freebsd-skq/sys/i386
Alan Cox 87ee6303e5 Prior to r254304, we only began scanning the active page queue when the
amount of free memory was close to the point at which we would begin
reclaiming pages.  Now, we continuously scan the active page queue,
regardless of the amount of free memory.  Consequently, we are continuously
calling pmap_ts_referenced() on active pages.

Prior to this change, pmap_ts_referenced() would always demote superpage
mappings in order to obtain finer-grained reference information.  This made
sense because we were coming under memory pressure and would soon have to
begin reclaiming pages.  Now, however, with continuous scanning of the
active page queue, these demotions are taking a toll on performance.  To
address this problem, I have replaced the demotion with a heuristic for
periodically clearing the reference flag on superpage mappings.

Approved by:	re (kib)
Sponsored by:	EMC / Isilon Storage Division
2013-09-11 17:23:42 +00:00
..
acpica Consistently use round_page(x) rather than roundup(x, PAGE_SIZE). There is 2013-02-15 22:43:08 +00:00
bios This isn't functionally identical. In some cases a hint to disable 2012-10-22 13:06:09 +00:00
conf Add vmx device to the i386 and amd64 NOTES files 2013-09-06 20:24:21 +00:00
i386 Prior to r254304, we only began scanning the active page queue when the 2013-09-11 17:23:42 +00:00
ibcs2 Add a mmap flag (MAP_32BIT) on 64-bit platforms to request that a mapping use 2013-09-09 18:11:59 +00:00
include Implement PV IPIs for PVHVM guests and further converge PV and HVM 2013-09-06 22:17:02 +00:00
isa Implement vector callback for PVHVM and unify event channel implementations 2013-08-29 19:52:18 +00:00
linux Add a mmap flag (MAP_32BIT) on 64-bit platforms to request that a mapping use 2013-09-09 18:11:59 +00:00
pci Replace kernel virtual address space allocation with vmem. This provides 2013-08-07 06:21:20 +00:00
svr4
xbox Move the legacy(4) driver to x86. 2012-03-30 19:10:14 +00:00
xen Implement PV IPIs for PVHVM guests and further converge PV and HVM 2013-09-06 22:17:02 +00:00
Makefile Delete duplicate tags entry I introduced in -r223901. 2011-07-15 17:27:26 +00:00