Commit Graph

272 Commits

Author SHA1 Message Date
Bosko Milekic
9ed346bab0 Change and clean the mutex lock interface.
mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)
2001-02-09 06:11:45 +00:00
Matthew Dillon
4e71e795a1 This commit represents work mainly submitted by Tor and slightly modified
by myself.  It solves a serious vm_map corruption problem that can occur
with the buffer cache when block sizes > 64K are used.  This code has been
heavily tested in -stable but only tested somewhat on -current.  An MFC
will occur in a few days.  My additions include the vm_map_simplify_entry()
and minor buffer cache boundry case fix.

Make the buffer cache use a system map for buffer cache KVM rather then a
normal map.

Ensure that VM objects are not allocated for system maps.  There were cases
where a buffer map could wind up with a backing VM object -- normally
harmless, but this could also result in the buffer cache blocking in places
where it assumes no blocking will occur, possibly resulting in corrupted
maps.

Fix a minor boundry case in the buffer cache size limit is reached that
could result in non-optimal code.

Add vm_map_simplify_entry() calls to prevent 'creeping proliferation'
of vm_map_entry's in the buffer cache's vm_map.  Previously only a simple
linear optimization was made.  (The buffer vm_map typically has only a
handful of vm_map_entry's.  This stabilizes it at that level permanently).

PR: 20609
Submitted by: (Tor Egge) tegge
2001-02-04 06:19:28 +00:00
Jake Burkholder
ef73ae4b0c Use PCPU_GET, PCPU_PTR and PCPU_SET to access all per-cpu variables
other then curproc.
2001-01-10 04:43:51 +00:00
Matthew Dillon
2b6b0df712 This implements a better launder limiting solution. There was a solution
in 4.2-REL which I ripped out in -stable and -current when implementing the
low-memory handling solution.  However, maxlaunder turns out to be the saving
grace in certain very heavily loaded systems (e.g. newsreader box).  The new
algorithm limits the number of pages laundered in the first pageout daemon
pass.  If that is not sufficient then suceessive will be run without any
limit.

Write I/O is now pipelined using two sysctls, vfs.lorunningspace and
vfs.hirunningspace.  This prevents excessive buffered writes in the
disk queues which cause long (multi-second) delays for reads.  It leads
to more stable (less jerky) and generally faster I/O streaming to disk
by allowing required read ops (e.g. for indirect blocks and such) to occur
without interrupting the write stream, amoung other things.

NOTE: eventually, filesystem write I/O pipelining needs to be done on a
per-device basis.  At the moment it is globalized.
2000-12-26 19:41:38 +00:00
John Baldwin
ffc831da27 Stick the kthread API in a kthread_* namespace, and the specialized kproc
functions in a kproc_* namespace.

Reviewed by:	-arch
2000-12-15 20:08:20 +00:00
Matthew Dillon
936524aa02 Implement a low-memory deadlock solution.
Removed most of the hacks that were trying to deal with low-memory
    situations prior to now.

    The new code is based on the concept that I/O must be able to function in
    a low memory situation.  All major modules related to I/O (except
    networking) have been adjusted to allow allocation out of the system
    reserve memory pool.  These modules now detect a low memory situation but
    rather then block they instead continue to operate, then return resources
    to the memory pool instead of cache them or leave them wired.

    Code has been added to stall in a low-memory situation prior to a vnode
    being locked.

    Thus situations where a process blocks in a low-memory condition while
    holding a locked vnode have been reduced to near nothing.  Not only will
    I/O continue to operate, but many prior deadlock conditions simply no
    longer exist.

Implement a number of VFS/BIO fixes

	(found by Ian): in biodone(), bogus-page replacement code, the loop
        was not properly incrementing loop variables prior to a continue
        statement.  We do not believe this code can be hit anyway but we
        aren't taking any chances.  We'll turn the whole section into a
        panic (as it already is in brelse()) after the release is rolled.

	In biodone(), the foff calculation was incorrectly
        clamped to the iosize, causing the wrong foff to be calculated
        for pages in the case of an I/O error or biodone() called without
        initiating I/O.  The problem always caused a panic before.  Now it
        doesn't.  The problem is mainly an issue with NFS.

	Fixed casts for ~PAGE_MASK.  This code worked properly before only
        because the calculations use signed arithmatic.  Better to properly
        extend PAGE_MASK first before inverting it for the 64 bit masking
        op.

	In brelse(), the bogus_page fixup code was improperly throwing
        away the original contents of 'm' when it did the j-loop to
        fix the bogus pages.  The result was that it would potentially
        invalidate parts of the *WRONG* page(!), leading to corruption.

