Commit Graph

208 Commits

Author SHA1 Message Date
Bosko Milekic
a5a262c6db Fix a INVARIANTS-only bug introduced in Revision 1.104:
IF INVARIANTS is defined, and in the rare case that we have
allocated some objects from the slab and at least one initializer
on at least one of those objects failed, and we need to fail the
allocation and push the uninitialized items back into the slab
caches -- in that scenario, we would fail to [re]set the
bucket cache's ub_bucket item references to NULL, which would
eventually trigger a KASSERT.
2004-10-27 21:19:35 +00:00
Brian Feldman
55fc8c1146 In the previous revision, I did not intend to change the default value
of "nosleepwithlocks."

Submitted by:	ru
2004-10-09 18:51:32 +00:00
Brian Feldman
ab14a3f7aa Fix critical stability problems that can cause UMA mbuf cluster
state management corruption, mbuf leaks, general mbuf corruption,
and at least on i386 a first level splash damage radius that
encompasses up to about half a megabyte of the memory after
an mbuf cluster's allocation slab.  In short, this has caused
instability nightmares anywhere the right kind of network traffic
is present.

When the polymorphic refcount slabs were added to UMA, the new types
were not used pervasively.  In particular, the slab management
structure was turned into one for refcounts, and one for non-refcounts
(supposed to be mostly like the old slab management structure),
but the latter was almost always used through out.  In general, every
access to zones with UMA_ZONE_REFCNT turned on corrupted the
"next free" slab offset offset and the refcount with each other and
with other allocations (on i386, 2 mbuf clusters per 4096 byte slab).

Fix things so that the right type is used to access refcounted zones
where it was not before.  There are additional errors in gross
overestimation of padding, it seems, that would cause a large kegs
(nee zones) to be allocated when small ones would do.  Unless I have
analyzed this incorrectly, it is not directly harmful.
2004-10-08 20:19:29 +00:00
Robert Watson
3659f747f1 Generate KTR trace records for uma_zalloc_arg() and uma_zfree_arg().
This doesn't trace every event of interest in UMA, but provides
enough basic information to explain lock traces and sleep patterns.
2004-08-06 21:52:38 +00:00
Brian Feldman
b23f72e98a * Add a "how" argument to uma_zone constructors and initialization functions
so that they know whether the allocation is supposed to be able to sleep
  or not.
* Allow uma_zone constructors and initialation functions to return either
  success or error.  Almost all of the ones in the tree currently return
  success unconditionally, but mbuf is a notable exception: the packet
  zone constructor wants to be able to fail if it cannot suballocate an
  mbuf cluster, and the mbuf allocators want to be able to fail in general
  in a MAC kernel if the MAC mbuf initializer fails.  This fixes the
  panics people are seeing when they run out of memory for mbuf clusters.
* Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing
  the default.

Both bmilekic and jeff have reviewed the changes made to make failable
zone allocations work.
2004-08-02 00:18:36 +00:00
Bosko Milekic
244f45548a Rework the way slab header storage space is calculated in UMA.
- zone_large_init() stays pretty much the same.
- zone_small_init() will try to stash the slab header in the slab page
  being allocated if the amount of calculated wasted space is less
  than UMA_MAX_WASTE (for both the UMA_ZONE_REFCNT case and regular
  case).  If the amount of wasted space is >= UMA_MAX_WASTE, then
  UMA_ZONE_OFFPAGE will be set and the slab header will be allocated
  separately for better use of space.
- uma_startup() calculates the maximum ipers required in offpage slabs
  (so that the offpage slab header zone(s) can be sized accordingly).
  The algorithm used to calculate this replaces the old calculation
  (which only happened to work coincidentally).  We now iterate over
  possible object sizes, starting from the smallest one, until we
  determine that wastedspace calculated in zone_small_init() might
  end up being greater than UMA_MAX_WASTE, at which point we use the
  found object size to compute the maximum possible ipers.  The
  reason this works is because:
      - wastedspace versus objectsize is a see-saw function with
        local minima all equal to zero and local maxima growing
        directly proportioned to objectsize.  This implies that
        for objects up to or equal a certain objectsize, the see-saw
        remains entirely below UMA_MAX_WASTE, so for those objectsizes
        it is impossible to ever go OFFPAGE for slab headers.
      - ipers (items-per-slab) versus objectsize is an inversely
        proportional function which falls off very quickly (very large
        for small objectsizes).
      - To determine the maximum ipers we'll ever need from OFFPAGE
        slab headers we first find the largest objectsize for which
        we are guaranteed to not go offpage for and use it to compute
        ipers (as though we were offpage).  Since the only objectsizes
        allowed to go offpage are bigger than the found objectsize,
        and since ipers vs objectsize is inversely proportional (and
        monotonically decreasing), then we are guaranteed that the
        ipers computed is always >= what we will ever need in offpage
        slab headers.
- Define UMA_FRITM_SZ and UMA_FRITMREF_SZ to be the actual (possibly
  padded) size of each freelist index so that offset calculations are
  fixed.

This might fix weird data corruption problems and certainly allows
ARM to now boot to at least single-user (via simulator).

