Commit Graph

38 Commits

Author SHA1 Message Date
Lawrence Stewart
1c6cae9711 Change uma_zone_set_max to return the effective value of "nitems" after
rounding. The same value can also be obtained with uma_zone_get_max, but this
change avoids a caller having to make two back-to-back calls.

Sponsored by:	FreeBSD Foundation
Reviewed by:	gnn, jhb
2010-10-16 04:41:45 +00:00
Lawrence Stewart
c4ae7908a7 - Simplify implementation of uma_zone_get_max.
- Add uma_zone_get_cur which returns the current approximate occupancy of
  a zone. This is useful for providing stats via sysctl amongst other things.

Sponsored by:	FreeBSD Foundation
Reviewed by:	gnn, jhb
MFC after:	2 weeks
2010-10-16 04:14:45 +00:00
Andre Oppermann
e49471b04b Add uma_zone_get_max() to obtain the effective limit after a call
to uma_zone_set_max().

The UMA zone limit is not exactly set to the value supplied but
rounded up to completely fill the backing store increment (a page
normally).  This can lead to surprising situations where the number
of elements allocated from UMA is higher than the supplied limit
value.  The new get function reads back the effective value so that
the supplied limit value can be adjusted to the real limit.

Reviewed by:	jeffr
MFC after:	1 week
2010-08-16 14:24:00 +00:00
Sean Bruno
bf96595915 Add a new column to the output of vmstat -z to indicate the number
of times the system was forced to sleep when requesting a new allocation.

Expand the debugger hook, db_show_uma, to display these results as well.

This has proven to be very useful in out of memory situations when
it is not known why systems have become sluggish or fail in odd ways.

Reviewed by:	rwatson alc
Approved by:	scottl (mentor) peter
Obtained from:	Yahoo Inc.
2010-06-15 19:28:37 +00:00
Jeff Roberson
e20a199fd5 - Make the keg abstraction more complete. Permit a zone to have multiple
backend kegs so it may source compatible memory from multiple backends.
   This is useful for cases such as NUMA or different layouts for the same
   memory type.
 - Provide a new api for adding new backend kegs to secondary zones.
 - Provide a new flag for adjusting the layout of zones to stagger
   allocations better across cache lines.

Sponsored by:	Nokia
2009-01-25 09:11:24 +00:00
Giorgos Keramidas
2db63c5e38 Various comment nits, and typos. 2008-11-02 00:41:26 +00:00
Alan Cox
7630c26507 Reintroduce UMA_SLAB_KMAP; however, change its spelling to
UMA_SLAB_KERNEL for consistency with its sibling UMA_SLAB_KMEM.
(UMA_SLAB_KMAP met its original demise in revision 1.30 of
vm/uma_core.c.)  UMA_SLAB_KERNEL is now required by the jumbo frame
allocators.  Without it, UMA cannot correctly return pages from the
jumbo frame zones to the VM system because it resets the pages' object
field to NULL instead of the kernel object.  In more detail, the jumbo
frame zones are created with the option UMA_ZONE_REFCNT.  This causes
UMA to overwrite the pages' object field with the address of the slab.
However, when UMA wants to release these pages, it doesn't know how to
restore the object field, so it sets it to NULL.  This change teaches
UMA how to reset the object field to the kernel object.

Crashes reported by: kris
Fix tested by: kris
Fix discussed with: jeff
MFC after: 6 weeks
2008-04-04 18:41:12 +00:00
Robert Watson
1e319f6db3 Add uma_set_align() interface, which will be called at most once during
boot by MD code to indicated detected alignment preference.  Rather than
cache alignment being encoded in UMA consumers by defining a global
alignment value of (16 - 1) in UMA_ALIGN_CACHE, UMA_ALIGN_CACHE is now
a special value (-1) that causes UMA to look at registered alignment.  If
no preferred alignment has been selected by MD code, a default alignment
of (16 - 1) will be used.

Currently, no hardware platforms specify alignment; architecture
maintainers will need to modify MD startup code to specify an alignment
if desired.  This must occur before initialization of UMA so that all UMA
zones pick up the requested alignment.

Reviewed by:	jeff, alc
Submitted by:	attilio
2007-02-11 20:13:52 +00:00
Mohan Srinivasan
6c125b8df6 Fix for problems that occur when all mbuf clusters migrate to the mbuf packet
zone. Cluster allocations fail when this happens. Also processes that may have
blocked on cluster allocations will never be woken up. Thanks to rwatson for
an overview of the issue and pointers to the mbuma paper and his tool to dump
out UMA zones.

