cregit-Linux how code gets into the kernel

Release 4.11 mm/hugetlb_cgroup.c

Directory: mm
/*
 *
 * Copyright IBM Corporation, 2012
 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2.1 of the GNU Lesser General Public License
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 */

#include <linux/cgroup.h>
#include <linux/page_counter.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
#include <linux/hugetlb_cgroup.h>


struct hugetlb_cgroup {
	
struct cgroup_subsys_state css;
	/*
         * the counter to account for hugepages from hugetlb.
         */
	
struct page_counter hugepage[HUGE_MAX_HSTATE];
};


#define MEMFILE_PRIVATE(x, val)	(((x) << 16) | (val))

#define MEMFILE_IDX(val)	(((val) >> 16) & 0xffff)

#define MEMFILE_ATTR(val)	((val) & 0xffff)


static struct hugetlb_cgroup *root_h_cgroup __read_mostly;


static inline struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s) { return s ? container_of(s, struct hugetlb_cgroup, css) : NULL; }

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Aneesh Kumar K.V2586.21%150.00%
Tejun Heo413.79%150.00%
Total29100.00%2100.00%


static inline struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task) { return hugetlb_cgroup_from_css(task_css(task, hugetlb_cgrp_id)); }

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Aneesh Kumar K.V2392.00%133.33%
Tejun Heo28.00%266.67%
Total25100.00%3100.00%


static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg) { return (h_cg == root_h_cgroup); }

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Aneesh Kumar K.V19100.00%1100.00%
Total19100.00%1100.00%


static inline struct hugetlb_cgroup * parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg) { return hugetlb_cgroup_from_css(h_cg->css.parent); }

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Aneesh Kumar K.V1458.33%125.00%
Tejun Heo1041.67%375.00%
Total24100.00%4100.00%


static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg) { int idx; for (idx = 0; idx < hugetlb_max_hstate; idx++) { if (page_counter_read(&h_cg->hugepage[idx])) return true; } return false; }

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Aneesh Kumar K.V4693.88%133.33%
Tejun Heo24.08%133.33%
Johannes Weiner12.04%133.33%
Total49100.00%3100.00%


static void hugetlb_cgroup_init(struct hugetlb_cgroup *h_cgroup, struct hugetlb_cgroup *parent_h_cgroup) { int idx; for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) { struct page_counter *counter = &h_cgroup->hugepage[idx]; struct page_counter *parent = NULL; unsigned long limit; int ret; if (parent_h_cgroup) parent = &parent_h_cgroup->hugepage[idx]; page_counter_init(counter, parent); limit = round_down(PAGE_COUNTER_MAX, 1 << huge_page_order(&hstates[idx])); ret = page_counter_limit(counter, limit); VM_BUG_ON(ret); } }

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David Rientjes114100.00%1100.00%
Total114100.00%1100.00%


static struct cgroup_subsys_state * hugetlb_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) { struct hugetlb_cgroup *parent_h_cgroup = hugetlb_cgroup_from_css(parent_css); struct hugetlb_cgroup *h_cgroup; h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL); if (!h_cgroup) return ERR_PTR(-ENOMEM); if (!parent_h_cgroup) root_h_cgroup = h_cgroup; hugetlb_cgroup_init(h_cgroup, parent_h_cgroup); return &h_cgroup->css; }

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Aneesh Kumar K.V6080.00%125.00%
Tejun Heo1216.00%250.00%
David Rientjes34.00%125.00%
Total75100.00%4100.00%


static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css) { struct hugetlb_cgroup *h_cgroup; h_cgroup = hugetlb_cgroup_from_css(css); kfree(h_cgroup); }

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Aneesh Kumar K.V2382.14%133.33%
Tejun Heo517.86%266.67%
Total28100.00%3100.00%

/* * Should be called with hugetlb_lock held. * Since we are holding hugetlb_lock, pages cannot get moved from * active list or uncharged from the cgroup, So no need to get * page reference and test for page active here. This function * cannot fail. */
static void hugetlb_cgroup_move_parent(int idx, struct hugetlb_cgroup *h_cg, struct page *page) { unsigned int nr_pages; struct page_counter *counter; struct hugetlb_cgroup *page_hcg; struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(h_cg); page_hcg = hugetlb_cgroup_from_page(page); /* * We can have pages in active list without any cgroup * ie, hugepage with less than 3 pages. We can safely * ignore those pages. */ if (!page_hcg || page_hcg != h_cg) goto out; nr_pages = 1 << compound_order(page); if (!parent) { parent = root_h_cgroup; /* root has no limit */ page_counter_charge(&parent->hugepage[idx], nr_pages); } counter = &h_cg->hugepage[idx]; /* Take the pages off the local counter */ page_counter_cancel(counter, nr_pages); set_hugetlb_cgroup(page, parent); out: return; }

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Aneesh Kumar K.V11289.60%133.33%
Johannes Weiner108.00%133.33%
Tejun Heo32.40%133.33%
Total125100.00%3100.00%

/* * Force the hugetlb cgroup to empty the hugetlb resources by moving them to * the parent cgroup. */
static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css) { struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); struct hstate *h; struct page *page; int idx = 0; do { for_each_hstate(h) { spin_lock(&hugetlb_lock); list_for_each_entry(page, &h->hugepage_activelist, lru) hugetlb_cgroup_move_parent(idx, h_cg, page); spin_unlock(&hugetlb_lock); idx++; } cond_resched(); } while (hugetlb_cgroup_have_usage(h_cg)); }

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Aneesh Kumar K.V7281.82%233.33%
Tejun Heo1618.18%466.67%
Total88100.00%6100.00%


int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup **ptr) { int ret = 0; struct page_counter *counter; struct hugetlb_cgroup *h_cg = NULL; if (hugetlb_cgroup_disabled()) goto done; /* * We don't charge any cgroup if the compound page have less * than 3 pages. */ if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER) goto done; again: rcu_read_lock(); h_cg = hugetlb_cgroup_from_task(current); if (!css_tryget_online(&h_cg->css)) { rcu_read_unlock(); goto again; } rcu_read_unlock(); if (!page_counter_try_charge(&h_cg->hugepage[idx], nr_pages, &counter)) ret = -ENOMEM; css_put(&h_cg->css); done: *ptr = h_cg; return ret; }

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Aneesh Kumar K.V12289.71%125.00%
Johannes Weiner139.56%250.00%
Tejun Heo10.74%125.00%
Total136100.00%4100.00%

/* Should be called with hugetlb_lock held */
void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg, struct page *page) { if (hugetlb_cgroup_disabled() || !h_cg) return; set_hugetlb_cgroup(page, h_cg); return; }

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Aneesh Kumar K.V39100.00%1100.00%
Total39100.00%1100.00%

/* * Should be called with hugetlb_lock held */
void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, struct page *page) { struct hugetlb_cgroup *h_cg; if (hugetlb_cgroup_disabled()) return; lockdep_assert_held(&hugetlb_lock); h_cg = hugetlb_cgroup_from_page(page); if (unlikely(!h_cg)) return; set_hugetlb_cgroup(page, NULL); page_counter_uncharge(&h_cg->hugepage[idx], nr_pages); return; }

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Aneesh Kumar K.V6895.77%133.33%
Johannes Weiner22.82%133.33%
Michal Hocko11.41%133.33%
Total71100.00%3100.00%


void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg) { if (hugetlb_cgroup_disabled() || !h_cg) return; if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER) return; page_counter_uncharge(&h_cg->hugepage[idx], nr_pages); return; }

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Aneesh Kumar K.V5296.30%150.00%
Johannes Weiner23.70%150.00%
Total54100.00%2100.00%

enum { RES_USAGE, RES_LIMIT, RES_MAX_USAGE, RES_FAILCNT, };
static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css, struct cftype *cft) { struct page_counter *counter; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)]; switch (MEMFILE_ATTR(cft->private)) { case RES_USAGE: return (u64)page_counter_read(counter) * PAGE_SIZE; case RES_LIMIT: return (u64)counter->limit * PAGE_SIZE; case RES_MAX_USAGE: return (u64)counter->watermark * PAGE_SIZE; case RES_FAILCNT: return counter->failcnt; default: BUG(); } }

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PersonTokensPropCommitsCommitProp
Johannes Weiner6458.72%125.00%
Aneesh Kumar K.V3834.86%125.00%
Tejun Heo76.42%250.00%
Total109100.00%4100.00%

static DEFINE_MUTEX(hugetlb_limit_mutex);
static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { int ret, idx; unsigned long nr_pages; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */ return -EINVAL; buf = strstrip(buf); ret = page_counter_memparse(buf, "-1", &nr_pages); if (ret) return ret; idx = MEMFILE_IDX(of_cft(of)->private); nr_pages = round_down(nr_pages, 1 << huge_page_order(&hstates[idx])); switch (MEMFILE_ATTR(of_cft(of)->private)) { case RES_LIMIT: mutex_lock(&hugetlb_limit_mutex); ret = page_counter_limit(&h_cg->hugepage[idx], nr_pages); mutex_unlock(&hugetlb_limit_mutex); break; default: ret = -EINVAL; break; } return ret ?: nbytes; }

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PersonTokensPropCommitsCommitProp
Aneesh Kumar K.V6840.24%114.29%
Johannes Weiner4627.22%228.57%
Tejun Heo3319.53%228.57%
David Rientjes2213.02%228.57%
Total169100.00%7100.00%


static ssize_t hugetlb_cgroup_reset(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { int ret = 0; struct page_counter *counter; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)]; switch (MEMFILE_ATTR(of_cft(of)->private)) { case RES_MAX_USAGE: page_counter_reset_watermark(counter); break; case RES_FAILCNT: counter->failcnt = 0; break; default: ret = -EINVAL; break; } return ret ?: nbytes; }

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PersonTokensPropCommitsCommitProp
Aneesh Kumar K.V5651.85%125.00%
Tejun Heo3229.63%250.00%
Johannes Weiner2018.52%125.00%
Total108100.00%4100.00%


static char *mem_fmt(char *buf, int size, unsigned long hsize) { if (hsize >= (1UL << 30)) snprintf(buf, size, "%luGB", hsize >> 30); else if (hsize >= (1UL << 20)) snprintf(buf, size, "%luMB", hsize >> 20); else snprintf(buf, size, "%luKB", hsize >> 10); return buf; }

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Aneesh Kumar K.V82100.00%1100.00%
Total82100.00%1100.00%


static void __init __hugetlb_cgroup_file_init(int idx) { char buf[32]; struct cftype *cft; struct hstate *h = &hstates[idx]; /* format the size */ mem_fmt(buf, 32, huge_page_size(h)); /* Add the limit file */ cft = &h->cgroup_files[0]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT); cft->read_u64 = hugetlb_cgroup_read_u64; cft->write = hugetlb_cgroup_write; /* Add the usage file */ cft = &h->cgroup_files[1]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_USAGE); cft->read_u64 = hugetlb_cgroup_read_u64; /* Add the MAX usage file */ cft = &h->cgroup_files[2]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE); cft->write = hugetlb_cgroup_reset; cft->read_u64 = hugetlb_cgroup_read_u64; /* Add the failcntfile */ cft = &h->cgroup_files[3]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf); cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT); cft->write = hugetlb_cgroup_reset; cft->read_u64 = hugetlb_cgroup_read_u64; /* NULL terminate the last cft */ cft = &h->cgroup_files[4]; memset(cft, 0, sizeof(*cft)); WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys, h->cgroup_files)); }

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Aneesh Kumar K.V24793.56%114.29%
Tejun Heo134.92%571.43%
Jianguo Wu41.52%114.29%
Total264100.00%7100.00%


void __init hugetlb_cgroup_file_init(void) { struct hstate *h; for_each_hstate(h) { /* * Add cgroup control files only if the huge page consists * of more than two normal pages. This is because we use * page[2].private for storing cgroup details. */ if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER) __hugetlb_cgroup_file_init(hstate_index(h)); } }

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Jianguo Wu3594.59%133.33%
Aneesh Kumar K.V12.70%133.33%
Kirill A. Shutemov12.70%133.33%
Total37100.00%3100.00%

/* * hugetlb_lock will make sure a parallel cgroup rmdir won't happen * when we migrate hugepages */
void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage) { struct hugetlb_cgroup *h_cg; struct hstate *h = page_hstate(oldhpage); if (hugetlb_cgroup_disabled()) return; VM_BUG_ON_PAGE(!PageHuge(oldhpage), oldhpage); spin_lock(&hugetlb_lock); h_cg = hugetlb_cgroup_from_page(oldhpage); set_hugetlb_cgroup(oldhpage, NULL); /* move the h_cg details to new cgroup */ set_hugetlb_cgroup(newhpage, h_cg); list_move(&newhpage->lru, &h->hugepage_activelist); spin_unlock(&hugetlb_lock); return; }

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Aneesh Kumar K.V9296.84%266.67%
Sasha Levin33.16%133.33%
Total95100.00%3100.00%

struct cgroup_subsys hugetlb_cgrp_subsys = { .css_alloc = hugetlb_cgroup_css_alloc, .css_offline = hugetlb_cgroup_css_offline, .css_free = hugetlb_cgroup_css_free, };

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PersonTokensPropCommitsCommitProp
Aneesh Kumar K.V133772.43%722.58%
Johannes Weiner1799.70%39.68%
Tejun Heo1477.96%1548.39%
David Rientjes1397.53%26.45%
Jianguo Wu392.11%13.23%
Sasha Levin30.16%13.23%
Kirill A. Shutemov10.05%13.23%
Michal Hocko10.05%13.23%
Total1846100.00%31100.00%
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