// SPDX-License-Identifier: GPL-2.0 /* * proactive reclamation: monitor access pattern of a given process, find * regions that seems not accessed, and proactively page out the regions. */ #define pr_fmt(fmt) "damon_sample_prcl: " fmt #include <linux/damon.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> static int target_pid __read_mostly; module_param(target_pid, int, 0600); static int damon_sample_prcl_enable_store( const char *val, const struct kernel_param *kp); static const struct kernel_param_ops enable_param_ops = { .set = damon_sample_prcl_enable_store, .get = param_get_bool, }; static bool enable __read_mostly; module_param_cb(enable, &enable_param_ops, &enable, 0600); MODULE_PARM_DESC(enable, "Enable of disable DAMON_SAMPLE_WSSE"); static struct damon_ctx *ctx; static struct pid *target_pidp; static int damon_sample_prcl_after_aggregate(struct damon_ctx *c) { struct damon_target *t; damon_for_each_target(t, c) { struct damon_region *r; unsigned long wss = 0; damon_for_each_region(r, t) { if (r->nr_accesses > 0) wss += r->ar.end - r->ar.start; } pr_info("wss: %lu\n", wss); } return 0; } static int damon_sample_prcl_start(void) { struct damon_target *target; struct damos *scheme; pr_info("start\n"); ctx = damon_new_ctx(); if (!ctx) return -ENOMEM; if (damon_select_ops(ctx, DAMON_OPS_VADDR)) { damon_destroy_ctx(ctx); return -EINVAL; } target = damon_new_target(); if (!target) { damon_destroy_ctx(ctx); return -ENOMEM; } damon_add_target(ctx, target); target_pidp = find_get_pid(target_pid); if (!target_pidp) { damon_destroy_ctx(ctx); return -EINVAL; } target->pid = target_pidp; ctx->callback.after_aggregation = damon_sample_prcl_after_aggregate; scheme = damon_new_scheme( &(struct damos_access_pattern) { .min_sz_region = PAGE_SIZE, .max_sz_region = ULONG_MAX, .min_nr_accesses = 0, .max_nr_accesses = 0, .min_age_region = 50, .max_age_region = UINT_MAX}, DAMOS_PAGEOUT, 0, &(struct damos_quota){}, &(struct damos_watermarks){}, NUMA_NO_NODE); if (!scheme) { damon_destroy_ctx(ctx); return -ENOMEM; } damon_set_schemes(ctx, &scheme, 1); return damon_start(&ctx, 1, true); } static void damon_sample_prcl_stop(void) { pr_info("stop\n"); if (ctx) { damon_stop(&ctx, 1); damon_destroy_ctx(ctx); } if (target_pidp) put_pid(target_pidp); } static int damon_sample_prcl_enable_store( const char *val, const struct kernel_param *kp) { bool enabled = enable; int err; err = kstrtobool(val, &enable); if (err) return err; if (enable == enabled) return 0; if (enable) { err = damon_sample_prcl_start(); if (err) enable = false; return err; } damon_sample_prcl_stop(); return 0; } static int __init damon_sample_prcl_init(void) { return 0; } module_init(damon_sample_prcl_init);