From: Mel Gorman <mgorman@techsingularity.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Bharata B Rao <bharata@amd.com>, Ingo Molnar <mingo@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 0/6] sched/numa: Complete scanning of partial and inactive VMAs
Date: Tue, 10 Oct 2023 09:31:37 +0100 [thread overview]
Message-ID: <20231010083143.19593-1-mgorman@techsingularity.net> (raw)
NUMA Balancing currently uses PID fault activity within a VMA to
determine if it is worth updating PTEs to trap NUMA hinting faults.
While this is reduces overhead, it misses two important corner case.
The first is that if Task A partially scans a VMA that is active and
Task B resumes the scan but is inactive, then the remainder of the VMA
may be missed. Similarly, if a VMA is inactive for a period of time then
it may never be scanned again.
Patches 1-3 improve the documentation of the current per-VMA tracking
and adds a trace point for scan activity. Patch 4 addresses a corner
case where the PID activity information may not be reset after the
expected timeout. Patches 5-6 complete the scanning of partial and
inactive VMAs within the scan sequence.
This could be improved further but it would deserve a separate series on
top with supporting data justifying the change. Otherwise and gain/loss
due to the additional changes could be masked by this series on its own.
include/linux/mm.h | 4 +-
include/linux/mm_types.h | 36 +++++++++-
include/linux/sched/numa_balancing.h | 10 +++
include/trace/events/sched.h | 52 ++++++++++++++
kernel/sched/fair.c | 103 ++++++++++++++++++++++-----
5 files changed, 182 insertions(+), 23 deletions(-)
--
2.35.3
next reply other threads:[~2023-10-10 8:32 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-10 8:31 Mel Gorman [this message]
2023-10-10 8:31 ` [PATCH 1/6] sched/numa: Document vma_numab_state fields Mel Gorman
2023-10-10 9:43 ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10 8:31 ` [PATCH 2/6] sched/numa: Rename vma_numab_state.access_pids Mel Gorman
2023-10-10 9:43 ` [tip: sched/core] sched/numa: Rename vma_numab_state::access_pids[] => ::pids_active[], ::next_pid_reset => ::pids_active_reset tip-bot2 for Mel Gorman
2023-10-10 8:31 ` [PATCH 3/6] sched/numa: Trace decisions related to skipping VMAs Mel Gorman
2023-10-10 9:43 ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10 8:31 ` [PATCH 4/6] sched/numa: Move up the access pid reset logic Mel Gorman
2023-10-10 9:43 ` [tip: sched/core] " tip-bot2 for Raghavendra K T
2023-10-10 8:31 ` [PATCH 5/6] sched/numa: Complete scanning of partial VMAs regardless of PID activity Mel Gorman
2023-10-10 9:43 ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10 21:47 ` tip-bot2 for Mel Gorman
2023-10-10 8:31 ` [PATCH 6/6] sched/numa: Complete scanning of inactive VMAs when there is no alternative Mel Gorman
2023-10-10 9:23 ` Ingo Molnar
2023-10-10 9:57 ` Mel Gorman
2023-10-10 21:39 ` Ingo Molnar
2023-10-10 11:40 ` Raghavendra K T
2024-02-24 4:50 ` Raghavendra K T
2023-10-10 9:43 ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10 11:42 ` [PATCH 6/6] " Raghavendra K T
2023-10-10 21:47 ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10 11:39 ` [PATCH 0/6] sched/numa: Complete scanning of partial and inactive VMAs Raghavendra K T
2023-10-10 21:45 ` Ingo Molnar
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