	There may still be cases where a background bitmap write is
        being duplicated, causing potential corruption.  We have identified
        a potentially serious bug related to this but the fix is still TBD.
        So instead this patch contains a KASSERT to detect the problem
  	and panic the machine rather then continue to corrupt the filesystem.
	The problem does not occur very often..  it is very hard to
	reproduce, and it may or may not be the cause of the corruption
	people have reported.

Review by: (VFS/BIO: mckusick, Ian Dowse <iedowse@maths.tcd.ie>)
Testing by: (VM/Deadlock) Paul Saab <ps@yahoo-inc.com>
2000-11-18 23:06:26 +00:00
Poul-Henning Kamp
1d7e3e42e7 Take VBLK devices further out of their missery.
This should fix the panic I introduced in my previous commit on this topic.
2000-11-02 21:14:13 +00:00
John Baldwin
35e0e5b311 Catch up to moving headers:
- machine/ipl.h -> sys/ipl.h
- machine/mutex.h -> sys/mutex.h
2000-10-20 07:58:15 +00:00
Jason Evans
a18b1f1d4d Convert lockmgr locks from using simple locks to using mutexes.
Add lockdestroy() and appropriate invocations, which corresponds to
lockinit() and must be called to clean up after a lockmgr lock is no
longer needed.
2000-10-04 01:29:17 +00:00
Boris Popov
9ff5ce6baf Add three new VOPs: VOP_CREATEVOBJECT, VOP_DESTROYVOBJECT and VOP_GETVOBJECT.
They will be used by nullfs and other stacked filesystems to support full
cache coherency.

Reviewed in general by:	mckusick, dillon
2000-09-12 09:49:08 +00:00
Jason Evans
0384fff8c5 Major update to the way synchronization is done in the kernel. Highlights
include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
Kirk McKusick
54e53ebda7 Now that buffer locks can be recursive, we need to delete the panics
that complain about them.

Obtained from:	Brian Fundakowski Feldman <green@FreeBSD.org>
2000-07-25 18:28:46 +00:00
Kirk McKusick
f2a2857bb3 Add snapshots to the fast filesystem. Most of the changes support
the gating of system calls that cause modifications to the underlying
filesystem. The gating can be enabled by any filesystem that needs
to consistently suspend operations by adding the vop_stdgetwritemount
to their set of vnops. Once gating is enabled, the function
vfs_write_suspend stops all new write operations to a filesystem,
allows any filesystem modifying system calls already in progress
to complete, then sync's the filesystem to disk and returns. The
function vfs_write_resume allows the suspended write operations to
begin again. Gating is not added by default for all filesystems as
for SMP systems it adds two extra locks to such critical kernel
paths as the write system call. Thus, gating should only be added
as needed.

Details on the use and current status of snapshots in FFS can be
found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness
is not included here. Unless and until you create a snapshot file,
these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
Poul-Henning Kamp
a2e7a027a7 Virtualizes & untangles the bioops operations vector.
Ref: Message-ID: <18317.961014572@critter.freebsd.dk> To: current@
2000-06-16 08:48:51 +00:00
Jake Burkholder
e39756439c Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by:		msmith and others
2000-05-26 02:09:24 +00:00
Jake Burkholder
740a1973a6 Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by:	phk
Reviewed by:	phk
Approved by:	mdodd
2000-05-23 20:41:01 +00:00
Poul-Henning Kamp
9626b608de Separate the struct bio related stuff out of <sys/buf.h> into
<sys/bio.h>.

<sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall
not be made a nested include according to bdes teachings on the
subject of nested includes.

Diskdrivers and similar stuff below specfs::strategy() should no
longer need to include <sys/buf.> unless they need caching of data.

Still a few bogus uses of struct buf to track down.

Repocopy by:    peter
2000-05-05 09:59:14 +00:00
Poul-Henning Kamp
017ef345bc Give struct bio it's own call back mechanism. 2000-05-01 13:36:25 +00:00
Poul-Henning Kamp
95bdaa0ee8 Hmm, diff/patch still doesn't like me.
Missed one s/biowait/bufwait/g
2000-04-30 06:16:03 +00:00
Poul-Henning Kamp
87150cb06d s/biowait/bufwait/g
Prodded by: several.
2000-04-29 16:25:22 +00:00
Poul-Henning Kamp
c1462ad325 Remove a leftover dysonism. 2000-04-29 16:14:10 +00:00
Poul-Henning Kamp
3389ae9350 Remove ~25 unneeded #include <sys/conf.h>
Remove ~60 unneeded #include <sys/malloc.h>
2000-04-19 14:58:28 +00:00
Poul-Henning Kamp
19583a8007 Don't declare common variables in include files:
move buftimelock til vfs_bio.c where it is initialized.
2000-04-18 11:21:28 +00:00
Poul-Henning Kamp
8177437d85 Complete the bio/buf divorce for all code below devfs::strategy
Exceptions:
        Vinum untouched.  This means that it cannot be compiled.
        Greg Lehey is on the case.

