git: kernel - Remove P_SWAPPEDOUT flag and paging mode
dillon at crater.dragonflybsd.org
Sat Jul 25 12:31:49 PDT 2020
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date: Fri Jul 24 22:57:11 2020 -0700
kernel - Remove P_SWAPPEDOUT flag and paging mode
* This code basically no longer functions in any worthwhile or
useful manner, remove it.
The code harkens back to a time when machines had very little
memory and had to time-share processes by actually descheduling
them for long periods of time (like 20 seconds) and paging out
the related memory.
In modern times the chooser algorithm just doesn't work well
because we can no longer assume that programs with large
memory footprints can be demoted.
* In modern times machines have sufficient memory to rely almost
entirely on the VM fault and pageout scan. The latencies caused
by fault-ins are usually sufficient to demote paging-intensive
processes while allowing the machine to continue to function.
If functionality need to be added back in, it can be added back
in on the fault path and not here.
Summary of changes:
sys/kern/tty.c | 2 +-
sys/platform/pc64/x86_64/trap.c | 16 --
sys/platform/vkernel64/x86_64/trap.c | 18 --
sys/sys/proc.h | 7 +-
sys/vfs/procfs/procfs_ctl.c | 1 -
sys/vfs/procfs/procfs_status.c | 5 +-
sys/vm/vm_extern.h | 1 -
sys/vm/vm_glue.c | 326 +----------------------------------
sys/vm/vm_meter.c | 19 +-
sys/vm/vm_pageout.c | 50 +-----
10 files changed, 22 insertions(+), 423 deletions(-)
DragonFly BSD source repository
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