongJae Park 1903f49584bSSeongJae Park /* 1913f49584bSSeongJae Park * Initialize the monitoring target regions for the given target (task) 1923f49584bSSeongJae Park * 1933f49584bSSeongJae Park * t the given target 1943f49584bSSeongJae Park * 1953f49584bSSeongJae Park * Because only a number of small portions of the entire address space 1963f49584bSSeongJae Park * is actually mapped to the memory and accessed, monitoring the unmapped 1973f49584bSSeongJae Park * regions is wasteful. That said, because we can deal with small noises, 1983f49584bSSeongJae Park * tracking every mapping is not strictly required but could even incur a high 1993f49584bSSeongJae Park * overhead if the mapping frequently changes or the number of mappings is 2003f49584bSSeongJae Park * high. The adaptive regions adjustment mechanism will further help to deal 2013f49584bSSeongJae Park * with the noise by simply identifying the unmapped areas as a region that 2023f49584bSSeongJae Park * has no access. Moreover, applying the real mappings that would have many 2033f49584bSSeongJae Park * unmapped areas inside will make the adaptive mechanism quite complex. That 2043f49584bSSeongJae Park * said, too huge unmapped areas inside the monitoring target should be removed 2053f49584bSSeongJae Park * to not take the time for the adaptive mechanism. 2063f49584bSSeongJae Park * 2073f49584bSSeongJae Park * For the reason, we convert the complex mappings to three distinct regions 2083f49584bSSeongJae Park * that cover every mapped area of the address space. Also the two gaps 2093f49584bSSeongJae Park * between the three regions are the two biggest unmapped areas in the given 2103f49584bSSeongJae Park * address space. In detail, this function first identifies the start and the 2113f49584bSSeongJae Park * end of the mappings and the two biggest unmapped areas of the address space. 2123f49584bSSeongJae Park * Then, it constructs the three regions as below: 2133f49584bSSeongJae Park * 2143f49584bSSeongJae Park * [mappings[0]->start, big_two_unmapped_areas[0]->start) 2153f49584bSSeongJae Park * [big_two_unmapped_areas[0]->end, big_two_unmapped_areas[1]->start) 2163f49584bSSeongJae Park * [big_two_unmapped_areas[1]->end, mappings[nr_mappings - 1]->end) 2173f49584bSSeongJae Park * 2183f49584bSSeongJae Park * As usual memory map of processes is as below, the gap between the heap and 2193f49584bSSeongJae Park * the uppermost mmap()-ed region, and the gap between the lowermost mmap()-ed 2203f49584bSSeongJae Park * region and the stack will be two biggest unmapped regions. Because these 2213f49584bSSeongJae Park * gaps are exceptionally huge areas in usual address space, excluding these 2223f49584bSSeongJae Park * two biggest unmapped regions will be sufficient to make a trade-off. 2233f49584bSSeongJae Park * 2243f49584bSSeongJae Park * <heap> 2253f49584bSSeongJae Park * <BIG UNMAPPED REGION 1> 2263f49584bSSeongJae Park * <uppermost mmap()-ed region> 2273f49584bSSeongJae Park * (other mmap()-ed regions and small unmapped regions) 2283f49584bSSeongJae Park * <lowermost mmap()-ed region> 2293f49584bSSeongJae Park * <BIG UNMAPPED REGION 2> 2303f49584bSSeongJae Park * <stack> 2313f49584bSSeongJae Park */ 2323f49584bSSeongJae Park static void __damon_va_init_regions(struct damon_ctx *ctx, 2333f49584bSSeongJae Park struct damon_target *t) 2343f49584bSSeongJae Park { 235962fe7a6SSeongJae Park struct damon_target *ti; 2363f49584bSSeongJae Park struct damon_region *r; 2373f49584bSSeongJae Park struct damon_addr_range regions[3]; 2383f49584bSSeongJae Park unsigned long sz = 0, nr_pieces; 