        CCD not converted yet, casts to struct buf (still safe)

        atapi-cd casts to struct buf to examine B_PHYS
2000-04-15 05:54:02 +00:00
Poul-Henning Kamp
c244d2de43 Move B_ERROR flag to b_ioflags and call it BIO_ERROR.
(Much of this done by script)

Move B_ORDERED flag to b_ioflags and call it BIO_ORDERED.

Move b_pblkno and b_iodone_chain to struct bio while we transition, they
will be obsoleted once bio structs chain/stack.

Add bio_queue field for struct bio aware disksort.

Address a lot of stylistic issues brought up by bde.
2000-04-02 15:24:56 +00:00
Poul-Henning Kamp
8c125869a9 Draw the outline of "struct bio".
Struct bio is the future carrier of I/O requests for "struct buf".
2000-04-02 09:26:51 +00:00
Matthew Dillon
7c58e473f5 Commit the buffer cache cleanup patch to 4.x and 5.x. This patch fixes a
fragmentation problem due to geteblk() reserving too much space for the
    buffer and imposes a larger granularity (16K) on KVA reservations for
    the buffer cache to avoid fragmentation issues.  The buffer cache size
    calculations have been redone to simplify them (fewer defines, better
    comments, less chance of running out of KVA).

    The geteblk() fix solves a performance problem that DG was able reproduce.

    This patch does not completely fix the KVA fragmentation problems, but
    it goes a long way

Mostly Reviewed by: bde and others
Approved by: jkh
2000-03-27 21:29:33 +00:00
Poul-Henning Kamp
b99c307a21 Rename the existing BUF_STRATEGY() to DEV_STRATEGY()
substitute BUF_WRITE(foo) for VOP_BWRITE(foo->b_vp, foo)

substitute BUF_STRATEGY(foo) for VOP_STRATEGY(foo->b_vp, foo)

This patch is machine generated except for the ccd.c and buf.h parts.
2000-03-20 11:29:10 +00:00
Poul-Henning Kamp
21144e3bf1 Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new
field in struct buf: b_iocmd.  The b_iocmd is enforced to have
exactly one bit set.

B_WRITE was bogusly defined as zero giving rise to obvious coding
mistakes.

Also eliminate the redundant struct buf flag B_CALL, it can just
as efficiently be done by comparing b_iodone to NULL.

Should you get a panic or drop into the debugger, complaining about
"b_iocmd", don't continue.  It is likely to write on your disk
where it should have been reading.

This change is a step in the direction towards a stackable BIO capability.

A lot of this patch were machine generated (Thanks to style(9) compliance!)

Vinum users:  Greg has not had time to test this yet, be careful.
2000-03-20 10:44:49 +00:00
Poul-Henning Kamp
db5f635acc Eliminate the undocumented, experimental, non-delivering and highly
dangerous MAX_PERF option.
2000-03-16 08:51:55 +00:00
Kirk McKusick
71c87cfd7e Need to reset the buffer pointer to avoid reconsidering the same buffer
again (without this the rollback analysis was being lost). Should reduce
the write count for most workloads.

Submitted by:	Craig A Soules <soules+@andrew.cmu.edu>
2000-01-18 02:13:26 +00:00
Poul-Henning Kamp
ba4ad1fcea Give vn_isdisk() a second argument where it can return a suitable errno.
Suggested by:	bde
2000-01-10 12:04:27 +00:00
Kirk McKusick
cf60e8e4bf Several performance improvements for soft updates have been added:
1) Fastpath deletions. When a file is being deleted, check to see if it
   was so recently created that its inode has not yet been written to
   disk. If so, the delete can proceed to immediately free the inode.
2) Background writes: No file or block allocations can be done while the
   bitmap is being written to disk. To avoid these stalls, the bitmap is
   copied to another buffer which is written thus leaving the original
   available for futher allocations.
3) Link count tracking. Constantly track the difference in i_effnlink and
   i_nlink so that inodes that have had no change other than i_effnlink
   need not be written.
4) Identify buffers with rollback dependencies so that the buffer flushing
   daemon can choose to skip over them.
2000-01-10 00:24:24 +00:00
Luoqi Chen
5e95083920 Introduce a mechanism to suspend/resume system processes. Suspend syncer
and bufdaemon prior to disk sync during system shutdown.
2000-01-07 08:36:44 +00:00
Matthew Dillon
8f95b97072 Reimplement buf_daemon / getnewbuf() interaction for dealing with
stressful situations.  buf_daemon now makes a distinction between
    being woken up and its sleep timing out, and as a consequence is now
    much better able to dynamically tune itself to its environment.

