dg bcc23094ea First round of changes from John Dyson and myself to the VM system. This ... set improves performance and fixes the following problems (description from John Dyson): 1. Growing swap space problem in both static usage and in situations with lots of fork/execs in heavy paging situations. 2. Sparse swap space allocation (internal fragmentation.) 3. General swap_pager slowness. Additionally, the new swap_pager also provides hooks for multi-page I/O that is currently being developed (in early testing phases.) Problem #1 is a result of a problem where objects cannot be collapsed once a pager has been allocated for them. This problem has been solved by relaxing the restriction by allowing the pages contained in a shadow object's pager be copied to the parent object's pager. The copy is afforded by manipulating pointers to the disk blocks on the swap space. Since an improved swap_pager has already been developed with the data structures to support the copy operation, this new swap_pager has been introduced. Also, shadow object bypass in the collapse code has been enhanced to support checking for pages on disk. The vm_pageout daemon has also been modified to defer creation of an object's pager when the object's shadow is paging. This allows efficient immediate collapsing of a shadow into a parent object under many circumstances without the creation of an intermediate pager. Problem #2 is solved by the allocation data structures and algorithms in the new swap_pager. Additionally, a newer version of this new swap_pager is being tested that permits multiple page I/O and mitigation of the fragmentation problems associated with allocation of large contiguous blocks of swap space. Problem #3 is addressed by better algorithms and a fix of a couple of bugs in the swap_pager. Additionally, this new pager has a growth path allowing multi-page inputs from disk. Approximately 50% performance improvement can be expected under certain circumstances when using this pager in the standard single page mode. (Actually, I've seen more like twice the speed in my tests. -DLG)		1993-12-22 12:51:39 +00:00
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alpha/include	Put back the $Id$ string	1993-10-28 06:11:38 +00:00
amd64	Changed pointer type from caddr_t to void * for fillw, insw, outsw, and	1993-12-21 21:27:04 +00:00
conf	Added support for X.25 as a network-layer protocol under ISO TP class 0, as	1993-12-19 22:45:13 +00:00
ddb	Make everything compile with -Wtraditional. Make it easier to distribute	1993-12-19 00:55:01 +00:00
dev	Use separate fields for format GAP and read/write GAP.	1993-12-21 05:09:21 +00:00
i386	Changed pointer type from caddr_t to void * for fillw, insw, outsw, and	1993-12-21 21:27:04 +00:00
isa	Use separate fields for format GAP and read/write GAP.	1993-12-21 05:09:21 +00:00
kern	First round of changes from John Dyson and myself to the VM system. This	1993-12-22 12:51:39 +00:00
powerpc/include	adding libc/quad:	1993-12-19 05:14:46 +00:00
scsi	Make everything compile with -Wtraditional. Make it easier to distribute	1993-12-19 00:55:01 +00:00
sys	Separate read/write and format GAPs.	1993-12-21 05:11:10 +00:00