Always use snprintf()'s return value, since discarding it is a style
bug at best and using it here gives slightly simpler code and better
error checking. Use snprintf() in putlongdouble() the same as in
putfloat(). (1.25 changed most sprintf()'s to snprintf()'s to fix
non-bugs without changing the logic to use the result of snprintf();
1.27 restored one of the sprintf()s by cloning a stale version of
putfloat().)
Don't print a too-long field in the unlikely case that the fallback
to M units in putint() leaves the field still too long. (The fallback
to printing stars was lost in rev.1.58 when the fallback to M units
was added.)
cannot run into other fields or field descriptors. If the value is
too large to fit in the field width, then the output format is adjusted
so that the value (usually) fits, but with fields running together
externally this adjustment usually didn't help. Mostly it doesn't
matter to lose 1 digit of precision, but switching the output format
is bad if it happens often or gives bogus units. The loss of width
is most serious for fields near "Csw" (which are also the ones which
must often ran together) since these have a high variance and large
values relative to the possible field widths so the switch occurs more
often now, and for the memory size fields where the switch gives the
bogus units kKB or MKB.
Now only the fields for r, p, d, s and w can run into each other.
These fields have width 3, and 3 cannot be reduced to 2 without losing
all precision when the value is between 100 and 999.
Trim "pdwake" to "pdwak" at think time now that it doesn't get clobbered
at runtime. The manpage doesn't need to be changed for this because
it documents the clobbered descriptor, unlike for 4 other too-long
descriptors which only get clobbered if there are lots of interrupt
sources.
Trim "% busy" to "%busy" since most other descriptors for percentages
are spelled without the space and this change makes changing the widths
of the %busy fields unnecessary.
around PUTRATE() because PUTRATE() only looked like a function -- it was
multiple statements. Use "do {...} while(0)" as usual in PUTRATE() so
that it is a single statement that can be used like a function.
large. In most cases it is still 1 too large, so fields tend to run
together, but in the following cases it was more than 1 too large, and
the starting column was too small too, so the field started inside the
previous field or descriptor and clobbered that:
- "wire": the number for this overwrote 2 characters of the number for
"Flt". Reduce the field width by 3 (2 to avoid the overwrite and 1
so that the fields don't run together). This was already done for
the preceding number for "cow".
- "inact": the number for this overwrote 1 character of the descriptor
"Idle". Reducing the field width by 2 is enough.
- "cache:" the number for this overwrote 3 characters of the scale
"...| |". The field width should be reduced by 4 to keep things
from running together, but that is a lot and not so necessary here
since the final "|" in the scale serves as a delimiter. Only reduce
it by 3.
- "free": the number for this overwrote 2 characters of the bar graph.
The character position under the final "|" in the scale is apparently
not used, so reducing the field width by 3 is enough.
When "zfod" is in the main vmstat display:
- use the normal field width of 9 (not 5) for it since there is no shortage
of space. Fix style bugs (excessive {}) in the statement that
conditionally writes it.
Write all reduced field widths for vmstat fields as "9 - <reduction>" as
a hint that we don't want to reduce them.
number in more cases by stealing 2 characters from the count field to
give more space in the descriptor field, but it did the column adjustments
for this strangely using an off-by-2 error in the base column and
compensating off-by-2 errors in 6 offsets from the base column (4 new
errors and 2 from not changing the offsets that actually changed).
Print the "Interrupts" header directly at its offset from the base column
instead of spacing it half using the offset and half by printing a space
character.
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)
<netinet/tcp_var.h>'s prerequisites. Prerequistes should not grow for
userland headers, and <netinet/tcp_var.h> is unfortunately still needed
in userland.
where MB/s and tps statistics would always be zero, presumably because
they were being averaged out over the time between now and when the
system booted instead of a few seconds.
PR: 58683
Kernel:
Change statistics to use the *uptime() timescale (ie: relative to
boottime) rather than the UTC aligned timescale. This makes the
device statistics code oblivious to clock steps.
Change timestamps to bintime format, they are cheaper.
Remove the "busy_count", and replace it with two counter fields:
"start_count" and "end_count", which are updated in the down and
up paths respectively. This removes the locking constraint on
devstat.
Add a timestamp argument to devstat_start_transaction(), this will
normally be a timestamp set by the *_bio() function in bp->bio_t0.
Use this field to calculate duration of I/O operations.
Add two timestamp arguments to devstat_end_transaction(), one is
the current time, a NULL pointer means "take timestamp yourself",
the other is the timestamp of when this transaction started (see
above).
Change calculation of busy_time to operate on "the salami principle":
Only when we are idle, which we can determine by the start+end
counts being identical, do we update the "busy_from" field in the
down path. In the up path we accumulate the timeslice in busy_time
and update busy_from.
Change the byte_* and num_* fields into two arrays: bytes[] and
operations[].
Userland:
Change the misleading "busy_time" name to be called "snap_time" and
make the time long double since that is what most users need anyway,
fill it using clock_gettime(CLOCK_MONOTONIC) to put it on the same
timescale as the kernel fields.
Change devstat_compute_etime() to operate on struct bintime.
Remove the version 2 legacy interface: the change to bintime makes
compatibility far too expensive.
Fix a bug in systat's "vm" page where boot relative busy times would
be bogus.
Bump __FreeBSD_version to 500107
Review & Collaboration by: ken
ifstat Display the network traffic going through active interfaces
on the system. Idle interfaces will not be displayed until
they receive some traffic.
For each interface being displayed, the current, peak and
total statistics are displayed for incoming and outgoing
traffic. By default, the ifstat display will automatically
scale the units being used so that they are in a human-read-
able format. The scaling units used for the current and peak
traffic columns can be altered by the scale command.
