- Initialize mbpool and mclpool with msize and mclbytes, respectively,
so that those values may be patched and have an actual affect on the
next system reboot.
- Set low water marks on mbpool (default: 16) and mclpool (default: 8).
This should be of great help for diskless systems, which need to allocate
mbufs in order to clean dirty pages; the low water marks increase the
chances of this being possible to do in memory starvation situations.
- Add support for getting/setting some mbuf-related parameters via sysctl.
* msize and mclsize (read-only)
* nmbclusters (read-only unless the platform has direct-mapped pool pages,
in which case the value can be increased).
* mblowat and mcllowat (read/write)
NMBCLUSTERS for the mbuf cluster pool. On platforms which use direct-mapped
segments for pool pages (MIPS and Alpha), this makes NMBCLUSTERS actually
meaningful (such ports don't even allocate mb_map, as it is not used to
map mbuf cluster pages).
Improve the message logged at a maximum rate of once per second. The
new message: "WARNING: mclpool limit reached; increase NMBCLUSTERS".
In the back-end pool page allocator, remove the message about mb_map
being full. The message was not necessarily correct as the allocator
may have been starved for pages, rather than for space in the map. Also,
the hard limit on the mbuf cluster pool will be reached before the map
fills (the last cluster will always fit into the map), so the message
is redundant.
Add a comment in mbinit() about considering setting low water marks on
the mbuf and mbuf cluster pools.
date: 1998/08/01 01:47:24; author: thorpej; state: Exp; lines: +18 -8
Don't call the protocol drain routines if how == M_NOWAIT, which typically
means we're in interrupt context. Since we can be called from a network
hardware interrupt, we could corrupt the protocol queues we try to drain
them at that time.
The problem has been addressed by letting the drain'able protocols use
a locking scheme to prevent queue corruption.
means we're in interrupt context. Since we can be called from a network
hardware interrupt, we could corrupt the protocol queues we try to drain
them at that time.
UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.
this is the rest of the MI portion changes.
this will be KNF'd shortly. :-)
external storage. Highlights:
- additional "void *" argument to (*ext_free)(), an opaque
cookie for use by the free function.
- MCLALLOC() and MCLFREE() calls are gone. They are replaced
by MEXTADD() (add external storage to mbuf), MEXTMALLOC()
(malloc() external storage and attach to mbuf), and
MEXTREMOVE() (remove external storage from mbuf).
- completely new external storage reference counting
mechanism; mclrefcnt[] is gone.
These changes will eventually be used to pass driver DMA buffers up
the network stack, and reduce/eliminate copies in certain code paths
(e.g. NFS writes).
From Matt Thomas <matt@3am-software.com> and myself <thorpej@nas.nasa.gov>,
with some input from Chris Demetriou <cgd@cs.cmu.edu> and review by
Charles Hannum <mycroft@mit.edu>.
and free some space by calling m_reclaim(). Also, log the "mb_map full"
error message (at most) every 60-seconds. The old code would log it
once over the lifetime of the system, but that's not a useful diagnostic.
(More useful is the new behaviour, which roughly indicates how often
periods of heavy load occur, without spamming the console and system
logs with messages.)
