much higher filesystem I/O performance, and much better paging performance. It
represents the culmination of over 6 months of R&D.
The majority of the merged VM/cache work is by John Dyson.
The following highlights the most significant changes. Additionally, there are
(mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to
support the new VM/buffer scheme.
vfs_bio.c:
Significant rewrite of most of vfs_bio to support the merged VM buffer cache
scheme. The scheme is almost fully compatible with the old filesystem
interface. Significant improvement in the number of opportunities for write
clustering.
vfs_cluster.c, vfs_subr.c
Upgrade and performance enhancements in vfs layer code to support merged
VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff.
vm_object.c:
Yet more improvements in the collapse code. Elimination of some windows that
can cause list corruption.
vm_pageout.c:
Fixed it, it really works better now. Somehow in 2.0, some "enhancements"
broke the code. This code has been reworked from the ground-up.
vm_fault.c, vm_page.c, pmap.c, vm_object.c
Support for small-block filesystems with merged VM/buffer cache scheme.
pmap.c vm_map.c
Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of
kernel PTs.
vm_glue.c
Much simpler and more effective swapping code. No more gratuitous swapping.
proc.h
Fixed the problem that the p_lock flag was not being cleared on a fork.
swap_pager.c, vnode_pager.c
Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the
code doesn't need it anymore.
machdep.c
Changes to better support the parameter values for the merged VM/buffer cache
scheme.
machdep.c, kern_exec.c, vm_glue.c
Implemented a seperate submap for temporary exec string space and another one
to contain process upages. This eliminates all map fragmentation problems
that previously existed.
ffs_inode.c, ufs_inode.c, ufs_readwrite.c
Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on
busy buffers.
Submitted by: John Dyson and David Greenman
my mailbox since early last year. Fixes a problem with running out of
fds (by hitting the limit or whatever) when ar is given a long list of
objects. The fix was to add a missing close().
Submitted by: Robert Crowe <bob@speakez.com>
Reenabled "SCIOCOMAND" ioctl.
Restructured so low level drivers can easily request retries.
Added preliminary fixed SCSI devices (should be revisited before 2.1)
Added "ssc" device that can have its' (HBA, ID, LUN) set via ioctl.
shifting. Also correct the original code as Garrett noticed it in mail.
Leave the mishandled code in to use it later if future versions of gcc
are correct. The code was part of the calibrate_cyclecounter routine to
get the speed of the pentium chip.
floppy driver (or in the hardware?). It turned out to be caused by
spurious interrupts, right after an FDC reset.
Also major cleanup in the low-level structure, there are now functions
performing error-checks for the FDC I/O.
Submitted by: (mostly) Peter Dufault <dufault@FreeBSD.org>
It used to do this by setting a global <Yuck>. Now we set th VNINACT
flag in the vnode to force a skip of ufs_inactive.
Sorry for missing this file in my last commit folks.
Index: vnode.h
===================================================================
RCS file: /usr/cvs/src/sys/sys/vnode.h,v
retrieving revision 1.14
diff -c -r1.14 vnode.h
*** 1.14 1994/11/14 13:51:53
--- vnode.h 1994/12/03 01:06:27
***************
*** 116,121 ****
--- 116,122 ----
#define VALIASED 0x0800 /* vnode has an alias */
#define VDIROP 0x1000 /* LFS: vnode is involved in a directory op */
#define VVMIO 0x2000 /* VMIO flag */
+ #define VNINACT 0x4000 /* LFS: skip ufs_inactive() in lfs_vunref */
/*
* Vnode attributes. A field value of VNOVAL represents a field whose value
safe way to do this, and envites very unpleasant results. Removed fsck'ing
of all the disks on the system as it provides output that is almost always
meaningless and only envites bug reports.
Reviewed by: Jordan Hubbard
