From ed2da8b725b932b1e2b2f4835bb664d47ed03031 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 10 Oct 2023 09:31:40 +0100 Subject: sched/numa: Trace decisions related to skipping VMAs NUMA balancing skips or scans VMAs for a variety of reasons. In preparation for completing scans of VMAs regardless of PID access, trace the reasons why a VMA was skipped. In a later patch, the tracing will be used to track if a VMA was forcibly scanned. Signed-off-by: Mel Gorman Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20231010083143.19593-4-mgorman@techsingularity.net --- kernel/sched/fair.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'kernel/sched') diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6b47edcbe834..31cfdb0794fb 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3210,6 +3210,7 @@ static void task_numa_work(struct callback_head *work) do { if (!vma_migratable(vma) || !vma_policy_mof(vma) || is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) { + trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_UNSUITABLE); continue; } @@ -3220,15 +3221,19 @@ static void task_numa_work(struct callback_head *work) * as migrating the pages will be of marginal benefit. */ if (!vma->vm_mm || - (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ))) + (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ))) { + trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_SHARED_RO); continue; + } /* * Skip inaccessible VMAs to avoid any confusion between * PROT_NONE and NUMA hinting ptes */ - if (!vma_is_accessible(vma)) + if (!vma_is_accessible(vma)) { + trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_INACCESSIBLE); continue; + } /* Initialise new per-VMA NUMAB state. */ if (!vma->numab_state) { @@ -3250,12 +3255,16 @@ static void task_numa_work(struct callback_head *work) * delay the scan for new VMAs. */ if (mm->numa_scan_seq && time_before(jiffies, - vma->numab_state->next_scan)) + vma->numab_state->next_scan)) { + trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_SCAN_DELAY); continue; + } /* Do not scan the VMA if task has not accessed */ - if (!vma_is_accessed(vma)) + if (!vma_is_accessed(vma)) { + trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_PID_INACTIVE); continue; + } /* * RESET access PIDs regularly for old VMAs. Resetting after checking -- cgit v1.2.3