Tested on i386 UP by me.
Tested on sparc64 SMP by fenner.
Tested on ARM simulator to single-user by cognet.
2004-07-29 15:25:40 +00:00
Alan Cox
5285558ac2 - Change uma_zone_set_obj() to call kmem_alloc_nofault() instead of
kmem_alloc_pageable().  The difference between these is that an errant
   memory access to the zone will be detected sooner with
   kmem_alloc_nofault().

The following changes serve to eliminate the following lock-order
reversal reported by witness:

 1st 0xc1a3c084 vm object (vm object) @ vm/swap_pager.c:1311
 2nd 0xc07acb00 swap_pager swhash (swap_pager swhash) @ vm/swap_pager.c:1797
 3rd 0xc1804bdc vm object (vm object) @ vm/uma_core.c:931

There is no potential deadlock in this case.  However, witness is unable
to recognize this because vm objects used by UMA have the same type as
ordinary vm objects.  To remedy this, we make the following changes:

 - Add a mutex type argument to VM_OBJECT_LOCK_INIT().
 - Use the mutex type argument to assign distinct types to special
   vm objects such as the kernel object, kmem object, and UMA objects.
 - Define a static swap zone object for use by UMA.  (Only static
   objects are assigned a special mutex type.)
2004-07-22 19:44:49 +00:00
Brian Feldman
0c3c862e21 Since breakage of malloc(9)/uma_zalloc(9) is totally non-optional in
GENERIC/for WITNESS users, make sure the sysctl to disable the behavior
is read-only and always enabled.
2004-07-19 15:05:24 +00:00
Bosko Milekic
0d0837ee6d Introduce debug.nosleepwithlocks sysctl, 0 by default. If set to 1
and WITNESS is not built, then force all M_WAITOK allocations to
M_NOWAIT behavior (transparently).  This is to be used temporarily
if wierd deadlocks are reported because we still have code paths
that perform M_WAITOK allocations with lock(s) held, which can
lead to deadlock.  If WITNESS is compiled, then the sysctl is ignored
and we ask witness to tell us wether we have locks held, converting
to M_NOWAIT behavior only if it tells us that we do.

Note this removes the previous mbuf.h inclusion as well (only needed
by last revision), and cleans up unneeded [artificial] comparisons
to just the mbuf zones.  The problem described above has nothing to
do with previous mbuf wait behavior; it is a general problem.
2004-07-04 16:07:44 +00:00
Brian Feldman
7a708c3626 Reextend the M_WAITOK-disabling-hack to all three of the mbuf-related
zones, and do it by direct comparison of uma_zone_t instead of strcmp.

The mbuf subsystem used to provide M_TRYWAIT/M_DONTWAIT semantics, but
this is mostly no longer the case.  M_WAITOK has taken over the spot
M_TRYWAIT used to have, and for mbuf things, still may return NULL if
the code path is incorrectly holding a mutex going into mbuf allocation
functions.

The M_WAITOK/M_NOWAIT semantics are absolute; though it may deadlock
the system to try to malloc or uma_zalloc something with a mutex held
and M_WAITOK specified, it is absolutely required to not return NULL
and will result in instability and/or security breaches otherwise.
There is still room to add the WITNESS_WARN() to all cases so that
we are notified of the possibility of deadlocks, but it cannot change
the value of the "badness" variable and allow allocation to actually
fail except for the specialized cases which used to be M_TRYWAIT.
2004-07-04 15:59:25 +00:00
Brian Feldman
cf107c1d1a Limit mbuma damage. Suddenly ALL allocations with M_WAITOK are subject
to failing -- that is, allocations via malloc(M_WAITOK) that are required
to never fail -- if WITNESS is not defined.  While everyone should be
running WITNESS, in any case, zone "Mbuf" allocations are really the only
ones that should be screwed with by this hack.

This hack is crashing people, and would continue to do so with or without
WITNESS.  Things shouldn't be allocating with M_WAITOK with locks held,
but it's not okay just to always remove M_WAITOK when !WITNESS.

Reported by:	Bernd Walter <ticso@cicely5.cicely.de>
2004-07-03 18:11:41 +00:00
Bosko Milekic
cc822cb53e Make uma_mtx MTX_RECURSE. Here's why:
The general UMA lock is a recursion-allowed lock because
there is a code path where, while we're still configured
to use startup_alloc() for backend page allocations, we
may end up in uma_reclaim() which calls zone_foreach(zone_drain),
which grabs uma_mtx, only to later call into startup_alloc()
because while freeing we needed to allocate a bucket.  Since
startup_alloc() also takes uma_mtx, we need to be able to
recurse on it.

This exact explanation also added as comment above mtx_init().

Trace showing recursion reported by: Peter Holm <peter-at-holm.cc>
2004-06-23 21:59:03 +00:00
Bosko Milekic
7fd8788213 Backout previous change, I think Julian has a better solution which
does not require type-stable refcnts here.
2004-06-09 20:50:08 +00:00
Bosko Milekic
e66468ea7a Make the slabrefzone, the zone from which we allocated slabs with
internal reference counters, UMA_ZONE_NOFREE.  This way, those slabs
(with their ref counts) will be effectively type-stable, then using
a trick like this on the refcount is no longer dangerous:

        MEXT_REM_REF(m);
        if (atomic_cmpset_int(m->m_ext.ref_cnt, 0, 1)) {
                if (m->m_ext.ext_type == EXT_PACKET) {
                        uma_zfree(zone_pack, m);
                        return;
                } else if (m->m_ext.ext_type == EXT_CLUSTER) {
                        uma_zfree(zone_clust, m->m_ext.ext_buf);
                        m->m_ext.ext_buf = NULL;
                } else {
                        (*(m->m_ext.ext_free))(m->m_ext.ext_buf,
                            m->m_ext.ext_args);
                        if (m->m_ext.ext_type != EXT_EXTREF)
                                free(m->m_ext.ref_cnt, M_MBUF);
                }
        }
        uma_zfree(zone_mbuf, m);

Previously, a second thread hitting the above cmpset might
actually read the refcnt AFTER it has already been freed.  A very
rare occurance.  Now we'll know that it won't be freed, though.

