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
Fix single-stepping of emulated FPU instructions.
Don't panic if an FPU instruction is attempted but there is no FPU
and no FPU emulator is configured.
short, it gets filled uop to its length. This matches the getdomainname
and gethostname manual pages.
(getbootfile also uses this function and I think it should have the same
behaviour)
This also fixes a bug with keyinit where the seed was not saved in
/etc/skeykeys. So S/Key should be fully functional again.
Reviewed by:
Submitted by:
Obtained from:
Improve hzto():
Round up instead of down and then add 1 tick. This fixes sleep(1)
sometimes sleeping for < 1 second and usleep(10000) sometimes sleeping
for as little as 1 usec + syscall time.
Don't do all the calculations at splhigh().
Don't depend on `tick' being a multiple of 1000.
Don't lose accuracy for `sec' between 0x7fffffff / 1000 - 1000 and
0x7fffffff / hz.
Don't assume that longs are 32 bits or that ints have the same size as
longs.
of returning EINVAL since something may depend on them being broken.
Allowing negative limits caused bugs almost everywhere. The recent
fixes for MAXSSIZ checked the limits too late to stop anyone defeating
limits set by root...
used as an address value. Then all comparisons should be done unsigned
and not signed. Fix it with a typecast of u_quad_t.
Error can be demonstrated with the current bash in port, do a
ulimit -s unlimited and the machine hangs. bash delivers through
an internal error a large negative value for the stacksize, the
comparison saw this smaller than MAXSSIZ and then tried to expand
the stack to this size.
operation of each clist. Limit the growth of each clist. Clists
can only grow larger than the reserved minimum if there are free
cblocks in a shared pool. The size of this pool is now fixed
(this could be improved). The reserved and maximum sizes are more
carefully allocated for slip and ppp, depending on the mtu. A maximum
MTU of 16384 is now enforced for ppp.
1. The pageout daemon used to block under certain
circumstances, and we needed to add new functionality
that would cause the pageout daemon to block more often.
Now, the pageout daemon mostly just gets rid of pages
and kills processes when the system is out of swap.
The swapping, rss limiting and object cache trimming
have been folded into a new daemon called "vmdaemon".
This new daemon does things that need to be done for
the VM system, but can block. For example, if the
vmdaemon blocks for memory, the pageout daemon
can take care of it. If the pageout daemon had
blocked for memory, it was difficult to handle
the situation correctly (and in some cases, was
impossible).
2. The collapse problem has now been entirely fixed.
It now appears to be impossible to accumulate unnecessary
vm objects. The object collapsing now occurs when ref counts
drop to one (where it is more likely to be more simple anyway
because less pages would be out on disk.) The original
fixes were incomplete in that pathological circumstances
could still be contrived to cause uncontrolled growth
of swap. Also, the old code still, under steady state
conditions, used more swap space than necessary. When
using the new code, users will generally notice a
significant decrease in swap space usage, and theoretically,
the system should be leaving fewer unused pages around
competing for memory.
Submitted by: John Dyson
Find enclosed a short bugfix to get the union filesystem up and running
in FreeBSD-current. We don't think we've got all the problems yet but
these fixes sort out the major ones (which mostly concert bad locking
of vnodes), no doubt we'll post others as necessary. Known problems
include the inability of the umount command (not the system call) to unmount
unions in certain circumstances (this is due the way "realpath" works),
and the failure of direntries to always get all available files in
unioned subdirectories. We are, as they say, working on it.
Submitted by: tim@cs.city.ac.uk (Tim Wilkinson)
a clist return with an error. There are some clist starvation/deadlock
bugs elsewhere and killing clist hogs didn't help because the breaks
only exited from the inner loops.
Cosmetic.
Return from trap() if trap_fatal() returns. trap_fatal() isn't
fatal if you have ddb. Returning from trap() is usually the right
thing to do and much better than falling through.
and all SCSI devices (except that it's not done quite the way I want). New
information added includes:
- A text description of the device
- A ``state''---unknown, unconfigured, idle, or busy
- A generic parent device (with support in the m.i. code)
- An interrupt mask type field (which will hopefully go away) so that
. ``doconfig'' can be written
This requires a new version of the `lsdev' program as well (next commit).
A word of wisdom, don't do this:
| cd /usr/bin
| for i in *
| do
| cp $i /tmp/a
| gzip -9 < /tmp/a > $i
| done
It will compress files with multiple links several times. do it this way:
| cd /usr/bin
| for i in *
| do
| gunzip -f < $i > /tmp/a
| gzip -9 < /tmp/a > $i
| done
For it to be useful, you must stick your disklabel on the partition which
starts where the MBR says FreeBSD lives. If you don't do that, you might
get a bad day.
