Commit 2e2675db authored by Raghavendra K T's avatar Raghavendra K T Committed by Ingo Molnar
Browse files

sched/numa: Move up the access pid reset logic 



Recent NUMA hinting faulting activity is reset approximately every
VMA_PID_RESET_PERIOD milliseconds. However, if the current task has not
accessed a VMA then the reset check is missed and the reset is potentially
deferred forever. Check if the PID activity information should be reset
before checking if the current task recently trapped a NUMA hinting fault.

[ mgorman@techsingularity.net: Rewrite changelog ]

Suggested-by: default avatarMel Gorman <mgorman@techsingularity.net>
Signed-off-by: default avatarRaghavendra K T <raghavendra.kt@amd.com>
Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20231010083143.19593-5-mgorman@techsingularity.net
parent ed2da8b7

kernel/sched/fair.c

+7 −10
Original line number Diff line number Diff line
@@ -3260,16 +3260,7 @@ static void task_numa_work(struct callback_head *work) 
			continue;

		}



		/* Do not scan the VMA if task has not accessed */

		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

		 * vma for recent access to avoid clearing PID info before access..

		 */

		/* RESET access PIDs regularly for old VMAs. */

		if (mm->numa_scan_seq &&

				time_after(jiffies, vma->numab_state->pids_active_reset)) {

			vma->numab_state->pids_active_reset = vma->numab_state->pids_active_reset +
@@ -3278,6 +3269,12 @@ static void task_numa_work(struct callback_head *work) 
			vma->numab_state->pids_active[1] = 0;

		}



		/* Do not scan the VMA if task has not accessed */

		if (!vma_is_accessed(vma)) {

			trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_PID_INACTIVE);

			continue;

		}



		do {

			start = max(start, vma->vm_start);

			end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);