Reviewed by: andre@
2007-01-25 01:05:23 +00:00
John Baldwin
663b416f16 - Add a new function uma_zone_exhausted() to see if a zone is full.
- Add a printf in swp_pager_meta_build() to warn if the swapzone becomes
  exhausted so that there's at least a warning before a box that runs out
  of swapzone space before running out of swap space deadlocks.

MFC after:	1 week
Reviwed by:	alc
2007-01-05 19:09:01 +00:00
Dag-Erling Smørgrav
3803b26bae As alc pointed out to me, vm_page.c 1.305 was incomplete: uma_startup()
still uses the constant UMA_BOOT_PAGES.  Change it to accept boot_pages
as an additional argument.

MFC after:	2 weeks
2005-10-08 21:03:54 +00:00
Robert Watson
cbbb4a0089 Rename UMA_MAX_NAME to UTH_MAX_NAME, since it's a maximum in the
monitoring API, which might or might not be the same as the internal
maximum (currently none).

Export flag information on UMA zones -- in particular, whether or
not this is a secondary zone, and so the keg free count should be
considered in that light.

MFC after:	1 day
2005-07-25 00:47:32 +00:00
Robert Watson
08ecce74bc Improve canonicalization of copyrights. Order copyrights by order of
assertion (jeff, bmilekic, rwatson).

Suggested ages ago by:	bde
MFC after:		1 week
2005-07-16 09:51:52 +00:00
Mike Silbersack
2018f30c01 Increase the flags field for kegs from a 16 to a 32 bit value;
we have exhausted all 16 flags.
2005-07-16 02:23:41 +00:00
Robert Watson
2019094a35 Track UMA(9) allocation failures by zone, and export via sysctl.
Requested by:	victor cruceru <victor dot cruceru at gmail dot com>
MFC after:	1 week
2005-07-15 23:34:39 +00:00
Robert Watson
7a52a97eb3 Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator
statistics via a binary structure stream:

- Add structure 'uma_stream_header', which defines a stream version,
  definition of MAXCPUs used in the stream, and the number of zone
  records in the stream.

- Add structure 'uma_type_header', which defines the name, alignment,
  size, resource allocation limits, current pages allocated, preferred
  bucket size, and central zone + keg statistics.

- Add structure 'uma_percpu_stat', which, for each per-CPU cache,
  includes the number of allocations and frees, as well as the number
  of free items in the cache.

- When the sysctl is queried, return a stream header, followed by a
  series of type descriptions, each consisting of a type header
  followed by a series of MAXCPUs uma_percpu_stat structures holding
  per-CPU allocation information.  Typical values of MAXCPU will be
  1 (UP compiled kernel) and 16 (SMP compiled kernel).

This query mechanism allows user space monitoring tools to extract
memory allocation statistics in a machine-readable form, and to do so
at a per-CPU granularity, allowing monitoring of allocation patterns
across CPUs in order to better understand the distribution of work and
memory flow over multiple CPUs.

While here, also export the number of UMA zones as a sysctl
vm.uma_count, in order to assist in sizing user swpace buffers to
receive the stream.

A follow-up commit of libmemstat(3), a library to monitor kernel memory
allocation, will occur in the next few days.  This change directly
supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats
rather than separately maintained mbuf allocator statistics.

MFC after:	1 week
2005-07-14 16:35:13 +00:00
Bosko Milekic
8076cb5289 Well, it seems that I pre-maturely removed the "All rights reserved"
statement from some files, so re-add it for the moment, until the
related legalese is sorted out.  This change affects:

sys/kern/kern_mbuf.c
sys/vm/memguard.c
sys/vm/memguard.h
sys/vm/uma.h
sys/vm/uma_core.c
sys/vm/uma_dbg.c
sys/vm/uma_dbg.h
sys/vm/uma_int.h
2005-02-16 21:45:59 +00:00
Warner Losh
60727d8b86 /* -> /*- for license, minor formatting changes 2005-01-07 02:29:27 +00:00
Bosko Milekic
7b8712053c Add my copyright and update Jeff's copyright on UMA source files,
as per his request.

Discussed with: Jeffrey Roberson
2004-12-26 00:35:12 +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
b83e441b9f Fix a comment above uma_zsecond_create(), describing its arguments.
It doesn't take 'align' and 'flags' but 'master' instead, which is
a reference to the Master Zone, containing the backing Keg.

Pointed out by: Tim Robbins (tjr)
2004-06-01 01:36:26 +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
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
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +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
Sheldon Hearn
29b4d52653 Fix typo in comments (misspelled "necessary"). 2002-10-22 12:10:27 +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
Mark Murray
f6e34b823a Void functions cannot return values. 2002-07-18 15:53:11 +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
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
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
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
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
c235bfa551 Spelling correction; s/seperate/separate/g
Submitted by:	eric
2002-04-07 22:56:48 +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