Oh, that probably also means that putting swap there is a bad idea...
- excise some unused code (#if 0'd out - don't want to nuke it yet)
- fix problems with "make depend" - some macros were screwing it up
- get rid of some static local variables
There still seems to be a small reentrancy problem somewhere.
pmap.c: tons of unused vars zapped, various other warnings silenced.
trap.c: unused vars zapped.
vm_machdep.c: A wrong argument, which by chance did the right thing, was
corrected.
1) cut this up into /sys/sys/inflate.h, sys/kern/inflate.c
sys/kern/ingact_gzip.c
2) make a lot more things static
3) make a lot of globals const
4) make some args const
5) first stage of making globals into a struct (not used yet)
The vm_allocate() call which was introduced between revisions 1.4 and
1.5 of imagact_gzip.c broke things. I have backed that out for the time
being. (Davidg: help please)
WARNING: if you have gzip enabled in your kernel, you must now run
config again, as another source file has been added. Otherwise your
kernel compile will fall over.
This is all still WIP. More commits to come.
Suggestions from: phk.
more weird kinds of a.out than anyone can argue for. This code failed to
load the first 28K of the text-segment, in the case where the first page
of the a.out contains only the a.out-header, and the text is still at 0x0.
Thanks Steven !
the uncompression buffer. Now malloc(M_GZIP) is used for all the Huffman-
tree stuff only. Numbers so far indicate < 15Kb Malloc use + 32 Kb for
the abovementioned buffer while uncompressing.
cleaned up much of the cruft in this thing.
No printf's in the case where things go well.
Gzip-headers can contain filenames and comments (as long as they're
shorter than the page-size.)
I don't think we leak memory, in the "exec/aout" code. I'm not quite sure
about the inflate code yet, but I don't think memory is lost.
Q: Can I add a class M_GZIP to <sys/malloc.h> and bump M_LAST one up
without any thing else needing tweaking ?
Poul-Henning
WARNING: THIS MATERIAL MIGHT GO AWAY!
This material needs the core-groups approval to stay here for the 2.0 release.
If the core-group does not concent to this commit, it will be backed out.
***
It is a non-gpl'ed "unzip" which will allow execution of a.out files which
have been sent through "gzip -9". The idea being saved disk-space.
Just now this code has quality rating: "working prototype".
To compress a file to be used with this, do it exactly this way:
gzip -9 -v < /bin/FOO > /tmp/FOO
remember to chmod /tmp/FOO as needed.
DON'T compress all of you binaries right away ! There are several things
which you should consider first:
1. Using compressed binaries, you use >MUCH< more VM, and thus swap-space.
2. It is slow.
3. It might crash your machine.
Apart from that, I welcome comments...
NB: There is also a change to sys/conf/files, but cvs core-dumped on me,
so it didn't get into the logs or emailed, but the commit seems to have
happended OK.
cycles. While waiting there I added a lot of the extra ()'s I have, (I have
never used LISP to any extent). So I compiled the kernel with -Wall and
shut up a lot of "suggest you add ()'s", removed a bunch of unused var's
and added a couple of declarations here and there. Having a lap-top is
highly recommended. My kernel still runs, yell at me if you kernel breaks.
- Make a number of filesystems work again when they are statically compiled
(blush)
- FIFOs are no longer optional; ``options FIFO'' removed from distributed
config files.
- set args->lkm_offset correctly so that VFS modules can be unloaded
- initialize _fs_vfsops.vfc_refcount correctly so that VFS modules can
be unloaded
- include kernel.h in a few placves to get the correct definition of DATA_SET
This code is mostly taken from the 1.1 port (which was in turn taken from
Dave Mills's kern.tar.Z example). A few significant differences:
1) ntp_gettime() is now a MIB variable rather than a system call. A few
fiddles are done in libc to make it behave the same.
2) mono_time does not participate in the PLL adjustments.
3) A new interface has been defined (in <machine/clock.h>) for doing
possibly machine-dependent things around the time of the clock update.
This is used in Pentium kernels to disable interrupts, set `time', and
reset the CPU cycle counter as quickly as possible to avoid jitter in
microtime(). Measurements show an apparent resolution of a bit more than
8.14usec, which is reasonable given system-call overhead.
otherwise the machine will overflow the stack in a recursive fault loop
(causing the machine to spontaneously reboot because of the stack fault
that ultimately happens).