Spotted by: julian, pjd
2004-06-09 19:18:50 +00:00
Bosko Milekic
099a0e588c Bring in mbuma to replace mballoc.
mbuma is an Mbuf & Cluster allocator built on top of a number of
extensions to the UMA framework, all included herein.

Extensions to UMA worth noting:
  - Better layering between slab <-> zone caches; introduce
    Keg structure which splits off slab cache away from the
    zone structure and allows multiple zones to be stacked
    on top of a single Keg (single type of slab cache);
    perhaps we should look into defining a subset API on
    top of the Keg for special use by malloc(9),
    for example.
  - UMA_ZONE_REFCNT zones can now be added, and reference
    counters automagically allocated for them within the end
    of the associated slab structures.  uma_find_refcnt()
    does a kextract to fetch the slab struct reference from
    the underlying page, and lookup the corresponding refcnt.

mbuma things worth noting:
  - integrates mbuf & cluster allocations with extended UMA
    and provides caches for commonly-allocated items; defines
    several zones (two primary, one secondary) and two kegs.
  - change up certain code paths that always used to do:
    m_get() + m_clget() to instead just use m_getcl() and
    try to take advantage of the newly defined secondary
    Packet zone.
  - netstat(1) and systat(1) quickly hacked up to do basic
    stat reporting but additional stats work needs to be
    done once some other details within UMA have been taken
    care of and it becomes clearer to how stats will work
    within the modified framework.

From the user perspective, one implication is that the
NMBCLUSTERS compile-time option is no longer used.  The
maximum number of clusters is still capped off according
to maxusers, but it can be made unlimited by setting
the kern.ipc.nmbclusters boot-time tunable to zero.
Work should be done to write an appropriate sysctl
handler allowing dynamic tuning of kern.ipc.nmbclusters
at runtime.

Additional things worth noting/known issues (READ):
   - One report of 'ips' (ServeRAID) driver acting really
     slow in conjunction with mbuma.  Need more data.
     Latest report is that ips is equally sucking with
     and without mbuma.
   - Giant leak in NFS code sometimes occurs, can't
     reproduce but currently analyzing; brueffer is
     able to reproduce but THIS IS NOT an mbuma-specific
     problem and currently occurs even WITHOUT mbuma.
   - Issues in network locking: there is at least one
     code path in the rip code where one or more locks
     are acquired and we end up in m_prepend() with
     M_WAITOK, which causes WITNESS to whine from within
     UMA.  Current temporary solution: force all UMA
     allocations to be M_NOWAIT from within UMA for now
     to avoid deadlocks unless WITNESS is defined and we
     can determine with certainty that we're not holding
     any locks when we're M_WAITOK.
   - I've seen at least one weird socketbuffer empty-but-
     mbuf-still-attached panic.  I don't believe this
     to be related to mbuma but please keep your eyes
     open, turn on debugging, and capture crash dumps.

This change removes more code than it adds.

A paper is available detailing the change and considering
various performance issues, it was presented at BSDCan2004:
http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf
Please read the paper for Future Work and implementation
details, as well as credits.

Testing and Debugging:
    rwatson,
    brueffer,
    Ketrien I. Saihr-Kesenchedra,
    ...
Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
Alan Cox
5d328ed44b - Make the acquisition of Giant in vm_fault_unwire() conditional on the
pmap.  For the kernel pmap, Giant is not required.  In general, for
   other pmaps, Giant is required by i386's pmap_pte() implementation.
   Specifically, the use of PMAP2/PADDR2 is synchronized by Giant.
   Note: In principle, updates to the kernel pmap's wired count could be
   lost without Giant.  However, in practice, we never use the kernel
   pmap's wired count.  This will be resolved when pmap locking appears.
 - With the above change, cpu_thread_clean() and uma_large_free() need
   not acquire Giant.  (The first case is simply the revival of
   i386/i386/vm_machdep.c's revision 1.226 by peter.)
2004-03-10 04:44:43 +00:00
Robert Watson
a3c0761103 Mark uma_callout as CALLOUT_MPSAFE, as uma_timeout can run MPSAFE.
Reviewed by:	jeff
2004-03-07 07:00:46 +00:00
Jeff Roberson
aaa8bb1604 - Fix a problem where we did not drain the cache of buckets in the zone
when uma_reclaim() was called.  This was introduced when the zone
   working-set algorithm was removed in favor of using the per cpu caches
   as the working set.
2004-02-01 06:15:17 +00:00
Dag-Erling Smørgrav
e726bc0e6c Mechanical whitespace cleanup. 2004-01-30 16:26:29 +00:00
John Baldwin
b6c71225a9 Fix all users of mp_maxid to use the same semantics, namely:
1) mp_maxid is a valid FreeBSD CPU ID in the range 0 .. MAXCPU - 1.
2) For all active CPUs in the system, PCPU_GET(cpuid) <= mp_maxid.

