This patch add a new api PR_PROCESS_NUMAB in prctl. A large number of page faults will cause performance loss when numa balancing is performing. Thus those processes which care about worst-case performance need numa balancing disabled. Others, on the contrary, allow a temporary performance loss in exchange for higher average performance, so enable numa balancing is better for them. Numa balancing can only be controlled globally by /proc/sys/kernel/numa_balancing. Due to the above case, we want to disable/enable numa_balancing per-process instead. Add numa_balancing under mm_struct. Then use it in task_tick_fair. Set per-process numa balancing: prctl(PR_PROCESS_NUMAB, PR_SET_PROCESS_NUMAB_DISABLED); prctl(PR_PROCESS_NUMAB, PR_SET_PROCESS_NUMAB_ENABLED); prctl(PR_PROCESS_NUMAB, PR_SET_PROCESS_NUMAB_DEFAULT); Get numa_balancing state: prctl(PR_PROCESS_NUMAB, PR_GET_PROCESS_NUMAB, &ret); cat /proc/<pid>/status | grep NumaB_enabled Cc: linux-api@xxxxxxxxxxxxxxx Signed-off-by: Gang Li <ligang.bdlg@xxxxxxxxxxxxx> --- Changes in v4: - Adaptation of new feature: optimize page placement for memory tiering system. https://lore.kernel.org/all/20220128082751.593478-3-ying.huang@xxxxxxxxx/ - warp sched_numa_balancing and mm->numab_enabled with process_sched_numab_enabled(). Changes in v3: - Fix compile error. Changes in v2: - Now PR_NUMA_BALANCING support three states: enabled, disabled, default. enabled and disabled will ignore global setting, and default will follow global setting. --- Documentation/filesystems/proc.rst | 2 ++ fs/proc/task_mmu.c | 19 +++++++++++++++ include/linux/mm_types.h | 3 +++ include/linux/sched/numa_balancing.h | 6 +++++ include/linux/sched/sysctl.h | 19 +++++++++++++++ include/uapi/linux/prctl.h | 7 ++++++ kernel/fork.c | 3 +++ kernel/sched/fair.c | 34 ++++++++++++++++++++++----- kernel/sys.c | 35 ++++++++++++++++++++++++++++ mm/huge_memory.c | 2 +- mm/mprotect.c | 6 ++--- 11 files changed, 126 insertions(+), 10 deletions(-) diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index 061744c436d9..00f6503f0793 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -192,6 +192,7 @@ read the file /proc/PID/status:: VmLib: 1412 kB VmPTE: 20 kb VmSwap: 0 kB + NumaB_enabled: default HugetlbPages: 0 kB CoreDumping: 0 THP_enabled: 1 @@ -273,6 +274,7 @@ It's slow but very precise. VmPTE size of page table entries VmSwap amount of swap used by anonymous private data (shmem swap usage is not included) + NumaB_enabled numa balancing state, set by prctl(PR_PROCESS_NUMAB, ...) HugetlbPages size of hugetlb memory portions CoreDumping process's memory is currently being dumped (killing the process may lead to a corrupted core) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 6e97ed775074..b1aa100b8711 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -20,6 +20,7 @@ #include <linux/shmem_fs.h> #include <linux/uaccess.h> #include <linux/pkeys.h> +#include <linux/sched/numa_balancing.h> #include <asm/elf.h> #include <asm/tlb.h> @@ -76,6 +77,24 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8); SEQ_PUT_DEC(" kB\nVmSwap:\t", swap); seq_puts(m, " kB\n"); +#ifdef CONFIG_NUMA_BALANCING + seq_puts(m, "NumaB_enabled:\t"); + switch (mm->numab_enabled) { + case PROCESS_NUMAB_DEFAULT: + seq_puts(m, "default"); + break; + case PROCESS_NUMAB_DISABLED: + seq_puts(m, "disabled"); + break; + case PROCESS_NUMAB_ENABLED: + seq_puts(m, "enabled"); + break; + default: + seq_puts(m, "unknown"); + break; + } + seq_putc(m, '\n'); +#endif hugetlb_report_usage(m, mm); } #undef SEQ_PUT_DEC diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 9f05ffa12265..5a42aba3b17f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -626,6 +626,9 @@ struct mm_struct { /* numa_scan_seq prevents two threads setting pte_numa */ int numa_scan_seq; + + /* Controls whether NUMA balancing is active