Submitted by: Inspired by Bruce Evans, but this change is different
than what he suggested.
the Mach/i386 version of the BSD/vax(?) <machine/psl.h>. The Mach
version has slightly better names for many macros but is now out of
date and little used. It was originally used even less (for spelling
PSL_T as EFL_TF in <machine/db_machdep.h>).
Added "sys/rtprio.h" with the used defines.
Added rtprio(2) - the kernel interface. init_sysent.c,
kern_resource.c
syscalls.master
Added 32 new runqueues (rtqs), with initialization. kern_proc.c
kern_synch.c
Realtime processes do not change nice/priority kern_synch.c
Added a column "rt" to ddb's ps (#ifdef RTPRIO_DEBUG) kern_synch.c
Realtime priorities are enherited through fork(). kern_fork.c
Init (and children) NOT run as realtime process. init_main.c
Submitted by: Henrik Vestergaard Draboel
with BOUNCE_BUFFERS. This is more intuitive, and is better for future
multiplatform support. Added BOUNCE_BUFFERS option to the GENERIC and
LINT kernel config files.
com.h/lpa.h. Removed all vestiges of com/lpa out of conf.c and also
fixed up the end of cdevsw/bdevsw to have "no" routines instead of
a NULL pointer (suggested by someone a few weeks back).
in your kernel config now).
2) Added ps ddb function from 1.1.5. Cleaned it up a bit and moved into its
own file.
3) Added \r handing in db_printf.
4) Added missing memory usage stats to statclock().
5) Added dummy function to pseudo_set so it will be emitted if there
are no other pseudo declarations.
machdep.c:
Changed printf's a little and call vfs_unmountall() if the sync was
successful.
cd9660_vfsops.c, ffs_vfsops.c, nfs_vfsops.c, lfs_vfsops.c:
Allow dismount of root FS. It is now disallowed at a higher level.
vfs_conf.c:
Removed unused rootfs global.
vfs_subr.c:
Added new routines vfs_unmountall and vfs_unmountroot. Filesystems
are now dismounted if the machine is properly rebooted.
ffs_vfsops.c:
Toggle clean bit at the appropriate places. Print warning if an
unclean FS is mounted.
ffs_vfsops.c, lfs_vfsops.c:
Fix bug in selecting proper flags for VOP_CLOSE().
vfs_syscalls.c:
Disallow dismounting root FS via umount syscall.
use of timeout_t -> timeout_func_t in aha1542 and aha1742 drivers.
2) fix a bug in the portalfs that was uncovered by better prototyping -
specifically, the time must be converted from timeval to timespec
before storing in va_atime.
3) fixed/added some miscellaneous prototypes
- Delete redundant declarations.
- Add -Wredundant-declarations to Makefile.i386 so they don't come back.
- Delete sloppy COMMON-style declarations of uninitialized data in
header files.
- Add a few prototypes.
- Clean up warnings resulting from the above.
NB: ioconf.c will still generate a redundant-declaration warning, which
is unavoidable unless somebody volunteers to make `config' smarter.
done. This patch was extended to also include a suggested change by
Kirk McKusick which allows the control tty to be reasigned to a different
tty without losing a vnode.
``changes'' are actually not changes at all, but CVS sometimes has trouble
telling the difference.
This also includes support for second-directory compiles. This is not
quite complete yet, as `config' doesn't yet do the right thing. You can
still make it work trivially, however, by doing the following:
rm /sys/compile
mkdir /usr/obj/sys/compile
ln -s M-. /sys/compile
cd /sys/i386/conf
config MYKERNEL
cd ../../compile/MYKERNEL
ln -s /sys @
rm machine
ln -s @/i386/include machine
make depend
make
are running under. Here's how to bootstrap (order is important):
1) Re-compile gcc (just the driver is all you need).
2) Re-compile libc.
3) Re-compile your kernel. Reboot.
4) cd /usr/src/include; make install
You can now detect the compilation environment with the following code:
#if !defined(__FreeBSD__)
#define __FreeBSD_version 199401
#elif __FreeBSD__ == 1
#define __FreeBSD_version 199405
#else
#include <osreldate.h>
#endif
You can determine the run-time environment by calling the new C library
function getosreldate(), or by examining the MIB variable kern.osreldate.
For the time being, the release date is defined as 199409, which we have
already established as our target.
use it in NFS. This is required both for diskless support and for POSIX
compliance. Note: the support in NFS is only for the local node.