Approved by:	re (scottl)
Tested on:	i386, amd64, alpha
2003-12-03 14:57:26 +00:00
Jeff Roberson
e30b97c5f9 - Unbreak UP. mp_maxid is not defined on uni-processor machines, although
I believe it and the other MP variables should be.  For now, just define it
   here and wait for jhb to clean it up later.

Approved by:	re (rwatson)
2003-11-30 22:18:14 +00:00
Jeff Roberson
504d5de3a8 - Replace the local maxcpu with mp_maxid. Previously, if mp_maxid
was equal to MAXCPU, we would overrun the pcpu_mtx array because maxcpu
   was calculated incorrectly.
 - Add some more debugging code so that memory leaks at the time of
   uma_zdestroy() are more easily diagnosed.

Approved by:	re (rwatson)
2003-11-30 08:04:01 +00:00
Alan Cox
d1f42ac2ee - Remove use of Giant from uma_zone_set_obj(). 2003-11-14 17:49:07 +00:00
Jeff Roberson
009b6fcb03 - Fix MD_SMALL_ALLOC on architectures that support it. Define a new alloc
function, startup_alloc(), that is used for single page allocations prior
   to the VM starting up.  If it is used after the VM startups up, it
   replaces the zone's allocf pointer with either page_alloc() or
   uma_small_alloc() where appropriate.

Pointy hat to:	me
Tested by:	phk/amd64, me/x86
2003-09-21 07:39:16 +00:00
Peter Wemm
c43ab0b5a1 Bad Jeffr! No cookie!
Temporarily disable the UMA_MD_SMALL_ALLOC stuff since recent commits
break sparc64, amd64, ia64 and alpha.  It appears only i386 and maybe
powerpc were not broken.
2003-09-20 23:35:33 +00:00
Jeff Roberson
9643769a3a - Remove the working-set algorithm. Instead, use the per cpu buckets as the
working set cache.  This has several advantages.  Firstly, we never touch
   the per cpu queues now in the timeout handler.  This removes one more
   reason for having per cpu locks.  Secondly, it reduces the size of the zone
   by 8 bytes, bringing it under 200 bytes for a single proc x86 box.  This
   tidies up other logic as well.
 - The 'destroy' flag no longer needs to be passed to zone_drain() since it
   always frees everything in the zone's slabs.
 - cache_drain() is now only called from zone_dtor() and so it destroys by
   default.  It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
Jeff Roberson
3e0cab95c0 - Remove the cache colorization code. We can't use it due to all of the
broken consumers of the malloc interface who assume that the allocated
   address will be an even multiple of the size.
 - Remove disabled time delay code on uma_reclaim().  The comment there said
   it all.  It was not an effective strategy and it should not be left in
   #if 0'd for all eternity.
2003-09-19 23:04:44 +00:00
Jeff Roberson
64f051e99a - There are an endless stream of style(9) errors in this file. Fix a few.
Also catch some spelling errors.
2003-09-19 22:31:45 +00:00
Jeff Roberson
44eca34adb - Don't inspect the zone in page_alloc(). It may be NULL.
- Don't cache more items than the zone would like in uma_zalloc_bucket().
2003-09-19 09:22:04 +00:00
Jeff Roberson
45bf76f0f8 - Move the logic for dealing with the uma_boot_pages cache into the
page_alloc() function from the slab_zalloc() function.  This allows us
   to unconditionally call uz_allocf().
 - In page_alloc() cleanup the boot_pages logic some.  Previously memory from
   this cache that was not used by the time the system started was left in
   the cache and never used.  Typically this wasn't more than a few pages,
   but now we will use this cache so long as memory is available.
2003-09-19 08:53:33 +00:00
Jeff Roberson
b60f5b794e - Fix the silly flag situation in UMA. Remove redundant ZFLAG/ZONE flags
by accepting the user supplied flags directly.  Previously this was not
   done so that flags for the same field would not be defined in two
   different files.  Add comments in each header instructing future
   developers on how now to shoot their feet.
 - Fix a test for !OFFPAGE which should have been a test for HASH.  This would
   have caused a panic if we had ever destructed a malloc zone.  This also
   opens up the possibility that other zones could use the vsetobj() method
   rather than a hash.
2003-09-19 08:37:44 +00:00
Jeff Roberson
961647dfd0 - Don't abuse M_DEVBUF, define a tag for UMA hashes. 2003-09-19 07:23:50 +00:00
Jeff Roberson
b983089a05 - Eliminate a pair of unnecessary variables. 2003-09-19 06:41:06 +00:00
Jeff Roberson
cae33c1429 - Initialize a pool of bucket zones so that we waste less space on zones that
don't cache as many items.
 - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket
   allocation.  These functions select the appropriate bucket zone to
   allocate from or free to.
 - Rename ub_ptr to ub_cnt to reflect a change in its use.  ub_cnt now reflects
   the count of free items in the bucket.  This gets rid of many unnatural
   subtractions by 1 throughout the code.
 - Add ub_entries which reflects the number of entries possibly held in a
   bucket.
2003-09-19 06:26:45 +00:00
Bosko Milekic
1c35e213f1 In sysctl_vm_zone, do not calculate per-cpu cache stats on
UMA_ZFLAG_INTERNAL zones at all.  Apparently, Wilko's alpha
was crashing while entering multi-user because, I think, we
were calculating the garbage cachefree for pcpu caches that
essentially don't exist for at least the 'zones' zone and it so
happened that we were reading from an unmapped location.

