From f47761999052b1cc987dd3e3d3adf47997358fc0 Mon Sep 17 00:00:00 2001 From: Mina Almasry Date: Fri, 14 Jan 2022 14:07:48 -0800 Subject: [PATCH] hugetlb: add hugetlb.*.numa_stat file For hugetlb backed jobs/VMs it's critical to understand the numa information for the memory backing these jobs to deliver optimal performance. Currently this technically can be queried from /proc/self/numa_maps, but there are significant issues with that. Namely: 1. Memory can be mapped or unmapped. 2. numa_maps are per process and need to be aggregated across all processes in the cgroup. For shared memory this is more involved as the userspace needs to make sure it doesn't double count shared mappings. 3. I believe querying numa_maps needs to hold the mmap_lock which adds to the contention on this lock. For these reasons I propose simply adding hugetlb.*.numa_stat file, which shows the numa information of the cgroup similarly to memory.numa_stat. On cgroup-v2: cat /sys/fs/cgroup/unified/test/hugetlb.2MB.numa_stat total=2097152 N0=2097152 N1=0 On cgroup-v1: cat /sys/fs/cgroup/hugetlb/test/hugetlb.2MB.numa_stat total=2097152 N0=2097152 N1=0 hierarichal_total=2097152 N0=2097152 N1=0 This patch was tested manually by allocating hugetlb memory and querying the hugetlb.*.numa_stat file of the cgroup and its parents. [colin.i.king@googlemail.com: fix spelling mistake "hierarichal" -> "hierarchical"] Link: https://lkml.kernel.org/r/20211125090635.23508-1-colin.i.king@gmail.com [keescook@chromium.org: fix copy/paste array assignment] Link: https://lkml.kernel.org/r/20211203065647.2819707-1-keescook@chromium.org Link: https://lkml.kernel.org/r/20211123001020.4083653-1-almasrymina@google.com Signed-off-by: Mina Almasry Signed-off-by: Colin Ian King Signed-off-by: Kees Cook Reviewed-by: Shakeel Butt Reviewed-by: Muchun Song Reviewed-by: Mike Kravetz Cc: Shuah Khan Cc: Miaohe Lin Cc: Oscar Salvador Cc: Michal Hocko Cc: David Rientjes Cc: Jue Wang Cc: Yang Yao Cc: Joanna Li Cc: Cannon Matthews Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- .../admin-guide/cgroup-v1/hugetlb.rst | 4 + Documentation/admin-guide/cgroup-v2.rst | 5 + include/linux/hugetlb.h | 4 +- include/linux/hugetlb_cgroup.h | 7 + mm/hugetlb_cgroup.c | 133 ++++++++++++++++-- 5 files changed, 141 insertions(+), 12 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v1/hugetlb.rst b/Documentation/admin-guide/cgroup-v1/hugetlb.rst index 338f2c7d7a1c..0fa724d82abb 100644 --- a/Documentation/admin-guide/cgroup-v1/hugetlb.rst +++ b/Documentation/admin-guide/cgroup-v1/hugetlb.rst @@ -29,12 +29,14 @@ Brief summary of control files:: hugetlb..max_usage_in_bytes # show max "hugepagesize" hugetlb usage recorded hugetlb..usage_in_bytes # show current usage for "hugepagesize" hugetlb hugetlb..failcnt # show the number of allocation failure due to HugeTLB usage limit + hugetlb..numa_stat # show the numa information of the hugetlb memory charged to this cgroup For a system supporting three hugepage sizes (64k, 32M and 1G), the control files include:: hugetlb.1GB.limit_in_bytes hugetlb.1GB.max_usage_in_bytes + hugetlb.1GB.numa_stat hugetlb.1GB.usage_in_bytes hugetlb.1GB.failcnt hugetlb.1GB.rsvd.limit_in_bytes @@ -43,6 +45,7 @@ files include:: hugetlb.1GB.rsvd.failcnt hugetlb.64KB.limit_in_bytes hugetlb.64KB.max_usage_in_bytes + hugetlb.64KB.numa_stat hugetlb.64KB.usage_in_bytes hugetlb.64KB.failcnt hugetlb.64KB.rsvd.limit_in_bytes @@ -51,6 +54,7 @@ files include:: hugetlb.64KB.rsvd.failcnt