Submitted by: based on work originally done by Yuval Yurom
improvements via the new routines pmap_qenter/pmap_qremove and pmap_kenter/
pmap_kremove. These routine allow fast mapping of pages for those
architectures that have "normal" MMUs. Also included is a fix to the
pageout daemon to properly check a queue end condition.
Submitted by: John Dyson
charge scheduling CPU of child process to the parent and have child
inherit scheduling CPU from parent on fork. Makes a **big** difference
in the feel of the system to interactive users.
Submitted by: John Dyson
Imported libmd. This library contains MD2, MD4 and MD5.
These three boggers pop up all over the place all of the time, so I
decided we needed a library with them. In general they are used for
security checks, so if you use them you want to link them static.
a tty.
Note that this might conflict with the collateral use of TS_WOPEN, but
for the moment I can find no problems associated with this. (TS_WOPEN
will likely go away in the future anyway). This should be looked at
again in the future (the potential problem is that the cblock pool
may either run out or accumulate too many cblocks).
Vastly improved trap.c from me. This rewritten version has a variety of
features, amoung them: higher performance and much higher code quality.
support.s, cpufunc.h:
No longer use gs override to enforce range limits - compare directly
against VM_MAXUSER_ADDRESS instead. The old way caused problems in
preserving the gs selector...and this method is just as fast or faster.
list of changes, I've made the following additional changes:
1) i386/include/ipl.h renamed to spl.h as the name conflicts with the
file of the same name in i386/isa/ipl.h.
2) changed all use of *mask (i.e. netmask, biomask, ttymask, etc) to
*_imask (net_imask, etc).
3) changed vestige of splnet use in if_is to splimp.
4) got rid of "impmask" completely (Bruce had gotten rid of netmask),
and are now using net_imask instead.
5) dozens of minor cruft to glue in Bruce's changes.
These require changes I made to config(8) as well, and thus it must
be rebuilt.
-DG
from Bruce Evans:
sio:
o No diff is supplied. Remove the define of setsofttty(). I hope
that is enough.
*.s:
o i386/isa/debug.h no longer exists. The event counters became too
much trouble to maintain. All function call entry and exception
entry counters can be recovered by using profiling kernel (the new
profiling supports all entry points; however, it is too slow to
leave enabled all the time; it also). Only BDBTRAP() from debug.h
is now used. That is moved to exception.s. It might be worth
preserving SHOW_BITS() and calling it from _mcount() (if enabled).
o T_ASTFLT is now only set just before calling trap().
o All exception handlers set SWI_AST_MASK in cpl as soon as possible
after entry and arrange for _doreti to restore it atomically with
exiting. It is not possible to set it atomically with entering
the kernel, so it must be checked against the user mode bits in
the trap frame before committing to using it. There is no place
to store the old value of cpl for syscalls or traps, so there are
some complications restoring it.
Profiling stuff (mostly in *.s):
o Changes to kern/subr_mcount.c, gcc and gprof are not supplied yet.
o All interesting labels `foo' are renamed `_foo' and all
uninteresting labels `_bar' are renamed `bar'. A small change
to gprof allows ignoring labels not starting with underscores.
o MCOUNT_LABEL() is to provide names for counters for times spent
in exception handlers.
o FAKE_MCOUNT() is a version of MCOUNT() suitable for exception
handlers. Its arg is the pc where the exception occurred. The
new mcount() pretends that this was a call from that pc to a
suitable MCOUNT_LABEL().
o MEXITCOUNT is to turn off any timer started by MCOUNT().
/usr/src/sys/i386/i386/exception.s:
o The non-BDB BPTTRAP() macros were doing a sti even when interrupts
were disabled when the trap occurred. The sti (fixed) sti is
actually a no-op unless you have my changes to machdep.c that make
the debugger trap gates interrupt gates, but fixing that would
make the ifdefs messier. ddb seems to be unharmed by both
interrupts always disabled and always enabled (I had the branch in
the fix back to front for some time :-().
o There is no known pushal bug.
o tf_err can be left as garbage for syscalls.
/usr/src/sys/i386/i386/locore.s:
o Fix and update BDE_DEBUGGER support.
o ENTRY(btext) before initialization was dangerous.
o Warm boot shot was longer than intended.
/usr/src/sys/i386/i386/machdep.c:
o DON'T APPLY ALL OF THIS DIFF. It's what I'm using, but may require
other changes.