239962fe7a6SSeongJae Park int i, tidx = 0; 2403f49584bSSeongJae Park 2413f49584bSSeongJae Park if (damon_va_three_regions(t, regions)) { 242962fe7a6SSeongJae Park damon_for_each_target(ti, ctx) { 243962fe7a6SSeongJae Park if (ti == t) 244962fe7a6SSeongJae Park break; 245962fe7a6SSeongJae Park tidx++; 246962fe7a6SSeongJae Park } 247962fe7a6SSeongJae Park pr_debug("Failed to get three regions of %dth target\n", tidx); 2483f49584bSSeongJae Park return; 2493f49584bSSeongJae Park } 2503f49584bSSeongJae Park 2513f49584bSSeongJae Park for (i = 0; i < 3; i++) 2523f49584bSSeongJae Park sz += regions[i].end - regions[i].start; 2533f49584bSSeongJae Park if (ctx->min_nr_regions) 2543f49584bSSeongJae Park sz /= ctx->min_nr_regions; 2553f49584bSSeongJae Park if (sz < DAMON_MIN_REGION) 2563f49584bSSeongJae Park sz = DAMON_MIN_REGION; 2573f49584bSSeongJae Park 2583f49584bSSeongJae Park /* Set the initial three regions of the target */ 2593f49584bSSeongJae Park for (i = 0; i < 3; i++) { 2603f49584bSSeongJae Park r = damon_new_region(regions[i].start, regions[i].end); 2613f49584bSSeongJae Park if (!r) { 2623f49584bSSeongJae Park pr_err("%d'th init region creation failed\n", i); 2633f49584bSSeongJae Park return; 2643f49584bSSeongJae Park } 2653f49584bSSeongJae Park damon_add_region(r, t); 2663f49584bSSeongJae Park 2673f49584bSSeongJae Park nr_pieces = (regions[i].end - regions[i].start) / sz; 2683f49584bSSeongJae Park damon_va_evenly_split_region(t, r, nr_pieces); 2693f49584bSSeongJae Park } 2703f49584bSSeongJae Park } 2713f49584bSSeongJae Park 2723f49584bSSeongJae Park /* Initialize '->regions_list' of every target (task) */ 273cdeed009SXin Hao static void damon_va_init(struct damon_ctx *ctx) 2743f49584bSSeongJae Park { 2753f49584bSSeongJae Park struct damon_target *t; 2763f49584bSSeongJae Park 2773f49584bSSeongJae Park damon_for_each_target(t, ctx) { 2783f49584bSSeongJae Park /* the user may set the target regions as they want */ 2793f49584bSSeongJae Park if (!damon_nr_regions(t)) 2803f49584bSSeongJae Park __damon_va_init_regions(ctx, t); 2813f49584bSSeongJae Park } 2823f49584bSSeongJae Park } 2833f49584bSSeongJae Park 2843f49584bSSeongJae Park /* 2853f49584bSSeongJae Park * Functions for the dynamic monitoring target regions update 2863f49584bSSeongJae Park */ 2873f49584bSSeongJae Park 2883f49584bSSeongJae Park /* 2893f49584bSSeongJae Park * Check whether a region is intersecting an address range 2903f49584bSSeongJae Park * 2913f49584bSSeongJae Park * Returns true if it is. 2923f49584bSSeongJae Park */ 293cdeed009SXin Hao static bool damon_intersect(struct damon_region *r, 294cdeed009SXin Hao struct damon_addr_range *re) 2953f49584bSSeongJae Park { 2963f49584bSSeongJae Park return !(r->ar.end <= re->start || re->end <= r->ar.start); 2973f49584bSSeongJae Park } 2983f49584bSSeongJae Park 2993f49584bSSeongJae Park /* 3003f49584bSSeongJae Park * Update damon regions for the three big regions of the given target 3013f49584bSSeongJae Park * 3023f49584bSSeongJae Park * t the given target 3033f49584bSSeongJae Park * bregions the three big regions of the target 3043f49584bSSeongJae Park */ 3053f49584bSSeongJae Park static void damon_va_apply_three_regions(struct damon_target *t, 3063f49584bSSeongJae Park struct damon_addr_range bregions[3]) 3073f49584bSSeongJae Park { 3083f49584bSSeongJae Park struct damon_region *r, *next; 309a460a360SXin Hao unsigned int i; 3103f49584bSSeongJae Park 3113f49584bSSeongJae Park /* Remove regions which are not in the three big regions now */ 3123f49584bSSeongJae Park damon_for_each_region_safe(r, next, t) { 