Confirmed to fix crash: wilko
Helped debug: wilko, gallatin
2003-08-20 18:22:06 +00:00
Bosko Milekic
20e8e865bd - When deciding whether to init the zone with small_init or large_init,
compare the zone element size (+1 for the byte of linkage) against
  UMA_SLAB_SIZE - sizeof(struct uma_slab), and not just UMA_SLAB_SIZE.
  Add a KASSERT in zone_small_init to make sure that the computed
  ipers (items per slab) for the zone is not zero, despite the addition
  of the check, just to be sure (this part submitted by: silby)

- UMA_ZONE_VM used to imply BUCKETCACHE.  Now it implies
  CACHEONLY instead.  CACHEONLY is like BUCKETCACHE in the
  case of bucket allocations, but in addition to that also ensures that
  we don't setup the zone with OFFPAGE slab headers allocated from the
  slabzone.  This means that we're not allowed to have a UMA_ZONE_VM
  zone initialized for large items (zone_large_init) because it would
  require the slab headers to be allocated from slabzone, and hence
  kmem_map.  Some of the zones init'd with UMA_ZONE_VM are so init'd
  before kmem_map is suballoc'd from kernel_map, which is why this
  change is necessary.
2003-08-11 19:39:45 +00:00
Alan Cox
b245ac95cf Revise obj_alloc(). Most notably, use the object's lock to prevent two
concurrent invocations from acquiring the same address(es).  Also, in case
of an incomplete allocation, free any allocated pages.

In collaboration with:	tegge
2003-08-03 06:08:48 +00:00
Bosko Milekic
48bf87258f When INVARIANTS is on and we're in uma_zalloc_free(), we need to make
sure that uma_dbg_free() is called if we're about to call
uma_zfree_internal() but we're asking it to skip the dtor and
uma_dbg_free() call itself.  So, if we're about to call
uma_zfree_internal() from uma_zfree_arg() and skip == 1, call
uma_dbg_free() ourselves.
2003-08-02 22:40:27 +00:00
Bosko Milekic
174ab4501e Only free the pcpu cache buckets if they are non-NULL.
Crashed this person's machine: harti
Pointy-hat to: me
2003-08-01 17:42:27 +00:00
Bosko Milekic
d56368d779 Plug a race and a leak in UMA.
1) The race has to do with zone destruction.  From the zone destructor we
   would lock the zone, set the working set size to 0, then unlock the zone,
   drain it, and then free the structure.  Within the window following the
   working-set-size set to 0 and unlocking of the zone and the point where
   in zone_drain we re-acquire the zone lock, the uma timer routine could
   have fired off and changed the working set size to something non-zero,
   thereby potentially preventing us from completely freeing slabs before
   destroying the zone (and thus leaking them).

2) The leak has to do with zone destruction as well.  When destroying a
   zone we would take care to free all the buckets cached in the zone, but
   although we would drain the pcpu cache buckets, we would not free them.
   This resulted in leaking a couple of bucket structures (512 bytes each)
   per cpu on SMP during zone destruction.

While I'm here, also silence GCC warnings by turning uma_slab_alloc()
from inline to real function.  It's too big to be an inline.

Reviewed by: JeffR
2003-07-30 18:55:15 +00:00
Bosko Milekic
a40fdcb439 When generating the zone stats make sure to handle the master zone
("UMA Zone") carefully, because it does not have pcpu caches allocated
at all.  In the UP case, we did not catch this because one pcpu cache
is always allocated with the zone, but for the MP case, we were getting
bogus stats for this zone.

Tested by: Lukas Ertl <le@univie.ac.at>
2003-07-30 15:22:37 +00:00
Poul-Henning Kamp
7b4bd98ad5 Remove the disabling of buckets workaround.
Thanks to:	jeffr
2003-07-30 07:50:19 +00:00
Jeff Roberson
f828e5bedb - Get rid of the ill-conceived uz_cachefree member of uma_zone.
- In sysctl_vm_zone use the per cpu locks to read the current cache
   statistics this makes them more accurate while under heavy load.

Submitted by:	tegge
2003-07-30 05:59:17 +00:00
Jeff Roberson
d11e0ba565 - Check to see if we need a slab prior to allocating one. Failure to do
so not only wastes memory but it can also cause a leak in zones that
   will be destroyed later.  The problem is that the slab allocation code
   places newly created slabs on the partially allocated list because it
   assumes that the caller will actually allocate some memory from it.
   Failure to do so places an otherwise free slab on the partial slab list
   where we wont find it later in zone_drain().

Continuously prodded to fix by:	phk (Thanks)
2003-07-30 05:42:55 +00:00
Poul-Henning Kamp
0c32d97ab5 Temporary workaround: Always disable buckets, there is a bug there
somewhere.

JeffR will look at this as soon as he has time.

