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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-22 14:39:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-22 14:39:12 -0700
commit3fe2f7446f1e029b220f7f650df6d138f91651f2 (patch)
treebc6f9adc91f9e4fd4d78f49f1188388ebfa90bcb /Documentation/admin-guide
parentebd326ce724d5b2e5274724e6d6a46a046e28203 (diff)
parentffea9fb319360b9ead8befac6bb2db2b54fd53e6 (diff)
Merge tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: - Cleanups for SCHED_DEADLINE - Tracing updates/fixes - CPU Accounting fixes - First wave of changes to optimize the overhead of the scheduler build, from the fast-headers tree - including placeholder *_api.h headers for later header split-ups. - Preempt-dynamic using static_branch() for ARM64 - Isolation housekeeping mask rework; preperatory for further changes - NUMA-balancing: deal with CPU-less nodes - NUMA-balancing: tune systems that have multiple LLC cache domains per node (eg. AMD) - Updates to RSEQ UAPI in preparation for glibc usage - Lots of RSEQ/selftests, for same - Add Suren as PSI co-maintainer * tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits) sched/headers: ARM needs asm/paravirt_api_clock.h too sched/numa: Fix boot crash on arm64 systems headers/prep: Fix header to build standalone: <linux/psi.h> sched/headers: Only include <linux/entry-common.h> when CONFIG_GENERIC_ENTRY=y cgroup: Fix suspicious rcu_dereference_check() usage warning sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers sched/topology: Remove redundant variable and fix incorrect type in build_sched_domains sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity() sched/deadline,rt: Remove unused functions for !CONFIG_SMP sched/deadline: Use __node_2_[pdl|dle]() and rb_first_cached() consistently sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy() sched/deadline: Move bandwidth mgmt and reclaim functions into sched class source file sched/deadline: Remove unused def_dl_bandwidth sched/tracing: Report TASK_RTLOCK_WAIT tasks as TASK_UNINTERRUPTIBLE sched/tracing: Don't re-read p->state when emitting sched_switch event sched/rt: Plug rt_mutex_setprio() vs push_rt_task() race sched/cpuacct: Remove redundant RCU read lock sched/cpuacct: Optimize away RCU read lock sched/cpuacct: Fix charge percpu cpuusage sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies ...
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/sysctl/kernel.rst46
1 files changed, 1 insertions, 45 deletions
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 5dd660aac0ae..2d1b8c1ea2e8 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -609,51 +609,7 @@ be migrated to a local memory node.
The unmapping of pages and trapping faults incur additional overhead that
ideally is offset by improved memory locality but there is no universal
guarantee. If the target workload is already bound to NUMA nodes then this
-feature should be disabled. Otherwise, if the system overhead from the
-feature is too high then the rate the kernel samples for NUMA hinting
-faults may be controlled by the `numa_balancing_scan_period_min_ms,
-numa_balancing_scan_delay_ms, numa_balancing_scan_period_max_ms,
-numa_balancing_scan_size_mb`_, and numa_balancing_settle_count sysctls.
-
-
-numa_balancing_scan_period_min_ms, numa_balancing_scan_delay_ms, numa_balancing_scan_period_max_ms, numa_balancing_scan_size_mb
-===============================================================================================================================
-
-
-Automatic NUMA balancing scans tasks address space and unmaps pages to
-detect if pages are properly placed or if the data should be migrated to a
-memory node local to where the task is running. Every "scan delay" the task
-scans the next "scan size" number of pages in its address space. When the
-end of the address space is reached the scanner restarts from the beginning.
-
-In combination, the "scan delay" and "scan size" determine the scan rate.
-When "scan delay" decreases, the scan rate increases. The scan delay and
-hence the scan rate of every task is adaptive and depends on historical
-behaviour. If pages are properly placed then the scan delay increases,
-otherwise the scan delay decreases. The "scan size" is not adaptive but
-the higher the "scan size", the higher the scan rate.
-
-Higher scan rates incur higher system overhead as page faults must be
-trapped and potentially data must be migrated. However, the higher the scan
-rate, the more quickly a tasks memory is migrated to a local node if the
-workload pattern changes and minimises performance impact due to remote
-memory accesses. These sysctls control the thresholds for scan delays and
-the number of pages scanned.
-
-``numa_balancing_scan_period_min_ms`` is the minimum time in milliseconds to
-scan a tasks virtual memory. It effectively controls the maximum scanning
-rate for each task.
-
-``numa_balancing_scan_delay_ms`` is the starting "scan delay" used for a task
-when it initially forks.
-
-``numa_balancing_scan_period_max_ms`` is the maximum time in milliseconds to
-scan a tasks virtual memory. It effectively controls the minimum scanning
-rate for each task.
-
-``numa_balancing_scan_size_mb`` is how many megabytes worth of pages are
-scanned for a given scan.
-
+feature should be disabled.
oops_all_cpu_backtrace
======================