3133f49584bSSeongJae Park for (i = 0; i < 3; i++) { 3143f49584bSSeongJae Park if (damon_intersect(r, &bregions[i])) 3153f49584bSSeongJae Park break; 3163f49584bSSeongJae Park } 3173f49584bSSeongJae Park if (i == 3) 3183f49584bSSeongJae Park damon_destroy_region(r, t); 3193f49584bSSeongJae Park } 3203f49584bSSeongJae Park 3213f49584bSSeongJae Park /* Adjust intersecting regions to fit with the three big regions */ 3223f49584bSSeongJae Park for (i = 0; i < 3; i++) { 3233f49584bSSeongJae Park struct damon_region *first = NULL, *last; 3243f49584bSSeongJae Park struct damon_region *newr; 3253f49584bSSeongJae Park struct damon_addr_range *br; 3263f49584bSSeongJae Park 3273f49584bSSeongJae Park br = &bregions[i]; 3283f49584bSSeongJae Park /* Get the first and last regions which intersects with br */ 3293f49584bSSeongJae Park damon_for_each_region(r, t) { 3303f49584bSSeongJae Park if (damon_intersect(r, br)) { 3313f49584bSSeongJae Park if (!first) 3323f49584bSSeongJae Park first = r; 3333f49584bSSeongJae Park last = r; 3343f49584bSSeongJae Park } 3353f49584bSSeongJae Park if (r->ar.start >= br->end) 3363f49584bSSeongJae Park break; 3373f49584bSSeongJae Park } 3383f49584bSSeongJae Park if (!first) { 3393f49584bSSeongJae Park /* no damon_region intersects with this big region */ 3403f49584bSSeongJae Park newr = damon_new_region( 3413f49584bSSeongJae Park ALIGN_DOWN(br->start, 3423f49584bSSeongJae Park DAMON_MIN_REGION), 3433f49584bSSeongJae Park ALIGN(br->end, DAMON_MIN_REGION)); 3443f49584bSSeongJae Park if (!newr) 3453f49584bSSeongJae Park continue; 3463f49584bSSeongJae Park damon_insert_region(newr, damon_prev_region(r), r, t); 3473f49584bSSeongJae Park } else { 3483f49584bSSeongJae Park first->ar.start = ALIGN_DOWN(br->start, 3493f49584bSSeongJae Park DAMON_MIN_REGION); 3503f49584bSSeongJae Park last->ar.end = ALIGN(br->end, DAMON_MIN_REGION); 3513f49584bSSeongJae Park } 3523f49584bSSeongJae Park } 3533f49584bSSeongJae Park } 3543f49584bSSeongJae Park 3553f49584bSSeongJae Park /* 3563f49584bSSeongJae Park * Update regions for current memory mappings 3573f49584bSSeongJae Park */ 358cdeed009SXin Hao static void damon_va_update(struct damon_ctx *ctx) 3593f49584bSSeongJae Park { 3603f49584bSSeongJae Park struct damon_addr_range three_regions[3]; 3613f49584bSSeongJae Park struct damon_target *t; 3623f49584bSSeongJae Park 3633f49584bSSeongJae Park damon_for_each_target(t, ctx) { 3643f49584bSSeongJae Park if (damon_va_three_regions(t, three_regions)) 3653f49584bSSeongJae Park continue; 3663f49584bSSeongJae Park damon_va_apply_three_regions(t, three_regions); 3673f49584bSSeongJae Park } 3683f49584bSSeongJae Park } 3693f49584bSSeongJae Park 3703f49584bSSeongJae Park static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr, 3713f49584bSSeongJae Park unsigned long next, struct mm_walk *walk) 3723f49584bSSeongJae Park { 3733f49584bSSeongJae Park pte_t *pte; 3743f49584bSSeongJae Park spinlock_t *ptl; 3753f49584bSSeongJae Park 3763f49584bSSeongJae Park if (pmd_huge(*pmd)) { 3773f49584bSSeongJae Park ptl = pmd_lock(walk->mm, pmd); 3783f49584bSSeongJae Park if (pmd_huge(*pmd)) { 3793f49584bSSeongJae Park damon_pmdp_mkold(pmd, walk->mm, addr); 3803f49584bSSeongJae Park spin_unlock(ptl); 3813f49584bSSeongJae Park return 0; 3823f49584bSSeongJae Park } 3833f49584bSSeongJae Park spin_unlock(ptl); 3843f49584bSSeongJae Park } 3853f49584bSSeongJae Park 3863f49584bSSeongJae Park if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) 3873f49584bSSeongJae Park return 0; 3883f49584bSSeongJae Park pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); 