OK'ed by:	jeffr
2003-07-29 22:07:10 +00:00
Alan Cox
234c7726c8 None of the "alloc" functions used by UMA assume that Giant is held any
longer.  (If they still need it, e.g., contigmalloc(), they acquire it
themselves.)  Therefore, we need not acquire Giant in slab_zalloc().
2003-07-28 02:29:07 +00:00
Alan Cox
0c1a133f56 Gulp ... call kmem_malloc() without Giant. 2003-07-26 03:55:32 +00:00
Hartmut Brandt
8522511b2a When INVARIANTS is defined make sure that uma_zalloc_arg (and hence
uma_zalloc) is called with exactly one of either M_WAITOK or M_NOWAIT and
that it is called with neither M_TRYWAIT or M_DONTWAIT. Print a warning
if anything is wrong. Default to M_WAITOK of no flag is given. This is the
same test as in malloc(9).
2003-07-18 16:04:36 +00:00
Bosko Milekic
d88797c2ba Move the pcpu lock out of the uma_cache and instead have a single set
of pcpu locks.  This makes uma_zone somewhat smaller (by (LOCKNAME_LEN *
sizeof(char) + sizeof(struct mtx) * maxcpu) bytes, to be exact).

No Objections from jeff.
2003-06-25 20:49:48 +00:00
Bosko Milekic
5c133dfa0e Make sure that the zone destructor doesn't get called twice in
certain free paths.
2003-06-25 17:25:45 +00:00
David E. O'Brien
874651b13c Use __FBSDID(). 2003-06-11 23:50:51 +00:00
Poul-Henning Kamp
c1f5a18201 Revert last commit, I have no idea what happened. 2003-06-09 22:51:36 +00:00
Poul-Henning Kamp
47f94c12da A white-space nit I noticed. 2003-06-09 19:40:34 +00:00
Alan Cox
82774d8040 uma_zone_set_obj() must perform VM_OBJECT_LOCK_INIT() if the caller
provides storage for the vm_object.
2003-04-28 06:11:32 +00:00
Alan Cox
5103186c8c Remove an XXX comment. It is no longer a problem. 2003-04-26 05:00:56 +00:00
Alan Cox
410cfc455e Lock the vm_object in obj_alloc(). 2003-04-19 00:30:36 +00:00
Andrew Gallatin
b37d8ead52 Don't grab Giant in slab_zalloc() if M_NOWAIT is specified. This
should allow the use of INTR_MPSAFE network drivers.

Tested by: njl
Glanced at by: jeff
2003-04-18 13:02:29 +00:00
Tor Egge
125ee0d161 Obtain Giant before calling kmem_alloc without M_NOWAIT and before calling
kmem_free if Giant isn't already held.
2003-03-26 18:44:53 +00:00
John Baldwin
263067951a Replace calls to WITNESS_SLEEP() and witness_list() with equivalent calls
to WITNESS_WARN().
2003-03-04 21:03:05 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Poul-Henning Kamp
886eaaacfa Change a printf to also tell how many items were left in the zone. 2003-02-04 08:23:18 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Jeff Roberson
ebc85edf5e - M_WAITOK is 0 and not a real flag. Test for this properly.
Submitted by:	tmm
Pointy hat to:	jeff
2003-01-20 01:32:56 +00:00
Jens Schweikhardt
9d5abbddbf Correct typos, mostly s/ a / an / where appropriate. Some whitespace cleanup,
especially in troff files.
2003-01-01 18:49:04 +00:00
Jeff Roberson
74c924b553 - Wakeup the correct address when a zone is no longer full.
Spotted by:	jake
2002-11-18 08:27:14 +00:00
Jeff Roberson
f3da1873bc - Don't forget the flags value when using boot pages.
Reported by:	grehan
2002-11-16 20:57:41 +00:00
Matt Jacob
81f71edaec atomic_set_8 isn't MI. Instead, follow Jake's suggestions about
ZONE_LOCK.
2002-11-11 11:50:03 +00:00
Jeff Roberson
48eea37508 - Add support for machine dependant page allocation routines. MD code
may define UMA_MD_SMALL_ALLOC to make use of this feature.

Reviewed by:	peter, jake
2002-11-01 01:01:27 +00:00
Jeff Roberson
bbee39c629 - Now that uma_zalloc_internal is not the fast path don't be so fussy about
extra function calls.  Refactor uma_zalloc_internal into seperate functions
   for finding the most appropriate slab, filling buckets, allocating single
   items, and pulling items off of slabs.  This makes the code significantly
   cleaner.
 - This also fixes the "Returning an empty bucket." panic that a few people
   have seen.

Tested On:	alpha, x86
2002-10-24 07:59:03 +00:00
Jeff Roberson
bba739abf9 - Move the destructor calls so that they are not called with the zone lock
held.  This avoids a lock order reversal when destroying zones.
   Unfortunately, this also means that the free checks are not done before
   the destructor is called.

Reported by:	phk
2002-10-24 06:17:30 +00:00
Poul-Henning Kamp
37c841831f Be consistent about "static" functions: if the function is marked
static in its prototype, mark it static at the definition too.