Submitted by: Trent Nelson <trent@arpa.com>
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.
when I changed the allocator bits. This implements per-CPU mbtypes
stats by keeping net number of decrements/increments of a given mbtype
per-CPU and then summing all of the per-CPU mbtypes to produce the total
net number of allocated mbufs of the given mbtype.
Counters are carefully balanced to avoid/prevent underflows/overflows.
mbtypes stats are re-enabled with the idea that we may occasionally
(although very rarely) observe slight inconsistencies in the stat
reporting. Most of the time, we should be fine, though.
Also make appropriate modifications to netstat(1) and systat(1) to do
the necessary reporting.
Submitted by: Jiangyi Liu <jyliu@163.net>
were indices in a dense array. The cpuids are a sparse set and treat
them as such, setting up containers only for CPUs activated during
mb_init().
- Fix netstat(1) and systat(1) to treat the per-CPU stats area as a sparse
map, in accordance with the above.
This allows us to properly boot with certain CPUs disactivated. However, if
we later decide to re-activate said CPUs, we will barf until we decide to
implement CPU spinon/spinoff callback hooks to allow for said CPUs' per-CPU
containers to get configured on their activation.
Reported by: mjacob
Partially (sys/ diffs) Submitted by: mjacob
introduce a modified allocation mechanism for mbufs and mbuf clusters; one
which can scale under SMP and which offers the possibility of resource
reclamation to be implemented in the future. Notable advantages:
o Reduce contention for SMP by offering per-CPU pools and locks.
o Better use of data cache due to per-CPU pools.
o Much less code cache pollution due to excessively large allocation macros.
o Framework for `grouping' objects from same page together so as to be able
to possibly free wired-down pages back to the system if they are no longer
needed by the network stacks.
Additional things changed with this addition:
- Moved some mbuf specific declarations and initializations from
sys/conf/param.c into mbuf-specific code where they belong.
- m_getclr() has been renamed to m_get_clrd() because the old name is really
confusing. m_getclr() HAS been preserved though and is defined to the new
name. No tree sweep has been done "to change the interface," as the old
name will continue to be supported and is not depracated. The change was
merely done because m_getclr() sounds too much like "m_get a cluster."
- TEMPORARILY disabled mbtypes statistics displaying in netstat(1) and
systat(1) (see TODO below).
- Fixed systat(1) to display number of "free mbufs" based on new per-CPU
stat structures.
- Fixed netstat(1) to display new per-CPU stats based on sysctl-exported
per-CPU stat structures. All infos are fetched via sysctl.
TODO (in order of priority):
- Re-enable mbtypes statistics in both netstat(1) and systat(1) after
introducing an SMP friendly way to collect the mbtypes stats under the
already introduced per-CPU locks (i.e. hopefully don't use atomic() - it
seems too costly for a mere stat update, especially when other locks are
already present).
- Optionally have systat(1) display not only "total free mbufs" but also
"total free mbufs per CPU pool."
- Fix minor length-fetching issues in netstat(1) related to recently
re-enabled option to read mbuf stats from a core file.
- Move reference counters at least for mbuf clusters into an unused portion
of the cluster itself, to save space and need to allocate a counter.
- Look into introducing resource freeing possibly from a kproc.
Reviewed by (in parts): jlemon, jake, silby, terry
Tested by: jlemon (Intel & Alpha), mjacob (Intel & Alpha)
Preliminary performance measurements: jlemon (and me, obviously)
URL: http://people.freebsd.org/~bmilekic/mb_alloc/
and compiler warnings.
The data for network statistics are still obtained via the kvm interface
if systat was started with the needed privileges, otherwise sysctls are
used. The reason for this is that with really many open sockets, the
sysctl method is probably slower, but it systat -netstat is probably not
really usable in either mode under these conditions.
Approved by: rwatson
base system, but not in BruceBSD.
o Fix up style violations of various sorts.
o Remove redundant normalization of hertz variable, as the sysctl handler
does this work (unlike when kread was used).
Submitted by: bde
no longer contains kernel specific data structures, but rather
only scalar values and structures that are already part of the
kernel/user interface, specifically rusage and rtprio. It no
longer contains proc, session, pcred, ucred, procsig, vmspace,
pstats, mtx, sigiolst, klist, callout, pasleep, or mdproc. If
any of these changed in size, ps, w, fstat, gcore, systat, and
top would all stop working. The new structure has over 200 bytes
of unassigned space for future values to be added, yet is nearly
100 bytes smaller per entry than the structure that it replaced.
and numvnodes are longs in the kernel. They should remain longs in systat,
what really needs to change is that they should be using SYSCTL_LONG rather
than SYSCTL_INT. I also changed wantfreevnodes to SYSCTL_LONG because I
happened to notice it.
I wish there was a way to find all of these automatically..
Pointed out by: bde
maxvnodes, numvnodes, freevnodes, nchstats, and numdirtybuffers.
o Make the hw.ncpu error checking code a little more rigorous by
sanity checking the returned data size.
o Didn't fix machine-dependent non-sysctl-exported variables:
intrnames, eintrnames, intrcnt, eintrcnt, as these variables are
defined and exported from machine-dependent kernel code in
assembly. This should probably be fixed somehow.
structure member that doesn't exist anymore.
Use getsysctlbyname for kern.ipc.mbstat instead of sysctl.
Use netstat's method of displaying values from mtnames.
Submitted by: Ian Dowse <iedowse@maths.tcd.ie>
Missed by PR: 19809