3893f49584bSSeongJae Park if (!pte_present(*pte)) 3903f49584bSSeongJae Park goto out; 3913f49584bSSeongJae Park damon_ptep_mkold(pte, walk->mm, addr); 3923f49584bSSeongJae Park out: 3933f49584bSSeongJae Park pte_unmap_unlock(pte, ptl); 3943f49584bSSeongJae Park return 0; 3953f49584bSSeongJae Park } 3963f49584bSSeongJae Park 39749f4203aSBaolin Wang #ifdef CONFIG_HUGETLB_PAGE 39849f4203aSBaolin Wang static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm, 39949f4203aSBaolin Wang struct vm_area_struct *vma, unsigned long addr) 40049f4203aSBaolin Wang { 40149f4203aSBaolin Wang bool referenced = false; 40249f4203aSBaolin Wang pte_t entry = huge_ptep_get(pte); 40349f4203aSBaolin Wang struct page *page = pte_page(entry); 40449f4203aSBaolin Wang 40549f4203aSBaolin Wang get_page(page); 40649f4203aSBaolin Wang 40749f4203aSBaolin Wang if (pte_young(entry)) { 40849f4203aSBaolin Wang referenced = true; 40949f4203aSBaolin Wang entry = pte_mkold(entry); 41049f4203aSBaolin Wang huge_ptep_set_access_flags(vma, addr, pte, entry, 41149f4203aSBaolin Wang vma->vm_flags & VM_WRITE); 41249f4203aSBaolin Wang } 41349f4203aSBaolin Wang 41449f4203aSBaolin Wang #ifdef CONFIG_MMU_NOTIFIER 41549f4203aSBaolin Wang if (mmu_notifier_clear_young(mm, addr, 41649f4203aSBaolin Wang addr + huge_page_size(hstate_vma(vma)))) 41749f4203aSBaolin Wang referenced = true; 41849f4203aSBaolin Wang #endif /* CONFIG_MMU_NOTIFIER */ 41949f4203aSBaolin Wang 42049f4203aSBaolin Wang if (referenced) 42149f4203aSBaolin Wang set_page_young(page); 42249f4203aSBaolin Wang 42349f4203aSBaolin Wang set_page_idle(page); 42449f4203aSBaolin Wang put_page(page); 42549f4203aSBaolin Wang } 42649f4203aSBaolin Wang 42749f4203aSBaolin Wang static int damon_mkold_hugetlb_entry(pte_t *pte, unsigned long hmask, 42849f4203aSBaolin Wang unsigned long addr, unsigned long end, 42949f4203aSBaolin Wang struct mm_walk *walk) 43049f4203aSBaolin Wang { 43149f4203aSBaolin Wang struct hstate *h = hstate_vma(walk->vma); 43249f4203aSBaolin Wang spinlock_t *ptl; 43349f4203aSBaolin Wang pte_t entry; 43449f4203aSBaolin Wang 43549f4203aSBaolin Wang ptl = huge_pte_lock(h, walk->mm, pte); 43649f4203aSBaolin Wang entry = huge_ptep_get(pte); 43749f4203aSBaolin Wang if (!pte_present(entry)) 43849f4203aSBaolin Wang goto out; 43949f4203aSBaolin Wang 44049f4203aSBaolin Wang damon_hugetlb_mkold(pte, walk->mm, walk->vma, addr); 44149f4203aSBaolin Wang 44249f4203aSBaolin Wang out: 44349f4203aSBaolin Wang spin_unlock(ptl); 44449f4203aSBaolin Wang return 0; 44549f4203aSBaolin Wang } 44649f4203aSBaolin Wang #else 44749f4203aSBaolin Wang #define damon_mkold_hugetlb_entry NULL 44849f4203aSBaolin Wang #endif /* CONFIG_HUGETLB_PAGE */ 44949f4203aSBaolin Wang 450199b50f4SRikard Falkeborn static const struct mm_walk_ops damon_mkold_ops = { 4513f49584bSSeongJae Park .pmd_entry = damon_mkold_pmd_entry, 45249f4203aSBaolin Wang .hugetlb_entry = damon_mkold_hugetlb_entry, 4533f49584bSSeongJae Park }; 4543f49584bSSeongJae Park 4553f49584bSSeongJae Park static void damon_va_mkold(struct mm_struct *mm, unsigned long addr) 4563f49584bSSeongJae Park { 4573f49584bSSeongJae Park mmap_read_lock(mm); 4583f49584bSSeongJae Park walk_page_range(mm, addr, addr + 1, &damon_mkold_ops, NULL); 4593f49584bSSeongJae Park mmap_read_unlock(mm); 4603f49584bSSeongJae Park } 4613f49584bSSeongJae Park 4623f49584bSSeongJae Park /* 4633f49584bSSeongJae Park * Functions for the access checking of the regions 4643f49584bSSeongJae Park */ 4653f49584bSSeongJae Park 466b627b774SXin Hao static void __damon_va_prepare_access_check(struct damon_ctx *ctx, 