Inspired by:    FlexeLint warning #512
2002-09-28 17:15:38 +00:00
Jeff Roberson
f461cf2297 - Use my freebsd email alias in the copyright.
- Remove redundant instances of my email alias in the file summary.
2002-09-19 06:05:32 +00:00
Jeff Roberson
99571dc345 - Split UMA_ZFLAG_OFFPAGE into UMA_ZFLAG_OFFPAGE and UMA_ZFLAG_HASH.
- Remove all instances of the mallochash.
 - Stash the slab pointer in the vm page's object pointer when allocating from
   the kmem_obj.
 - Use the overloaded object pointer to find slabs for malloced memory.
2002-09-18 08:26:30 +00:00
Archie Cobbs
55f7c614fd Don't use "NULL" when "0" is really meant. 2002-08-21 23:39:52 +00:00
Jeff Roberson
17b9cc4941 Fix a lock order reversal in uma_zdestroy. The uma_mtx needs to be held across
calls to zone_drain().

Noticed by:	scottl
2002-07-05 21:39:52 +00:00
Jeff Roberson
f5118d6aaf Remove unnecessary includes. 2002-07-05 05:16:19 +00:00
Jeff Roberson
e221e841b0 Actually use the fini callback.
Pointy hat to:	me :-(
Noticed By:	Julian
2002-07-03 00:30:51 +00:00
Jeff Roberson
5c0e403ba2 Reduce the amount of code that runs with the zone lock held in slab_zalloc().
This allows us to run the zone initialization functions without any locks held.
2002-06-25 21:04:50 +00:00
Jeff Roberson
3370c5bfd7 - Remove bogus use of kmem_alloc that was inherited from the old zone
allocator.
- Properly set M_ZERO when talking to the back end page allocators for
  non malloc zones.  This forces us to zero fill pages when they are first
  brought into a cache.
- Properly handle M_ZERO in uma_zalloc_internal.  This fixes a problem where
  per cpu buckets weren't always getting zeroed.
2002-06-19 20:49:44 +00:00
Jeff Roberson
4741dcbff5 Honor the BUCKETCACHE flag on free as well. 2002-06-17 23:53:58 +00:00
Jeff Roberson
18aa2de5a7 - Introduce the new M_NOVM option which tells uma to only check the currently
allocated slabs and bucket caches for free items.  It will not go ask the vm
  for pages.  This differs from M_NOWAIT in that it not only doesn't block, it
  doesn't even ask.

- Add a new zcreate option ZONE_VM, that sets the BUCKETCACHE zflag.  This
  tells uma that it should only allocate buckets out of the bucket cache, and
  not from the VM.  It does this by using the M_NOVM option to zalloc when
  getting a new bucket.  This is so that the VM doesn't recursively enter
  itself while trying to allocate buckets for vm_map_entry zones.  If there
  are already allocated buckets when we get here we'll still use them but
  otherwise we'll skip it.

- Use the ZONE_VM flag on vm map entries and pv entries on x86.
2002-06-17 22:02:41 +00:00
Ian Dowse
f97d6ce396 Correct the logic for determining whether the per-CPU locks need
to be destroyed. This fixes a problem where destroying a UMA zone
would fail to destroy all zone mutexes.

Reviewed by:	jeff
2002-06-10 03:25:23 +00:00
Jeff Roberson
494273bead Add a comment describing a resource leak that occurs during a failure case
in obj_alloc.
2002-06-03 22:59:19 +00:00
John Baldwin
4c1cc01cd8 In uma_zalloc_arg(), if we are performing a M_WAITOK allocation, ensure
that td_intr_nesting_level is 0 (like malloc() does).  Since malloc() calls
uma we can probably remove the check in malloc() for this now.  Also,
perform an extra witness check in that case to make sure we don't hold
any locks when performing a M_WAITOK allocation.
2002-05-20 17:54:48 +00:00
Jeff Roberson
713deb3677 Don't call the uz free function while the zone lock is held. This can lead
to lock order reversals.  uma_reclaim now builds a list of freeable slabs and
then unlocks the zones to do all of the frees.
2002-05-13 05:08:18 +00:00
Jeff Roberson
0aef6126a1 Remove the hash_free() lock order reversal. This could have happened for
several reasons before.  Fixing it involved restructuring the generic hash
code to require calling code to handle locking, unlocking, and freeing hashes
on error conditions.
2002-05-13 04:39:28 +00:00
Jeff Roberson
c7173f58fa Use pages instead of uz_maxpages, which has not been initialized yet, when
creating the vm_object.  This was broken after the code was rearranged to
grab giant itself.

Spotted by:     alc
2002-05-04 21:49:29 +00:00
Jeff Roberson
b9ba893179 Move around the dbg code a bit so it's always under a lock. This stops a
weird potential race if we were preempted right as we were doing the dbg
checks.
2002-05-02 09:05:36 +00:00
Andrew R. Reiter
c3bdc05fb9 - Changed the size element of uma_zctor_args to be size_t instead of int.
- Changed uma_zcreate to accept the size argument as a size_t intead of
  int.

