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)
- 0 should have been -1 in previous commit (just to stay consistent),
- Spell null pointers as NULL, not 0,
- Fixed the comment about pr_usesysctl to not confuse it with boolean.
Pointed by: bde
calculations. Long longs should never be used, since they break compiling
with C90 compilers and don't necessarily work any better than longs for
avoiding overflow.
Print percentages with another digit of precision since they can be small
and this is easy to do now that the format is floating point.
Restored some more of the old -m output:
Print the percentage of allocated memory that is in use. This is the
amount of memory in active mbufs and mbuf clusters relative to the
total amount of memory soft-allocated for mbufs and mbuf clusters.
Print the percentage of allocated memory that is wired (cached). The
old mbuf allocator never freed memory so printing this value wasn't
useful. A previous version of netstat for the new allocator printed
the in-use amount as a percentage of the wired amount.
Fixed some nearby style bugs (excessive parenthesization and a redundant
return).
Reviewed by: alfred
printf format warnings for inet6.c (pluralies() was implicit int, but
the context requires a "char *").
Added WARNS?=2 to the Makefile so that such errors don't come back.
Added NO_WERROR?= to the Makefile because I haven't checked that setting
WARNS doesn't uncover more bugs except on i386's.
overflow was breaking a bunch of the stats, specifically the
percentage displayed for wired memory.
Fix the output for current/peak/max lines, I forgot to output the types.
161/320/51200 (current/peak/max):
-to-
639/25696/51200 mbufs in use (current/peak/max):
using the old 'cached' value but reporting it as 'cached'.
I've decided to report the 'cached' as 'peak', why? Well because
it is the peak, the peak of what is actually allocated. 'cached'
doesn't make sense to me as a user.
truncated. In environments where many tunnel or vlan interfaces are created,
interface names have high numbers which overflow the field width.
PRs: bin/52349, bin/35838
Submitted by: Mike Tancsa, Scot W. Hetzel
Approved by: re (rwatson)
if_xname, if_dname, and if_dunit. if_xname is the name of the interface
and if_dname/unit are the driver name and instance.
This change paves the way for interface renaming and enhanced pseudo
device creation and configuration symantics.
Approved By: re (in principle)
Reviewed By: njl, imp
Tested On: i386, amd64, sparc64
Obtained From: NetBSD (if_xname)
netstat -s -p pim
2. Print information about the bandwidth meters installed in the kernel with
netstat -g
Submitted by: Pavlin Radoslavov <pavlin@icir.org>
multicast VIF tables.
This change is needed for consistency with the rest of the
netstat/mroute.c implementation, and because in some
cases "netstat -g" may fail to report the multicast forwarding
information (e.g., if we run a multicast router on PicoBSD).
* Remove "DVMRP" from the head comment of file netstat/mroute.c,
because the printed multicast-related statistics are not
DVMRP-specific anymore.
Submitted by: Pavlin Radoslavov <pavlin@icir.org>
The -l option is deprecated (hence undocumented in usage() and
SYNOPSIS), as was threatened in the commitlog accompanying rev.
1.10 of main.c.
Approved by: re (blanket)
netstat(1) not display it for now because its effects are not yet
completely implemented and we're about to cut 5.2-RELEASE.
This is temporary.
Approved by: re (scottl, rwatson)
(See: ftp://ftp.rfc-editor.org/in-notes/rfc3514.txt)
This fulfills the host requirements for userland support by
way of the setsockopt() IP_EVIL_INTENT message.
There are three sysctl tunables provided to govern system behavior.
net.inet.ip.rfc3514:
Enables support for rfc3514. As this is an
Informational RFC and support is not yet widespread
this option is disabled by default.
net.inet.ip.hear_no_evil
If set the host will discard all received evil packets.
net.inet.ip.speak_no_evil
If set the host will discard all transmitted evil packets.
The IP statistics counter 'ips_evil' (available via 'netstat') provides
information on the number of 'evil' packets recieved.
For reference, the '-E' option to 'ping' has been provided to demonstrate
and test the implementation.
compile-time constants). That is, a "bucket" now is not necessarily
a page-worth of mbufs or clusters, but it is MBUF_BUCK_SZ, CLUS_BUCK_SZ
worth of mbufs, clusters.
o Rename {mbuf,clust}_limit to {mbuf,clust}_hiwm and introduce
{mbuf,clust}_lowm, which currently has no effect but will be used
to set the low watermarks.
o Fix netstat so that it can deal with the differently-sized buckets
and teach it about the low watermarks too.
o Make sure the per-cpu stats for an absent CPU has mb_active set to 0,
explicitly.
o Get rid of the allocate refcounts from mbuf map mess. Instead,
just malloc() the refcounts in one shot from mbuf_init()
o Clean up / update comments in subr_mbuf.c
1) Include arpa/inet.h for ntohs.
2) Constness fixes.
3) Fix shadowing except for "sin" which shouldn't be in scope.
4) Remove register keyword.
5) Add missing initialsers to user defined structs.
5) Make prototype of netname6 globally visable.
6) Use right macros for printing syncache stats (even though entrie isn't
a word).
non-default but reasonable values of hz this member overflowed,
breaking NFS over UDP.
Also, as long as I'm plowing up struct sockbuf ... Change certain
members from u_long/long to u_int/int in order to reduce wasted
space on 64-bit machines. This change was requested by Andrew
Gallatin.
Netstat and systat need to be rebuilt. I am incrementing
__FreeBSD_version in case any ports need to change.
supplied rather than arbitrarily larger widths. This (almost) guarantees
that no columns will be truncated (routing table additions between the
width calculation and display passes may create a row with column widths
larger than those calculated).
Sponsored by: NTT Multimedia Communications Labs