4673f49584bSSeongJae Park struct mm_struct *mm, struct damon_region *r) 4683f49584bSSeongJae Park { 4693f49584bSSeongJae Park r->sampling_addr = damon_rand(r->ar.start, r->ar.end); 4703f49584bSSeongJae Park 4713f49584bSSeongJae Park damon_va_mkold(mm, r->sampling_addr); 4723f49584bSSeongJae Park } 4733f49584bSSeongJae Park 474cdeed009SXin Hao static void damon_va_prepare_access_checks(struct damon_ctx *ctx) 4753f49584bSSeongJae Park { 4763f49584bSSeongJae Park struct damon_target *t; 4773f49584bSSeongJae Park struct mm_struct *mm; 4783f49584bSSeongJae Park struct damon_region *r; 4793f49584bSSeongJae Park 4803f49584bSSeongJae Park damon_for_each_target(t, ctx) { 4813f49584bSSeongJae Park mm = damon_get_mm(t); 4823f49584bSSeongJae Park if (!mm) 4833f49584bSSeongJae Park continue; 4843f49584bSSeongJae Park damon_for_each_region(r, t) 485b627b774SXin Hao __damon_va_prepare_access_check(ctx, mm, r); 4863f49584bSSeongJae Park mmput(mm); 4873f49584bSSeongJae Park } 4883f49584bSSeongJae Park } 4893f49584bSSeongJae Park 4903f49584bSSeongJae Park struct damon_young_walk_private { 4913f49584bSSeongJae Park unsigned long *page_sz; 4923f49584bSSeongJae Park bool young; 4933f49584bSSeongJae Park }; 4943f49584bSSeongJae Park 4953f49584bSSeongJae Park static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr, 4963f49584bSSeongJae Park unsigned long next, struct mm_walk *walk) 4973f49584bSSeongJae Park { 4983f49584bSSeongJae Park pte_t *pte; 4993f49584bSSeongJae Park spinlock_t *ptl; 5003f49584bSSeongJae Park struct page *page; 5013f49584bSSeongJae Park struct damon_young_walk_private *priv = walk->private; 5023f49584bSSeongJae Park 5033f49584bSSeongJae Park #ifdef CONFIG_TRANSPARENT_HUGEPAGE 5043f49584bSSeongJae Park if (pmd_huge(*pmd)) { 5053f49584bSSeongJae Park ptl = pmd_lock(walk->mm, pmd); 5063f49584bSSeongJae Park if (!pmd_huge(*pmd)) { 5073f49584bSSeongJae Park spin_unlock(ptl); 5083f49584bSSeongJae Park goto regular_page; 5093f49584bSSeongJae Park } 5103f49584bSSeongJae Park page = damon_get_page(pmd_pfn(*pmd)); 5113f49584bSSeongJae Park if (!page) 5123f49584bSSeongJae Park goto huge_out; 5133f49584bSSeongJae Park if (pmd_young(*pmd) || !page_is_idle(page) || 5143f49584bSSeongJae Park mmu_notifier_test_young(walk->mm, 5153f49584bSSeongJae Park addr)) { 5163f49584bSSeongJae Park *priv->page_sz = ((1UL) << HPAGE_PMD_SHIFT); 5173f49584bSSeongJae Park priv->young = true; 5183f49584bSSeongJae Park } 5193f49584bSSeongJae Park put_page(page); 5203f49584bSSeongJae Park huge_out: 5213f49584bSSeongJae Park spin_unlock(ptl); 5223f49584bSSeongJae Park return 0; 5233f49584bSSeongJae Park } 5243f49584bSSeongJae Park 5253f49584bSSeongJae Park regular_page: 5263f49584bSSeongJae Park #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 5273f49584bSSeongJae Park 5283f49584bSSeongJae Park if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) 5293f49584bSSeongJae Park return -EINVAL; 5303f49584bSSeongJae Park pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); 5313f49584bSSeongJae Park if (!pte_present(*pte)) 5323f49584bSSeongJae Park goto out; 5333f49584bSSeongJae Park page = damon_get_page(pte_pfn(*pte)); 5343f49584bSSeongJae Park if (!page) 5353f49584bSSeongJae Park goto out; 5363f49584bSSeongJae Park if (pte_young(*pte) || !page_is_idle(page) || 5373f49584bSSeongJae Park mmu_notifier_test_young(walk->mm, addr)) { 5383f49584bSSeongJae Park *priv->page_sz = PAGE_SIZE; 5393f49584bSSeongJae Park priv->young = true; 5403f49584bSSeongJae Park } 5413f49584bSSeongJae Park put_page(page); 5423f49584bSSeongJae Park out: 5433f49584bSSeongJae Park