diff --git a/include/linux/mm.h b/include/linux/mm.h index 215327daffae..e05a878e186e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1692,8 +1692,8 @@ static inline void vma_set_access_pid_bit(struct vm_area_struct *vma) unsigned int pid_bit; pid_bit = current->pid % BITS_PER_LONG; - if (vma->numab_state && !test_bit(pid_bit, &vma->numab_state->access_pids)) { - __set_bit(pid_bit, &vma->numab_state->access_pids); + if (vma->numab_state && !test_bit(pid_bit, &vma->numab_state->access_pids[1])) { + __set_bit(pid_bit, &vma->numab_state->access_pids[1]); } } #else /* !CONFIG_NUMA_BALANCING */ diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index f8cbd8efc7cb..092f842a854f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -477,7 +477,8 @@ struct vma_lock { struct vma_numab_state { unsigned long next_scan; - unsigned long access_pids; + unsigned long next_pid_reset; + unsigned long access_pids[2]; }; /* diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index ef27b5931480..a962d4b60cd7 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2930,6 +2930,7 @@ static void reset_ptenuma_scan(struct task_struct *p) static bool vma_is_accessed(struct vm_area_struct *vma) { + unsigned long pids; /* * Allow unconditional access first two times, so that all the (pages) * of VMAs get prot_none fault introduced irrespective of accesses. @@ -2939,10 +2940,12 @@ static bool vma_is_accessed(struct vm_area_struct *vma) if (READ_ONCE(current->mm->numa_scan_seq) < 2) return true; - return test_bit(current->pid % BITS_PER_LONG, - &vma->numab_state->access_pids); + pids = vma->numab_state->access_pids[0] | vma->numab_state->access_pids[1]; + return test_bit(current->pid % BITS_PER_LONG, &pids); } +#define VMA_PID_RESET_PERIOD (4 * sysctl_numa_balancing_scan_delay) + /* * The expensive part of numa migration is done from task_work context. * Triggered from task_tick_numa(). @@ -3051,6 +3054,10 @@ static void task_numa_work(struct callback_head *work) vma->numab_state->next_scan = now + msecs_to_jiffies(sysctl_numa_balancing_scan_delay); + + /* Reset happens after 4 times scan delay of scan start */ + vma->numab_state->next_pid_reset = vma->numab_state->next_scan + + msecs_to_jiffies(VMA_PID_RESET_PERIOD); } /* @@ -3065,6 +3072,18 @@ static void task_numa_work(struct callback_head *work) if (!vma_is_accessed(vma)) continue; + /* + * RESET access PIDs regularly for old VMAs. Resetting after checking + * vma for recent access to avoid clearing PID info before access.. + */ + if (mm->numa_scan_seq && + time_after(jiffies, vma->numab_state->next_pid_reset)) { + vma->numab_state->next_pid_reset = vma->numab_state->next_pid_reset + + msecs_to_jiffies(VMA_PID_RESET_PERIOD); + vma->numab_state->access_pids[0] = READ_ONCE(vma->numab_state->access_pids[1]); + vma->numab_state->access_pids[1] = 0; + } + do { start = max(start, vma->vm_start); end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);