Reviewed by:	Alfred Perlstein <bright@wintelcom.net>
1999-12-20 20:28:40 +00:00
Kirk McKusick
e9cc475851 Collect read and write counts for filesystems. This new code
drops the counting in bwrite and puts it all in spec_strategy.
I did some tests and verified that the counts collected for writes
in spec_strategy is identical to the counts that we previously
collected in bwrite. We now also get read counts (async reads
come from requests for read-ahead blocks). Note that you need
to compile a new version of mount to get the read counts printed
out. The old mount binary is completely compatible, the only
reason to install a new mount is to get the read counts printed.

Submitted by:	Craig A Soules <soules+@andrew.cmu.edu>
Reviewed by:	Kirk McKusick <mckusick@mckusick.com>
1999-12-01 02:09:30 +00:00
Poul-Henning Kamp
38224dcd59 Convert various pieces of code to use vn_isdisk() rather than checking
for vp->v_type == VBLK.

In ccd: we don't need to call VOP_GETATTR to find the type of a vnode.

Reviewed by:    sos
1999-11-22 10:33:55 +00:00
Poul-Henning Kamp
2e3c8fcbd0 This is a partial commit of the patch from PR 14914:
Alot of the code in sys/kern directly accesses the *Q_HEAD and *Q_ENTRY
   structures for list operations.  This patch makes all list operations
   in sys/kern use the queue(3) macros, rather than directly accessing the
   *Q_{HEAD,ENTRY} structures.

This batch of changes compile to the same object files.

Reviewed by:    phk
Submitted by:   Jake Burkholder <jake@checker.org>
PR:     14914
1999-11-16 10:56:05 +00:00
Poul-Henning Kamp
3f5bbb089a Remove a #define which doesn't do miracles anymore. 1999-10-30 09:31:52 +00:00
Poul-Henning Kamp
923502ff91 useracc() the prequel:
Merge the contents (less some trivial bordering the silly comments)
of <vm/vm_prot.h> and <vm/vm_inherit.h> into <vm/vm.h>.  This puts
the #defines for the vm_inherit_t and vm_prot_t types next to their
typedefs.

This paves the road for the commit to follow shortly: change
useracc() to use VM_PROT_{READ|WRITE} rather than B_{READ|WRITE}
as argument.
1999-10-29 18:09:36 +00:00
Matthew Dillon
9782fb6209 Adjust the buffer cache to better handle small-memory machines. A
slightly older version of this code was tested by BDE and I.

    Also fixes a lockup situation when kva gets too fragmented.

    Remove the maxvmiobufspace variable and sysctl, they are no longer
    used.  Also cleanup (remove) #if 0 sections from prior commits.

    This code is more of a hack, but presumably the whole buffer cache
    implementation is going to be rewritten in the next year so it's no
    big deal.
1999-10-24 03:27:28 +00:00
Peter Wemm
d1f088dab5 Trim unused options (or #ifdef for undoc options).
Submitted by:	phk
1999-10-11 15:19:12 +00:00
Dmitrij Tejblum
4c6fc7285e Count bogus_page as wired. 1999-09-30 07:39:20 +00:00
Matthew Dillon
d909b5635d Fix bug in brelse() regarding redirtying buffers on B_ERROR. brelse()
improperly ignored the B_INVAL flag when acting on the B_ERROR.
    If both B_INVAL and B_ERROR are set the buffer is typically out of the
    underlying device's block range and must be destroyed.  If only B_ERROR
    is set (for a write), a write error occured and operation remains as it
    was before:  the buffer must be redirtied to avoid corrupting the
    filesystem state.

Reviewed by:	David Greenman <dg@root.com>
Submitted by:	Tor.Egge@fast.no
1999-09-20 16:19:24 +00:00
Luoqi Chen
d8a31f810f Allow getblk() to be called from an idle context (by panic() inside
an interrupt handler).

Reviewed by:	dillon
1999-09-03 17:49:25 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Bruce Evans
d009ccfaf5 Cast pointers to uintptr_t instead of casting them to u_long, and/or vice
versa.  Cosmetic.
1999-08-24 00:56:50 +00:00
Poul-Henning Kamp
0ef1c82630 Decommision miscfs/specfs/specdev.h. Most of it goes into <sys/conf.h>,
a few lines into <sys/vnode.h>.

Add a few fields to struct specinfo, paving the way for the fun part.
1999-08-08 18:43:05 +00:00
Alan Cox
6745299365 Add sysctl and support code to allow directories to be VMIO'd. The default
setting for the sysctl is OFF, which is the historical operation.

Submitted by:	dillon
1999-07-26 06:25:53 +00:00
Peter Wemm
29a751bf4e bufhashinit() is called with a caddr_t and is expected to return the
same in both the alpha and i386 ports.
1999-07-09 16:41:19 +00:00