pte_unmap_unlock(pte, ptl); 5443f49584bSSeongJae Park return 0; 5453f49584bSSeongJae Park } 5463f49584bSSeongJae Park 54749f4203aSBaolin Wang #ifdef CONFIG_HUGETLB_PAGE 54849f4203aSBaolin Wang static int damon_young_hugetlb_entry(pte_t *pte, unsigned long hmask, 54949f4203aSBaolin Wang unsigned long addr, unsigned long end, 55049f4203aSBaolin Wang struct mm_walk *walk) 55149f4203aSBaolin Wang { 55249f4203aSBaolin Wang struct damon_young_walk_private *priv = walk->private; 55349f4203aSBaolin Wang struct hstate *h = hstate_vma(walk->vma); 55449f4203aSBaolin Wang struct page *page; 55549f4203aSBaolin Wang spinlock_t *ptl; 55649f4203aSBaolin Wang pte_t entry; 55749f4203aSBaolin Wang 55849f4203aSBaolin Wang ptl = huge_pte_lock(h, walk->mm, pte); 55949f4203aSBaolin Wang entry = huge_ptep_get(pte); 56049f4203aSBaolin Wang if (!pte_present(entry)) 56149f4203aSBaolin Wang goto out; 56249f4203aSBaolin Wang 56349f4203aSBaolin Wang page = pte_page(entry); 56449f4203aSBaolin Wang get_page(page); 56549f4203aSBaolin Wang 56649f4203aSBaolin Wang if (pte_young(entry) || !page_is_idle(page) || 56749f4203aSBaolin Wang mmu_notifier_test_young(walk->mm, addr)) { 56849f4203aSBaolin Wang *priv->page_sz = huge_page_size(h); 56949f4203aSBaolin Wang priv->young = true; 57049f4203aSBaolin Wang } 57149f4203aSBaolin Wang 57249f4203aSBaolin Wang put_page(page); 57349f4203aSBaolin Wang 57449f4203aSBaolin Wang out: 57549f4203aSBaolin Wang spin_unlock(ptl); 57649f4203aSBaolin Wang return 0; 57749f4203aSBaolin Wang } 57849f4203aSBaolin Wang #else 57949f4203aSBaolin Wang #define damon_young_hugetlb_entry NULL 58049f4203aSBaolin Wang #endif /* CONFIG_HUGETLB_PAGE */ 58149f4203aSBaolin Wang 582199b50f4SRikard Falkeborn static const struct mm_walk_ops damon_young_ops = { 5833f49584bSSeongJae Park .pmd_entry = damon_young_pmd_entry, 58449f4203aSBaolin Wang .hugetlb_entry = damon_young_hugetlb_entry, 5853f49584bSSeongJae Park }; 5863f49584bSSeongJae Park 5873f49584bSSeongJae Park static bool damon_va_young(struct mm_struct *mm, unsigned long addr, 5883f49584bSSeongJae Park unsigned long *page_sz) 5893f49584bSSeongJae Park { 5903f49584bSSeongJae Park struct damon_young_walk_private arg = { 5913f49584bSSeongJae Park .page_sz = page_sz, 5923f49584bSSeongJae Park .young = false, 5933f49584bSSeongJae Park }; 5943f49584bSSeongJae Park 5953f49584bSSeongJae Park mmap_read_lock(mm); 5963f49584bSSeongJae Park walk_page_range(mm, addr, addr + 1, &damon_young_ops, &arg); 5973f49584bSSeongJae Park mmap_read_unlock(mm); 5983f49584bSSeongJae Park return arg.young; 5993f49584bSSeongJae Park } 6003f49584bSSeongJae Park 6013f49584bSSeongJae Park /* 6023f49584bSSeongJae Park * Check whether the region was accessed after the last preparation 6033f49584bSSeongJae Park * 6043f49584bSSeongJae Park * mm 'mm_struct' for the given virtual address space 6053f49584bSSeongJae Park * r the region to be checked 6063f49584bSSeongJae Park */ 607b627b774SXin Hao static void __damon_va_check_access(struct damon_ctx *ctx, 6083f49584bSSeongJae Park struct mm_struct *mm, struct damon_region *r) 6093f49584bSSeongJae Park { 6103f49584bSSeongJae Park static struct mm_struct *last_mm; 6113f49584bSSeongJae Park static unsigned long last_addr; 6123f49584bSSeongJae Park static unsigned long last_page_sz = PAGE_SIZE; 6133f49584bSSeongJae Park static bool last_accessed; 6143f49584bSSeongJae Park 6153f49584bSSeongJae Park /* If the region is in the last checked page, reuse the result */ 6163f49584bSSeongJae Park if (mm == last_mm && (ALIGN_DOWN(last_addr, last_page_sz) == 6173f49584bSSeongJae Park