Messages in this thread Patch in this message | | | From | Bharata B Rao <> | Subject | [RFC PATCH v0 2/3] sched/numa: Add cumulative history of per-process fault stats | Date | Fri, 28 Jan 2022 10:58:50 +0530 |
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From: Disha Talreja <dishaa.talreja@amd.com>
The cumulative history of local/remote (lr) and private/shared (ps) will be used for calculating adaptive scan period.
Co-developed-by: Wei Huang <wei.huang2@amd.com> Signed-off-by: Wei Huang <wei.huang2@amd.com> Signed-off-by: Disha Talreja <dishaa.talreja@amd.com> Signed-off-by: Bharata B Rao <bharata@amd.com> --- include/linux/mm_types.h | 2 ++ kernel/sched/fair.c | 49 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 50 insertions(+), 1 deletion(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 4f978c09d3db..2c6f119b947f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -614,6 +614,8 @@ struct mm_struct { /* Process-based Adaptive NUMA */ atomic_long_t faults_locality[2]; atomic_long_t faults_shared[2]; + unsigned long faults_locality_history[2]; + unsigned long faults_shared_history[2]; spinlock_t pan_numa_lock; unsigned int numa_scan_period; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 1d6404b2d42e..4911b3841d00 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2102,14 +2102,56 @@ static void numa_group_count_active_nodes(struct numa_group *numa_group) /**********************************************/ /* Process-based Adaptive NUMA (PAN) Design */ /**********************************************/ +/* + * Update the cumulative history of local/remote and private/shared + * statistics. If the numbers are too small worthy of updating, + * return FALSE, otherwise return TRUE. + */ +static bool pan_update_history(struct task_struct *p) +{ + unsigned long local, remote, shared, private; + long diff; + int i; + + remote = atomic_long_read(&p->mm->faults_locality[0]); + local = atomic_long_read(&p->mm->faults_locality[1]); + shared = atomic_long_read(&p->mm->faults_shared[0]); + private = atomic_long_read(&p->mm->faults_shared[1]); + + /* skip if the activities in this window are too small */ + if (local + remote < 100) + return false; + + /* decay over the time window by 1/4 */ + diff = local - (long)(p->mm->faults_locality_history[1] / 4); + p->mm->faults_locality_history[1] += diff; + diff = remote - (long)(p->mm->faults_locality_history[0] / 4); + p->mm->faults_locality_history[0] += diff; + + /* decay over the time window by 1/2 */ + diff = shared - (long)(p->mm->faults_shared_history[0] / 2); + p->mm->faults_shared_history[0] += diff; + diff = private - (long)(p->mm->faults_shared_history[1] / 2); + p->mm->faults_shared_history[1] += diff; + + /* clear the statistics for the next window */ + for (i = 0; i < 2; i++) { + atomic_long_set(&(p->mm->faults_locality[i]), 0); + atomic_long_set(&(p->mm->faults_shared[i]), 0); + } + + return true; +} + /* * Updates mm->numa_scan_period under mm->pan_numa_lock. - * * Returns p->numa_scan_period now but updated to return * p->mm->numa_scan_period in a later patch. */ static unsigned long pan_get_scan_period(struct task_struct *p) { + pan_update_history(p); + return p->numa_scan_period; } @@ -2836,10 +2878,15 @@ static void task_numa_work(struct callback_head *work) static void pan_init_numa(struct task_struct *p) { struct mm_struct *mm = p->mm; + int i; spin_lock_init(&mm->pan_numa_lock); mm->numa_scan_period = sysctl_numa_balancing_scan_delay; + for (i = 0; i < 2; i++) { + mm->faults_locality_history[i] = 0; + mm->faults_shared_history[i] = 0; + } } void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) -- 2.25.1
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