Use the following:
o Remove aston() and setsoftclock().
Maybe use the following:
o No netisr.h.
o Spelling fix.
o Delay to read the Rebooting message.
o Fix for vm system unmapping a reduced area of memory
after bounds_check_with_label() reduces the size of
a physical i/o for a partition boundary. A similar
fix is required in kern_physio.c.
o Correct use of __CONCAT. It never worked here for non-
ANSI cpp's. Is it time to drop support for non-ANSI?
o gdt_segs init. 0xffffffffUL is bogus because ssd_limit
is not 32 bits. The replacement may have the same
value :-), but is more natural.
o physmem was one page too low. Confusing variable names.
Don't use the following:
o Better numbers of buffers. Each 8K page requires up to
16 buffer headers. On my system, this results in 5576
buffers containing [up to] 2854912 bytes of memory.
The usual allocation of about 384 buffers only holds
192K of disk if you use it on an fs with a block size
of 512.
o gdt changes for bdb.
o *TGT -> *IDT changes for bdb.
o #ifdefed changes for bdb.
/usr/src/sys/i386/i386/microtime.s:
o Use the correct asm macros. I think asm.h was copied from Mach
just for microtime and isn't used now. It certainly doesn't
belong in <sys>. Various macros are also duplicated in
sys/i386/boot.h and libc/i386/*.h.
o Don't switch to and from the IRR; it is guaranteed to be selected
(default after ICU init and explicitly selected in isa.c too, and
never changed until the old microtime clobbered it).
/usr/src/sys/i386/i386/support.s:
o Non-essential changes (none related to spls or profiling).
o Removed slow loads of %gs again. The LDT support may require
not relying on %gs, but loading it is not the way to fix it!
Some places (copyin ...) forgot to load it. Loading it clobbers
the user %gs. trap() still loads it after certain types of
faults so that fuword() etc can rely on it without loading it
explicitly. Exception handlers don't restore it. If we want
to preserve the user %gs, then the fastest method is to not
touch it except for context switches. Comparing with
VM_MAXUSER_ADDRESS and branching takes only 2 or 4 cycles on
a 486, while loading %gs takes 9 cycles and using it takes
another.
o Fixed a signed branch to unsigned.
/usr/src/sys/i386/i386/swtch.s:
o Move spl0() outside of idle loop.
o Remove cli/sti from idle loop. sw1 does a cli, and in the
unlikely event of an interrupt occurring and whichqs becoming
zero, sw1 will just jump back to _idle.
o There's no spl0() function in asm any more, so use splz().
o swtch() doesn't need to be superaligned, at least with the
new mcounting.
o Fixed a signed branch to unsigned.
o Removed astoff().
/usr/src/sys/i386/i386/trap.c:
o The decentralized extern decls were inconsistent, of course.
o Fixed typo MATH_EMULTATE in comments. */
o Removed unused variables.
o Old netmask is now impmask; print it instead. Perhaps we
should print some of the new masks.
o BTW, trap() should not print anything for normal debugger
traps.
/usr/src/sys/i386/include/asmacros.h:
o DON'T APPLY ALL OF THIS DIFF. Just use some of the null macros
as necessary.
/usr/src/sys/i386/include/cpu.h:
o CLKF_BASEPRI() changes since cpl == SWI_AST_MASK is now normal
while the kernel is running.
o Don't use var++ to set boolean variables. It fails after a mere
4G times :-) and is slower than storing a constant on [3-4]86s.
/usr/src/sys/i386/include/cpufunc.h:
o DON'T APPLY ALL OF THIS DIFF. You need mainly the include of
<machine/ipl.h>. Unfortunately, <machine/ipl.h> is needed by
almost everything for the inlines.
/usr/src/sys/i386/include/ipl.h:
o New file. Defines spl inlines and SWI macros and declares most
variables related to hard and soft interrupt masks.
/usr/src/sys/i386/isa/icu.h:
o Moved definitions to <machine/ipl.h>
/usr/src/sys/i386/isa/icu.s:
o Software interrupts (SWIs) and delayed hardware interrupts (HWIs)
are now handled uniformally, and dispatching them from splx() is
more like dispatching them from _doreti. The dispatcher is
essentially *(handler[ffs(ipending & ~cpl)]().
o More care (not quite enough) is taken to avoid unbounded nesting
of interrupts.
o The interface to softclock() is changed so that a trap frame is
not required.
o Fast interrupt handlers are now handled more uniformally.