for this mm. */ + int numab_enabled; #endif /* * An operation with batched TLB flushing is going on. Anything diff --git a/include/linux/sched/numa_balancing.h b/include/linux/sched/numa_balancing.h index 3988762efe15..c7dc08d6ba6a 100644 --- a/include/linux/sched/numa_balancing.h +++ b/include/linux/sched/numa_balancing.h @@ -16,6 +16,12 @@ #define TNF_MIGRATE_FAIL 0x10 #ifdef CONFIG_NUMA_BALANCING +enum { + PROCESS_NUMAB_DISABLED, + PROCESS_NUMAB_ENABLED, + PROCESS_NUMAB_DEFAULT +}; +DECLARE_STATIC_KEY_FALSE(sched_numa_balancing); extern void task_numa_fault(int last_node, int node, int pages, int flags); extern pid_t task_numa_group_id(struct task_struct *p); extern void set_numabalancing_state(bool enabled); diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index c1076b5e17fb..77d010942481 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -3,6 +3,7 @@ #define _LINUX_SCHED_SYSCTL_H #include <linux/types.h> +#include <linux/sched/numa_balancing.h> struct ctl_table; @@ -29,8 +30,26 @@ enum sched_tunable_scaling { #ifdef CONFIG_NUMA_BALANCING extern int sysctl_numa_balancing_mode; +static inline int process_sysctl_numab_mode(struct mm_struct *mm) +{ + int numab = mm->numab_enabled; + + switch (numab) { + case PROCESS_NUMAB_ENABLED: + return NUMA_BALANCING_NORMAL; + case PROCESS_NUMAB_DISABLED: + return NUMA_BALANCING_DISABLED; + case PROCESS_NUMAB_DEFAULT: + default: + return sysctl_numa_balancing_mode; + } +} #else #define sysctl_numa_balancing_mode 0 +static inline int process_sysctl_numab_mode(struct mm_struct *mm) +{ + return NUMA_BALANCING_DISABLED; +} #endif /* diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index e998764f0262..d06a904c35c1 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -275,4 +275,11 @@ struct prctl_mm_map { #define PR_SET_VMA 0x53564d41 # define PR_SET_VMA_ANON_NAME 0 +/* Set/get enabled per-process numa_balancing */ +#define PR_PROCESS_NUMAB 63 +# define PR_SET_PROCESS_NUMAB_DISABLED PROCESS_NUMAB_DISABLED +# define PR_SET_PROCESS_NUMAB_ENABLED PROCESS_NUMAB_ENABLED +# define PR_SET_PROCESS_NUMAB_DEFAULT PROCESS_NUMAB_DEFAULT +# define PR_GET_PROCESS_NUMAB 3 + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/fork.c b/kernel/fork.c index 64dbfb9426fd..2f93b240ebab 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1059,6 +1059,9 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, init_tlb_flush_pending(mm); #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS mm->pmd_huge_pte = NULL; +#endif +#ifdef CONFIG_NUMA_BALANCING + mm->numab_enabled = PROCESS_NUMAB_DEFAULT; #endif mm_init_uprobes_state(mm); hugetlb_count_init(mm); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 28b91f11b618..7ff5831c5b33 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2575,6 +2575,23 @@ void task_numa_free(struct task_struct *p, bool final) } } +static inline bool process_sched_numab_enabled(struct task_struct *p) +{ + if (p->mm) { + int numab = p->mm->numab_enabled; + + switch (numab) { + case PROCESS_NUMAB_ENABLED: + return true; + case PROCESS_NUMAB_DISABLED: + return false; + case PROCESS_NUMAB_DEFAULT: + break; + } + } + return static_branch_unlikely(&sched_numa_balancing); +} + /* * Got a PROT_NONE fault for a page on @node. */ @@ -2587,13 +2604,13 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags) struct numa_group *ng; int priv; - if (!static_branch_likely(&sched_numa_balancing)) - return; - /* for example, ksmd faulting in a user's mm */ if (!p->mm) return; + if (!process_sched_numab_enabled(p)) + return; + /* Allocate buffer to track faults on a per-node basis */ if (unlikely(!p->numa_faults)) { int size = sizeof(*p->numa_faults) * @@ -2894,7 +2911,7 @@ static void update_scan_period(struct task_struct *p, int new_cpu) int src_nid = cpu_to_node(task_cpu(p)); int dst_nid = cpu_to_node(new_cpu); - if (!static_branch_likely(&sched_numa_balancing)) + if (!process_sched_numab_enabled(p)) return; if (!p->mm || !p->numa_faults || (p->flags & PF_EXITING)) @@ -2928,6 +2945,11 @@ static void task_tick_numa(struct rq *rq, struct task_struct *curr) { } +static inline bool process_sched_numab_enabled(struct task_struct *p) +{ + return false; +} + static inline void account_numa_enqueue(struct rq *rq, struct task_struct *p) { } @@ -7687,7 +7709,7 @@ static int migrate_degrades_locality(struct task_struct *p, struct lb_env *env) unsigned long src_weight, dst_weight; int src_nid, dst_nid, dist; - if (!static_branch_likely(&sched_numa_balancing)) + if (!process_sched_numab_enabled(p)) return -1; if (!p->numa_faults || !(env->sd->flags & SD_NUMA)) @@ -11164,7 +11186,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) entity_tick(cfs_rq, se, queued); } - if (static_branch_unlikely(&sched_numa_balancing)) + if (process_sched_numab_enabled(curr)) task_tick_numa(rq, curr); update_misfit_status(curr, rq); diff --git a/kernel/sys.c b/kernel/sys.c index ecc4cf019242..04cb73e39926 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -58,6 +58,7 @@ #include <linux/sched/coredump.h> #include <linux/sched/task.h> #include <linux/sched/cputime.h> +#include <linux/sched/numa_balancing.h> #include <linux/rcupdate.h> #include <linux/uidgid.h> #include <linux/cred.h> @@ -2081,6 +2082,23 @@ static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, return 0; } +#ifdef CONFIG_NUMA_BALANCING +static int prctl_pid_numa_balancing_write(int numa_balancing) +{ + if (numa_balancing != PR_SET_PROCESS_NUMAB_DEFAULT + && numa_balancing != PR_SET_PROCESS_NUMAB_DISABLED + && numa_balancing != PR_SET_PROCESS_NUMAB_ENABLED) + return -EINVAL; + current->mm->numab_enabled = numa_balancing; + return 0; +} + +static int prctl_pid_numa_balancing_read(void) +{ + return current->mm->numab_enabled; +} +#endif + static int prctl_set_mm(int opt, unsigned long addr, unsigned long arg4, unsigned long arg5) { @@ -2585,6 +2603,23 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, error = set_syscall_user_dispatch(arg2, arg3, arg4, (char __user *) arg5); break; +#ifdef CONFIG_NUMA_BALANCING + case PR_PROCESS_NUMAB: + switch (arg2) { + case PR_SET_PROCESS_NUMAB_DEFAULT: + case PR_SET_PROCESS_NUMAB_DISABLED: + case PR_SET_PROCESS_NUMAB_ENABLED: + error = prctl_pid_numa_balancing_write((int)arg2); + break; + case PR_GET_PROCESS_NUMAB: + error = put_user(prctl_pid_numa_balancing_read(), (int __user *)arg3); + break; + default: + error = -EINVAL; + break; + } + break; +#endif #ifdef CONFIG_SCHED_CORE case PR_SCHED_CORE: error = sched_core_share_pid(arg2, arg3, arg4, arg5); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 09fb65a80e63..25a660065af1 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1760,7 +1760,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, * Skip scanning top tier node if normal numa * balancing is disabled */ - if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) && + if (!(process_sysctl_numab_mode(vma->vm_mm) & NUMA_BALANCING_NORMAL) && node_is_toptier(page_to_nid(page))) goto unlock; } diff --git a/mm/mprotect.c b/mm/mprotect.c index 2fe03e695c81..2ae0127f46e8 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -33,7 +33,7 @@ #include <asm/cacheflush.h> #include <asm/mmu_context.h> #include <asm/tlbflush.h> - +#include <linux/sched/numa_balancing.h> #include "internal.h" static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, @@ -119,8 +119,8 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, * Skip scanning top tier node if normal numa * balancing is disabled */ - if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) && - node_is_toptier(nid)) + if (!(process_sysctl_numab_mode(vma->vm_mm) & NUMA_BALANCING_NORMAL) + && node_is_toptier(nid)) continue; } -- 2.20.1
