kernel-hacking-2024-linux-s.../kernel/sched
Rik van Riel de1c9ce6f0 sched/numa: Skip some page migrations after a shared fault
Shared faults can lead to lots of unnecessary page migrations,
slowing down the system, and causing private faults to hit the
per-pgdat migration ratelimit.

This patch adds sysctl numa_balancing_migrate_deferred, which specifies
how many shared page migrations to skip unconditionally, after each page
migration that is skipped because it is a shared fault.

This reduces the number of page migrations back and forth in
shared fault situations. It also gives a strong preference to
the tasks that are already running where most of the memory is,
and to moving the other tasks to near the memory.

Testing this with a much higher scan rate than the default
still seems to result in fewer page migrations than before.

Memory seems to be somewhat better consolidated than previously,
with multi-instance specjbb runs on a 4 node system.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-62-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:48:21 +02:00
..
auto_group.c
auto_group.h
clock.c
core.c mm: numa: Revert temporarily disabling of NUMA migration 2013-10-09 14:48:20 +02:00
cpuacct.c cgroup: pass around cgroup_subsys_state instead of cgroup in file methods 2013-08-08 20:11:24 -04:00
cpuacct.h
cpupri.c sched: Fix some kernel-doc warnings 2013-07-18 09:58:21 +02:00
cpupri.h
cputime.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-09-05 12:36:46 -07:00
debug.c sched/numa: Add debugging 2013-10-09 14:48:04 +02:00
fair.c sched/numa: Skip some page migrations after a shared fault 2013-10-09 14:48:21 +02:00
features.h sched/numa: Resist moving tasks towards nodes with fewer hinting faults 2013-10-09 12:40:27 +02:00
idle_task.c sched/numa: Introduce migrate_swap() 2013-10-09 12:40:46 +02:00
Makefile
proc.c
rt.c sched/numa: Introduce migrate_swap() 2013-10-09 12:40:46 +02:00
sched.h sched/numa: Avoid migrating tasks that are placed on their preferred node 2013-10-09 14:48:10 +02:00
stats.c
stats.h sched: Micro-optimize by dropping unnecessary task_rq() calls 2013-09-25 13:51:06 +02:00
stop_task.c sched/numa: Introduce migrate_swap() 2013-10-09 12:40:46 +02:00