Configuration is still too early (new handlers would require
bits in <machine/ipl.h> and functions to vector.s).
o splnnn() and splx() are no longer here; they are inline functions
(could be macros for other compilers). splz() is the nontrivial
part of the old splx().
/usr/src/sys/i386/isa/ipl.h
o New file. Supposed to have only bus-dependent stuff. Perhaps
the h/w masks should be declared here.
/usr/src/sys/i386/isa/isa.c:
o DON'T APPLY ALL OF THIS DIFF. You need only things involving
*mask and *MASK and comments about them. netmask is now a pure
software mask. It works like the softclock mask.
/usr/src/sys/i386/isa/vector.s:
o Reorganize AUTO_EOI* macros.
o Option FAST_INTR_HANDLER_USERS_ES for people who don't trust
fastintr handlers.
o fastintr handlers need to metamorphose into ordinary interrupt
handlers if their SWI bit has become set. Previously, sio had
unintended latency for handling output completions and input
of SLIP framing characters because this was not done.
/usr/src/sys/net/netisr.h:
o The machine-dependent stuff is now imported from <machine/ipl.h>.
/usr/src/sys/sys/systm.h
o DON'T APPLY ALL OF THIS DIFF. You need mainly the different
splx() prototype. The spl*() prototypes are duplicated as
inlines in <machine/ipl.h> but they need to be duplicated here
in case there are no inlines. I sent systm.h and cpufunc.h
to Garrett. We agree that spl0 should be replaced by splnone
and not the other way around like I've done.
/usr/src/sys/kern/kern_clock.c
o splsoftclock() now lowers cpl so the direct call to softclock()
works as intended.
o softclock() interface changed to avoid passing the whole frame
(some machines may need another change for profile_tick()).
o profiling renamed _profiling to avoid ANSI namespace pollution.
(I had to improve the mcount() interface and may as well fix it.)
The GUPROF variant doesn't actually reference profiling here,
but the 'U' in GUPROF should mean to select the microtimer
mcount() and not change the interface.
1) A new mechanism has been added to prevent pages from being paged
out called "vm_page_hold". Similar to vm_page_wire, but
much lower overhead.
2) Scheduling algorithm has been changed to improve interactive
performance.
3) Paging algorithm improved.
4) Some vnode and swap pager bugs fixed.
Eliminates vm_fault overhead on process startup and
mmap referenced data for in-memory pages.
(process startup time using in-memory segments *much* faster)
2) Even more efficient pmap code. Code partially cleaned up.
More comments yet to follow.
(generally more efficient pte management)
3) Pageout clustering ( in addition to the FreeBSD V1.1 pagein
clustering.)
(much faster paging performance on non-write behind disk
subsystems, slightly faster performance on other systems.)
4) Slightly changed vm_pageout code for more efficiency and
better statistics. Also, resist swapout a little more.
(less likely to pageout a recently used page)
5) Slight improvement to the page table page trap efficiency.
(generally faster system VM fault performance)
6) Defer creation of unnamed anonymous regions pager until needed.
(speeds up shared memory bss creation)
7) Remove possible deadlock from swap_pager initialization.
8) Enhanced procfs to provide "vminfo" about vm objects and user
pmaps.
9) Increased MCLSHIFT/MCLBYTES from 2K to 4K to improve net &
socket performance and to prepare for things to come.
John Dyson
dyson@implode.root.com
David Greenman
davidg@root.com
the device close routine. This works because the device close calls
the line discipline close (which only flushes the output buffers) and
the ttyclose() routine, which does little of nothing except screw with
the session and process group fields (which is what was causing all
the problems).
* Removed pmap_is_wired
* added extra cli/sti protection in idle (swtch.s)
* slight code improvement in trap.c
* added lots of comments
* improved paging and other algorithms in VM system
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)
a binary link-kit. Make all non-optional options (pagers, procfs) standard,
and update LINT to reflect new symtab requirements.
NB: -Wtraditional will henceforth be forgotten. This editing pass was
primarily intended to detect any constructions where the old code might
have been relying on traditional C semantics or syntax. These were all
fixed, and the result of fixing some of them means that -Wall is now a
realistic possibility within a few weeks.
John Dyson to make it reliably work under FreeBSD.
2) Added and enabled PROCFS in the GENERICxx and LINT kernels.
3) New execve() from me. Still work to be done here, but this version
works well and is needed before other changes can be made. For
a description of the design behind this, see freebsd-arch or
ask me.
4) Rewrote stack fault code; made user stack VM grow as needed rather
than all up front; improves performance a little and reduces
process memory requirements.