Approved by:	jeff
2002-05-02 07:36:30 +00:00
Jeff Roberson
5a34a9f089 malloc/free(9) no longer require Giant. Use the malloc_mtx to protect the
mallochash.  Mallochash is going to go away as soon as I introduce the
kfree/kmalloc api and partially overhaul the malloc wrapper.  This can't happen
until all users of the malloc api that expect memory to be aligned on the size
of the allocation are fixed.
2002-05-02 07:22:19 +00:00
Jeff Roberson
639c9550fb Remove the temporary alignment check in free().
Implement the following checks on freed memory in the bucket path:
	- Slab membership
	- Alignment
	- Duplicate free

This previously was only done if we skipped the buckets.  This code will slow
down INVARIANTS a bit, but it is smp safe.  The checks were moved out of the
normal path and into hooks supplied in uma_dbg.
2002-05-02 02:08:48 +00:00
Jeff Roberson
2cc35ff9c6 Move the implementation of M_ZERO into UMA so that it can be passed to
uma_zalloc and friends.  Remove this functionality from the malloc wrapper.

Document this change in uma.h and adjust variable names in uma_core.
2002-04-30 04:26:34 +00:00
Jeff Roberson
28bc44195c Add a new zone flag UMA_ZONE_MTXCLASS. This puts the zone in it's own
mutex class.  Currently this is only used for kmapentzone because kmapents
are are potentially allocated when freeing memory.  This is not dangerous
though because no other allocations will be done while holding the
kmapentzone lock.
2002-04-29 23:45:41 +00:00
Andrew R. Reiter
d4d6aee5a0 - Fix a round down bogon in uma_zone_set_max().
Submitted by: jeff@
2002-04-25 06:24:40 +00:00
Jeff Roberson
5300d9dda2 Fix a witness warning when expanding a hash table. We were allocating the new
hash while holding the lock on a zone.  Fix this by doing the allocation
seperately from the actual hash expansion.

The lock is dropped before the allocation and reacquired before the expansion.
The expansion code checks to see if we lost the race and frees the new hash
if we do.  We really never will lose this race because the hash expansion is
single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
Jeff Roberson
0da47b2fc6 Protect the initial list traversal in sysctl_vm_zone() with the uma_mtx. 2002-04-14 12:39:38 +00:00
Jeff Roberson
af7f9b97b6 Fix the calculation that determines uz_maxpages. It was off for large zones.
Fortunately we have no large zones with maximums specified yet, so it wasn't
breaking anything.

Implement blocking when a zone exceeds the maximum and M_WAITOK is specified.
Previously this just failed like the old zone allocator did.  The old zone
allocator didn't support WAITOK/NOWAIT though so we should do what we
advertise.

While I was in there I cleaned up some more zalloc logic to further simplify
that code path and reduce redundant code.  This was needed to make the blocking
work properly anyway.
2002-04-14 01:56:25 +00:00
Jeff Roberson
bce9779110 Remember to unlock the zone if the fill count is too high.
Pointed out by:	pete, jake, jhb
2002-04-10 01:52:50 +00:00
Jeff Roberson
86bbae32f4 Add a mechanism to disable buckets when the v_free_count drops below
v_free_min.  This should help performance in memory starved situations.
2002-04-08 06:20:34 +00:00
Jeff Roberson
605cbd6a08 Don't release the zone lock until after the dtor has been called. As far as I
can tell this could not have caused any problems yet because UMA is still
called with giant.

Pointy hat to:	jeff
Noticed by:	jake
2002-04-08 05:13:48 +00:00
Jeff Roberson
9c2cd7e5a9 Implement uma_zdestroy(). It's prototype changed slightly. I decided that I
didn't like the wait argument and that if you were removing a zone it had
better be empty.

Also, I broke out part of hash_expand and made a seperate hash_free() for use
in uma_zdestroy.
2002-04-08 04:48:58 +00:00
Jeff Roberson
a553d4b8eb Rework most of the bucket allocation and free code so that per cpu locks are
never held across blocking operations.  Also, fix two other lock order
reversals that were exposed by jhb's witness change.

The free path previously had a bug that would cause it to skip the free bucket
list in some cases and go straight to allocating a new bucket.  This has been
fixed as well.

These changes made the bucket handling code much cleaner and removed quite a
few lock operations.  This should be marginally faster now.

It is now possible to call malloc w/o Giant and avoid any witness warnings.
This still isn't entirely safe though because malloc_type statistics are not
protected by any lock.
2002-04-08 02:42:55 +00:00
Jeff Roberson
d0b06acbe1 This fixes a bug where isitem never got set to 1 if a certain chain of events
relating to extreme low memory situations occured.  This was only ever seen on
the port build cluster, so many thanks to kris for helping me debug this.

Tested by:	kris
2002-04-07 22:47:36 +00:00
John Baldwin
6008862bc2 Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on:	i386, alpha, sparc64
2002-04-04 21:03:38 +00:00
Alfred Perlstein
157d7b3538 fix comment typo, s/neccisary/necessary/g 2002-04-02 21:25:12 +00:00
Jeff Roberson
f4af24d55d Reset the cachefree statistics after draining the cache. This fixes a bug
where a sysctl within 20 seconds of a cache_drain could yield negative "USED"
counts.

Also, grab the uma_mtx while in the sysctl handler.  This hadn't caused
problems yet because Giant is held all the time.

Reported by:	kkenn
2002-03-24 10:56:11 +00:00
Jeff Roberson
736ee5907f Add uma_zone_set_max() to add enforced limits to non vm obj backed zones. 2002-03-20 05:28:34 +00:00
Jeff Roberson
8355f576a9 This is the first part of the new kernel memory allocator. This replaces
malloc(9) and vm_zone with a slab like allocator.

Reviewed by:	arch@
2002-03-19 09:11:49 +00:00