From 5f69a6577bc33d8f6d6bbe02bccdeb357b287f56 Mon Sep 17 00:00:00 2001 From: Chen Wandun Date: Thu, 26 May 2022 20:26:56 +0800 Subject: [PATCH] psi: dont alloc memory for psi by default Memory about struct psi_group is allocated by default for each cgroup even if psi_disabled is true, in this case, these allocated memory is waste, so alloc memory for struct psi_group only when psi_disabled is false. Signed-off-by: Chen Wandun Acked-by: Johannes Weiner Signed-off-by: Tejun Heo --- include/linux/cgroup-defs.h | 2 +- include/linux/cgroup.h | 2 +- kernel/cgroup/cgroup.c | 8 ++++---- kernel/sched/psi.c | 19 +++++++++++++------ 4 files changed, 19 insertions(+), 12 deletions(-) diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 1bfcfb1af352..672de25e3ec8 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -475,7 +475,7 @@ struct cgroup { struct work_struct release_agent_work; /* used to track pressure stalls */ - struct psi_group psi; + struct psi_group *psi; /* used to store eBPF programs */ struct cgroup_bpf bpf; diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 0d1ada8968d7..ed53bfe7c46c 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -674,7 +674,7 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp) static inline struct psi_group *cgroup_psi(struct cgroup *cgrp) { - return &cgrp->psi; + return cgrp->psi; } bool cgroup_psi_enabled(void); diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 1779ccddb734..90a654cb8a1e 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -3609,21 +3609,21 @@ static int cpu_stat_show(struct seq_file *seq, void *v) static int cgroup_io_pressure_show(struct seq_file *seq, void *v) { struct cgroup *cgrp = seq_css(seq)->cgroup; - struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi; + struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi; return psi_show(seq, psi, PSI_IO); } static int cgroup_memory_pressure_show(struct seq_file *seq, void *v) { struct cgroup *cgrp = seq_css(seq)->cgroup; - struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi; + struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi; return psi_show(seq, psi, PSI_MEM); } static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v) { struct cgroup *cgrp = seq_css(seq)->cgroup; - struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi; + struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi; return psi_show(seq, psi, PSI_CPU); } @@ -3649,7 +3649,7 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf, return -EBUSY; } - psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi; + psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi; new = psi_trigger_create(psi, buf, nbytes, res); if (IS_ERR(new)) { cgroup_put(cgrp); diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index a337f3e35997..ec66b40bdd40 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -957,10 +957,16 @@ int psi_cgroup_alloc(struct cgroup *cgroup) if (static_branch_likely(&psi_disabled)) return 0; - cgroup->psi.pcpu = alloc_percpu(struct psi_group_cpu); - if (!cgroup->psi.pcpu) + cgroup->psi = kmalloc(sizeof(struct psi_group), GFP_KERNEL); + if (!cgroup->psi) return -ENOMEM; - group_init(&cgroup->psi); + + cgroup->psi->pcpu = alloc_percpu(struct psi_group_cpu); + if (!cgroup->psi->pcpu) { + kfree(cgroup->psi); + return -ENOMEM; + } + group_init(cgroup->psi); return 0; } @@ -969,10 +975,11 @@ void psi_cgroup_free(struct cgroup *cgroup) if (static_branch_likely(&psi_disabled)) return; - cancel_delayed_work_sync(&cgroup->psi.avgs_work); - free_percpu(cgroup->psi.pcpu); + cancel_delayed_work_sync(&cgroup->psi->avgs_work); + free_percpu(cgroup->psi->pcpu); /* All triggers must be removed by now */ - WARN_ONCE(cgroup->psi.poll_states, "psi: trigger leak\n"); + WARN_ONCE(cgroup->psi->poll_states, "psi: trigger leak\n"); + kfree(cgroup->psi); } /**