5) Incorporated fix from Gene Stark to fault/wire a user page table
page to fix a problem in copyout. This is a temporary fix and
is not appropriate for pageable page tables. For a description
of the problem, see Gene's post to the freebsd-hackers mailing
list.
6) Tighten up vm_page struct to reduce memory requirements for it. ifdef
pager page lock code as it's not being used currently.
7) Introduced new element to vmspace struct - vm_minsaddr; initial
(minimum) stack address. Compliment to vm_maxsaddr.
8) Added a panic if the allocation for process u-pages fails.
9) Improve performance and accuracy of kernel profiling by putting in
a little inline assembly instead of spl().
10) Made serial console with sio driver work. Still has problems with
serial input, but is almost useable.
11) Added -Bstatic to SYSTEM_LD in Makefile.i386 so that kernels will
build properly with the new ld.
The following patch adds the addr argument to signal handlers.
The kernel with the patch is no more and no less in compliance or in
violation of POSIX and ANSI C than the kernel before the patch.
The added functionality this addr argument provides is quite useful. It
enables an entire class of algorithms which use mprotect to trace memory
references. Beside garbage collectors, I have heard of this technique being
applied to debuggers and profilers. The only benchmarking I've performed is
using akcl to compile maxima: without the kernel patch, it takes 7 hours to
compile maxima, while with stratified garbage collection, it only takes 50
minutes.
Basically, I can't think of a reason not to add the addr argument and there
is a compelling need for it.
If you find the patch acceptable, please let me know so I can send my
FreeBSD akcl config files to wfs for inclusion in the core akcl release.
The old 386BSD config files there won't work on either NetBSD or FreeBSD.
Subject: Page fault in PTE area fails in copyout
Index: sys/i386/i386/trap.c FreeBSD-1.0.2
Description:
Reading files of several megabytes into Emacs, or many small
files all at once, would fail with "IO error - bad address".
Repeat-By:
The bug can be exercised by a test program that malloc()'s
a 5MB chunk of memory, and then, without accessing the memory
first, filling it with data from a file using read().
(I read 64k chunks from /dev/wd0d into successive 64k regions
of the 5MB chunk.) The read() will fail with EFAULT at the first
virtual address boundary that is a multiple of 0x400000.
Fix:
The problem was code in sys/i386/i386/trap.c that tries to
figure out what kind of trap occurred and to handle it appropriately.
It was interpreting any page fault with virtual address
>= vm->vm_maxsaddr as being a user stack segment fault.
In fact, addresses >= USRSTACK are in the user structure/PTE area,
and if they are handled as stack faults, the proper PTE will
not be paged in when it is supposed to be. This situation comes
up in copyout() and copyoutstr(), if PTE's are accessed for the
first time ever. The page fault on accessing the nonexistent PTE
is mishandled as a stack fault, and then the fault that occurs on
the subsequent access to the page itself causes copyout to fail
with EFAULT.
when the machine panics.
i386/i386/locore.s:
1) got rid of most .set directives that were being used like
#define's, and replaced them with appropriate #define's in
the appropriate header files (accessed via genassym).
2) added comments to header inclusions and global definitions,
and global variables
3) replaced some hardcoded constants with cpp defines (such as
PDESIZE and others)
4) aligned all comments to the same column to make them easier to
read
5) moved macro definitions for ENTRY, ALIGN, NOP, etc. to
/sys/i386/include/asmacros.h
6) added #ifdef BDE_DEBUGGER around all of Bruce's debugger code
7) added new global '_KERNend' to store last location+1 of kernel
8) cleaned up zeroing of bss so that only bss is zeroed
9) fix zeroing of page tables so that it really does zero them all
- not just if they follow the bss.
10) rewrote page table initialization code so that 1) works correctly
and 2) write protects the kernel text by default
11) properly initialize the kernel page directory, upages, p0stack PT,
and page tables. The previous scheme was more than a bit
screwy.
12) change allocation of virtual area of IO hole so that it is
fixed at KERNBASE + 0xa0000. The previous scheme put it
right after the kernel page tables and then later expected
it to be at KERNBASE +0xa0000
13) change multiple bogus settings of user read/write of various
areas of kernel VM - including the IO hole; we should never
be accessing the IO hole in user mode through the kernel
page tables
14) split kernel support routines such as bcopy, bzero, copyin,
copyout, etc. into a seperate file 'support.s'
15) split swtch and related routines into a seperate 'swtch.s'
16) split routines related to traps, syscalls, and interrupts
into a seperate file 'exception.s'
17) remove some unused global variables from locore that got
inserted by Garrett when he pulled them out of some .h
files.
i386/isa/icu.s:
1) clean up global variable declarations
2) move in declaration of astpending and netisr
i386/i386/pmap.c:
1) fix calculation of virtual_avail. It previously was calculated
to be right in the middle of the kernel page tables - not
a good place to start allocating kernel VM.