ALIGN_DOWN(r->sampling_addr, last_page_sz))) { 6183f49584bSSeongJae Park if (last_accessed) 6193f49584bSSeongJae Park r->nr_accesses++; 6203f49584bSSeongJae Park return; 6213f49584bSSeongJae Park } 6223f49584bSSeongJae Park 6233f49584bSSeongJae Park last_accessed = damon_va_young(mm, r->sampling_addr, &last_page_sz); 6243f49584bSSeongJae Park if (last_accessed) 6253f49584bSSeongJae Park r->nr_accesses++; 6263f49584bSSeongJae Park 6273f49584bSSeongJae Park last_mm = mm; 6283f49584bSSeongJae Park last_addr = r->sampling_addr; 6293f49584bSSeongJae Park } 6303f49584bSSeongJae Park 631cdeed009SXin Hao static unsigned int damon_va_check_accesses(struct damon_ctx *ctx) 6323f49584bSSeongJae Park { 6333f49584bSSeongJae Park struct damon_target *t; 6343f49584bSSeongJae Park struct mm_struct *mm; 6353f49584bSSeongJae Park struct damon_region *r; 6363f49584bSSeongJae Park unsigned int max_nr_accesses = 0; 6373f49584bSSeongJae Park 6383f49584bSSeongJae Park damon_for_each_target(t, ctx) { 6393f49584bSSeongJae Park mm = damon_get_mm(t); 6403f49584bSSeongJae Park if (!mm) 6413f49584bSSeongJae Park continue; 6423f49584bSSeongJae Park damon_for_each_region(r, t) { 643b627b774SXin Hao __damon_va_check_access(ctx, mm, r); 6443f49584bSSeongJae Park max_nr_accesses = max(r->nr_accesses, max_nr_accesses); 6453f49584bSSeongJae Park } 6463f49584bSSeongJae Park mmput(mm); 6473f49584bSSeongJae Park } 6483f49584bSSeongJae Park 6493f49584bSSeongJae Park return max_nr_accesses; 6503f49584bSSeongJae Park } 6513f49584bSSeongJae Park 6523f49584bSSeongJae Park /* 6533f49584bSSeongJae Park * Functions for the target validity check and cleanup 6543f49584bSSeongJae Park */ 6553f49584bSSeongJae Park 65685104056SSeongJae Park static bool damon_va_target_valid(void *target) 6573f49584bSSeongJae Park { 6583f49584bSSeongJae Park struct damon_target *t = target; 6593f49584bSSeongJae Park struct task_struct *task; 6603f49584bSSeongJae Park 6613f49584bSSeongJae Park task = damon_get_task_struct(t); 6623f49584bSSeongJae Park if (task) { 6633f49584bSSeongJae Park put_task_struct(task); 6643f49584bSSeongJae Park return true; 6653f49584bSSeongJae Park } 6663f49584bSSeongJae Park 6673f49584bSSeongJae Park return false; 6683f49584bSSeongJae Park } 6693f49584bSSeongJae Park 6706dea8addSSeongJae Park #ifndef CONFIG_ADVISE_SYSCALLS 6710e92c2eeSSeongJae Park static unsigned long damos_madvise(struct damon_target *target, 6720e92c2eeSSeongJae Park struct damon_region *r, int behavior) 6736dea8addSSeongJae Park { 6740e92c2eeSSeongJae Park return 0; 6756dea8addSSeongJae Park } 6766dea8addSSeongJae Park #else 6770e92c2eeSSeongJae Park static unsigned long damos_madvise(struct damon_target *target, 6780e92c2eeSSeongJae Park struct damon_region *r, int behavior) 6796dea8addSSeongJae Park { 6806dea8addSSeongJae Park struct mm_struct *mm; 6810e92c2eeSSeongJae Park unsigned long start = PAGE_ALIGN(r->ar.start); 6820e92c2eeSSeongJae Park unsigned long len = PAGE_ALIGN(r->ar.end - r->ar.start); 6830e92c2eeSSeongJae Park unsigned long applied; 6846dea8addSSeongJae Park 6856dea8addSSeongJae Park mm = damon_get_mm(target); 6866dea8addSSeongJae Park if (!mm) 6870e92c2eeSSeongJae Park return 0; 6886dea8addSSeongJae Park 6890e92c2eeSSeongJae Park applied = do_madvise(mm, start, len, behavior) ? 