hugetlb.32MB.limit_in_bytes hugetlb.32MB.max_usage_in_bytes + hugetlb.32MB.numa_stat hugetlb.32MB.usage_in_bytes hugetlb.32MB.failcnt hugetlb.32MB.rsvd.limit_in_bytes diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 4f400b03dddf..5aa368d165da 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2266,6 +2266,11 @@ HugeTLB Interface Files are local to the cgroup i.e. not hierarchical. The file modified event generated on this file reflects only the local events. + hugetlb..numa_stat + Similar to memory.numa_stat, it shows the numa information of the + hugetlb pages of in this cgroup. Only active in + use hugetlb pages are included. The per-node values are in bytes. + Misc ---- diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 00351ccb49a3..d1897a69c540 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -622,8 +622,8 @@ struct hstate { #endif #ifdef CONFIG_CGROUP_HUGETLB /* cgroup control files */ - struct cftype cgroup_files_dfl[7]; - struct cftype cgroup_files_legacy[9]; + struct cftype cgroup_files_dfl[8]; + struct cftype cgroup_files_legacy[10]; #endif char name[HSTATE_NAME_LEN]; }; diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h index ba025ae27882..379344828e78 100644 --- a/include/linux/hugetlb_cgroup.h +++ b/include/linux/hugetlb_cgroup.h @@ -36,6 +36,11 @@ enum hugetlb_memory_event { HUGETLB_NR_MEMORY_EVENTS, }; +struct hugetlb_cgroup_per_node { + /* hugetlb usage in pages over all hstates. */ + unsigned long usage[HUGE_MAX_HSTATE]; +}; + struct hugetlb_cgroup { struct cgroup_subsys_state css; @@ -57,6 +62,8 @@ struct hugetlb_cgroup { /* Handle for "hugetlb.events.local" */ struct cgroup_file events_local_file[HUGE_MAX_HSTATE]; + + struct hugetlb_cgroup_per_node *nodeinfo[]; }; static inline struct hugetlb_cgroup * diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 79d93534ef1e..f9942841df18 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -123,29 +123,58 @@ static void hugetlb_cgroup_init(struct hugetlb_cgroup *h_cgroup, } } +static void hugetlb_cgroup_free(struct hugetlb_cgroup *h_cgroup) +{ + int node; + + for_each_node(node) + kfree(h_cgroup->nodeinfo[node]); + kfree(h_cgroup); +} + 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; + int node; + + h_cgroup = kzalloc(struct_size(h_cgroup, nodeinfo, nr_node_ids), + GFP_KERNEL); - h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL); if (!h_cgroup) return ERR_PTR(-ENOMEM); if (!parent_h_cgroup) root_h_cgroup = h_cgroup; + /* + * TODO: this routine can waste much memory for nodes which will + * never be onlined. It's better to use memory hotplug callback + * function. + */ + for_each_node(node) { + /* Set node_to_alloc to -1 for offline nodes. */ + int node_to_alloc = + node_state(node, N_NORMAL_MEMORY) ? node : -1; + h_cgroup->nodeinfo[node] = + kzalloc_node(sizeof(struct hugetlb_cgroup_per_node), + GFP_KERNEL, node_to_alloc); + if (!h_cgroup->nodeinfo[node]) + goto fail_alloc_nodeinfo; + } + hugetlb_cgroup_init(h_cgroup, parent_h_cgroup); return &h_cgroup->css; + +fail_alloc_nodeinfo: + hugetlb_cgroup_free(h_cgroup); + return ERR_PTR(-ENOMEM); } 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); + hugetlb_cgroup_free(hugetlb_cgroup_from_css(css)); } /* @@ -289,7 +318,17 @@ static void __hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, return; __set_hugetlb_cgroup(page, h_cg, rsvd); - return; + if (!rsvd) { + unsigned long usage = + h_cg->nodeinfo[page_to_nid(page)]->usage[idx]; + /* + * This write is not atomic due to