2) properly allocate kernel page dir/tables etc out of kernel map
- previously only took out 2 pages.
i386/i386/machdep.c:
1) modify boot() to print a warning that the system will reboot in
PANIC_REBOOT_WAIT_TIME amount of seconds, and let the user
abort with a key on the console. The machine will wait for
ever if a key is typed before the reboot. The default is
15 seconds, but can be set to 0 to mean don't wait at all,
-1 to mean wait forever, or any positive value to wait for
that many seconds.
2) print "Rebooting..." just before doing it.
kern/subr_prf.c:
1) remove PANICWAIT as it is deprecated by the change to machdep.c
i386/i386/trap.c:
1) add table of trap type strings and use it to print a real trap/
panic message rather than just a number. Lot's of work to
be done here, but this is the first step. Symbolic traceback
is in the TODO.
i386/i386/Makefile.i386:
1) add support in to build support.s, exception.s and swtch.s
...and various changes to various header files to make all of the
above happen.
the stack area and not memory above VM_MAXUSER_ADDRESS.
That way, copyout and friends now work for pages whose page table entries
have not yet been allocated/been paged out.
Remove NKMEMCLUSTERS, it is no longer define or used.
locores.s:
Fix comment on PTDpde and APTDpde to be pde instead of pte
Add new equation for calculating location of Sysmap
Remove Bill's old #ifdef garbage for counting up memory,
that stuff will never be made to work and was just cluttering
up the file.
Add code that places the PTD, page table pages, and kernel
stack below the 640k ISA hole if there is room for it, otherwise
put this stuff all at 1MB. This fixes the 28K bogusity in
the boot blocks, that can now go away!
Fix the caclulation of where first is to be dependent on
NKPDE so that we can skip over the above mentioned areas.
The 28K thing is now 44K in size due to the increase in
kernel virtual memory space, but since we no longer have
to worry about that this is no big deal.
Use if NNPX > 0 instead of ifdef NPX for floating point code.
machdep.c
Change the calculation of for the buffer cache to be
20% of all memory above 2MB and add back the upper limit
of 2/5's of the VM_KMEM_SIZE so that we do not eat ALL
of the kernel memory space on large memory machines, note
that this will not even come into effect unless you have
more than 32MB. The current buffer cache limit is 6.7MB
due to this caclulation.
It seems that we where erroniously allocating bufpages pages
for buffer_map. buffer_map is UNUSED in this implementation
of the buffer cache, but since the map is referenced in
several if statements a quick fix was to simply allocate
1 vm page (but no real memory) to it.
pmap.h
Remove rcsid, don't want them in the kernel files!
Removed some cruft inside an #ifdef DEBUGx that caused
compiler errors if you where compiling this for debug.
Use the #defines for PD_SHIFT and PG_SHIFT in place of
constants.
trap.c:
Remove patch kit header and rcsid, fix $Id$.
Now include "npx.h" and use NNPX for controlling the
floating point code.
Remove a now completly invalid check for a maximum virtual
address, the virtual address now ends at 0xFFFFFFFF so
there is no more MAX!! (Thanks David, I completly missed
that one!)
vm_machdep.c
Remove patch kit header and rcsid, fix $Id$.
Now include "npx.h" and use NNPX for controlling the
floating point code.
Replace several 0xFE00000 constants with KERNBASE
FP and we try to call the emulator when it is not compiled in.
Removed the #if defined(i486) || defined(i387) that use to call the
panic if we did not have a math emulator.
Removed an extranious include of i386/i386/math_emu.h from math_emulate.c.
profiling, and various protection checks that cause security holes
and system crashes.
* Changed min/max/bcmp/ffs/strlen to be static inline functions
- included from cpufunc.h in via systm.h. This change
improves performance in many parts of the kernel - up to 5% in the
networking layer alone. Note that this requires systm.h to be included
in any file that uses these functions otherwise it won't be able to
find them during the load.
* Fixed incorrect call to splx() in if_is.c
* Fixed bogus variable assignment to splx() in if_ed.c