0 : len; 6906dea8addSSeongJae Park mmput(mm); 6910e92c2eeSSeongJae Park 6920e92c2eeSSeongJae Park return applied; 6936dea8addSSeongJae Park } 6946dea8addSSeongJae Park #endif /* CONFIG_ADVISE_SYSCALLS */ 6956dea8addSSeongJae Park 6960e92c2eeSSeongJae Park static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx, 6970e92c2eeSSeongJae Park struct damon_target *t, struct damon_region *r, 6980e92c2eeSSeongJae Park struct damos *scheme) 6996dea8addSSeongJae Park { 7006dea8addSSeongJae Park int madv_action; 7016dea8addSSeongJae Park 7026dea8addSSeongJae Park switch (scheme->action) { 7036dea8addSSeongJae Park case DAMOS_WILLNEED: 7046dea8addSSeongJae Park madv_action = MADV_WILLNEED; 7056dea8addSSeongJae Park break; 7066dea8addSSeongJae Park case DAMOS_COLD: 7076dea8addSSeongJae Park madv_action = MADV_COLD; 7086dea8addSSeongJae Park break; 7096dea8addSSeongJae Park case DAMOS_PAGEOUT: 7106dea8addSSeongJae Park madv_action = MADV_PAGEOUT; 7116dea8addSSeongJae Park break; 7126dea8addSSeongJae Park case DAMOS_HUGEPAGE: 7136dea8addSSeongJae Park madv_action = MADV_HUGEPAGE; 7146dea8addSSeongJae Park break; 7156dea8addSSeongJae Park case DAMOS_NOHUGEPAGE: 7166dea8addSSeongJae Park madv_action = MADV_NOHUGEPAGE; 7176dea8addSSeongJae Park break; 7182f0b548cSSeongJae Park case DAMOS_STAT: 7192f0b548cSSeongJae Park return 0; 7206dea8addSSeongJae Park default: 7210e92c2eeSSeongJae Park return 0; 7226dea8addSSeongJae Park } 7236dea8addSSeongJae Park 7246dea8addSSeongJae Park return damos_madvise(t, r, madv_action); 7256dea8addSSeongJae Park } 7266dea8addSSeongJae Park 727cdeed009SXin Hao static int damon_va_scheme_score(struct damon_ctx *context, 728cdeed009SXin Hao struct damon_target *t, struct damon_region *r, 729cdeed009SXin Hao struct damos *scheme) 730198f0f4cSSeongJae Park { 731198f0f4cSSeongJae Park 732198f0f4cSSeongJae Park switch (scheme->action) { 733198f0f4cSSeongJae Park case DAMOS_PAGEOUT: 734198f0f4cSSeongJae Park return damon_pageout_score(context, r, scheme); 735198f0f4cSSeongJae Park default: 736198f0f4cSSeongJae Park break; 737198f0f4cSSeongJae Park } 738198f0f4cSSeongJae Park 739198f0f4cSSeongJae Park return DAMOS_MAX_SCORE; 740198f0f4cSSeongJae Park } 741198f0f4cSSeongJae Park 7427752925fSSeongJae Park static int __init damon_va_initcall(void) 7437752925fSSeongJae Park { 7447752925fSSeongJae Park struct damon_operations ops = { 7457752925fSSeongJae Park .id = DAMON_OPS_VADDR, 7467752925fSSeongJae Park .init = damon_va_init, 7477752925fSSeongJae Park .update = damon_va_update, 7487752925fSSeongJae Park .prepare_access_checks = damon_va_prepare_access_checks, 7497752925fSSeongJae Park .check_accesses = damon_va_check_accesses, 7507752925fSSeongJae Park .reset_aggregated = NULL, 7517752925fSSeongJae Park .target_valid = damon_va_target_valid, 7527752925fSSeongJae Park .cleanup = NULL, 7537752925fSSeongJae Park .apply_scheme = damon_va_apply_scheme, 7547752925fSSeongJae Park .get_scheme_score = damon_va_scheme_score, 7557752925fSSeongJae Park }; 756*de6d0154SSeongJae Park /* ops for fixed virtual address ranges */ 757*de6d0154SSeongJae Park struct damon_operations ops_fvaddr = ops; 758*de6d0154SSeongJae Park int err; 7597752925fSSeongJae Park 760*de6d0154SSeongJae Park /* Don't set the monitoring target regions for the entire mapping */ 761*de6d0154SSeongJae Park ops_fvaddr.id = DAMON_OPS_FVADDR; 762*de6d0154SSeongJae Park ops_fvaddr.init = NULL; 763*de6d0154SSeongJae Park ops_fvaddr.update = NULL; 764*de6d0154SSeongJae Park 765*de6d0154SSeongJae Park err = damon_register_ops(&ops); 766*de6d0154SSeongJae Park if (err) 767*de6d0154SSeongJae Park return err; 768*de6d0154SSeongJae Park return damon_register_ops(&ops_fvaddr); 7697752925fSSeongJae Park }; 7707752925fSSeongJae Park 7717752925fSSeongJae Park subsys_initcall(damon_va_initcall); 7727752925fSSeongJae Park 77317ccae8bSSeongJae Park #include "vaddr-test.h" 774