fetching usage and writing + * to it, but that's fine because we call this with + * hugetlb_lock held anyway. + */ + WRITE_ONCE(h_cg->nodeinfo[page_to_nid(page)]->usage[idx], + usage + nr_pages); + } } void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, @@ -328,8 +367,17 @@ static void __hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, if (rsvd) css_put(&h_cg->css); - - return; + else { + unsigned long usage = + h_cg->nodeinfo[page_to_nid(page)]->usage[idx]; + /* + * This write is not atomic due to fetching usage and writing + * to it, but that's fine because we call this with + * hugetlb_lock held anyway. + */ + WRITE_ONCE(h_cg->nodeinfo[page_to_nid(page)]->usage[idx], + usage - nr_pages); + } } void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, @@ -418,6 +466,59 @@ enum { RES_RSVD_FAILCNT, }; +static int hugetlb_cgroup_read_numa_stat(struct seq_file *seq, void *dummy) +{ + int nid; + struct cftype *cft = seq_cft(seq); + int idx = MEMFILE_IDX(cft->private); + bool legacy = MEMFILE_ATTR(cft->private); + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq)); + struct cgroup_subsys_state *css; + unsigned long usage; + + if (legacy) { + /* Add up usage across all nodes for the non-hierarchical total. */ + usage = 0; + for_each_node_state(nid, N_MEMORY) + usage += READ_ONCE(h_cg->nodeinfo[nid]->usage[idx]); + seq_printf(seq, "total=%lu", usage * PAGE_SIZE); + + /* Simply print the per-node usage for the non-hierarchical total. */ + for_each_node_state(nid, N_MEMORY) + seq_printf(seq, " N%d=%lu", nid, + READ_ONCE(h_cg->nodeinfo[nid]->usage[idx]) * + PAGE_SIZE); + seq_putc(seq, '\n'); + } + + /* + * The hierarchical total is pretty much the value recorded by the + * counter, so use that. + */ + seq_printf(seq, "%stotal=%lu", legacy ? "hierarchical_" : "", + page_counter_read(&h_cg->hugepage[idx]) * PAGE_SIZE); + + /* + * For each node, transverse the css tree to obtain the hierarchical + * node usage. + */ + for_each_node_state(nid, N_MEMORY) { + usage = 0; + rcu_read_lock(); + css_for_each_descendant_pre(css, &h_cg->css) { + usage += READ_ONCE(hugetlb_cgroup_from_css(css) + ->nodeinfo[nid] + ->usage[idx]); + } + rcu_read_unlock(); + seq_printf(seq, " N%d=%lu", nid, usage * PAGE_SIZE); + } + + seq_putc(seq, '\n'); + + return 0; +} + static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css, struct cftype *cft) { @@ -668,8 +769,14 @@ static void __init __hugetlb_cgroup_file_dfl_init(int idx) events_local_file[idx]); cft->flags = CFTYPE_NOT_ON_ROOT; - /* NULL terminate the last cft */ + /* Add the numa stat file */ cft = &h->cgroup_files_dfl[6]; + snprintf(cft->name, MAX_CFTYPE_NAME, "%s.numa_stat", buf); + cft->seq_show = hugetlb_cgroup_read_numa_stat; + cft->flags = CFTYPE_NOT_ON_ROOT; + + /* NULL terminate the last cft */ + cft = &h->cgroup_files_dfl[7]; memset(cft, 0, sizeof(*cft)); WARN_ON(cgroup_add_dfl_cftypes(&hugetlb_cgrp_subsys, @@ -739,8 +846,14 @@ static void __init __hugetlb_cgroup_file_legacy_init(int idx) cft->write = hugetlb_cgroup_reset; cft->read_u64 = hugetlb_cgroup_read_u64; - /* NULL terminate the last cft */ + /* Add the numa stat file */ cft = &h->cgroup_files_legacy[8]; + snprintf(cft->name, MAX_CFTYPE_NAME, "%s.numa_stat", buf); + cft->private = MEMFILE_PRIVATE(idx, 1); + cft->seq_show = hugetlb_cgroup_read_numa_stat; + + /* NULL terminate the last cft */ + cft = &h->cgroup_files_legacy[9]; memset(cft, 0, sizeof(*cft)); WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys,