allow changes to the filesystem's write_behind behavior. By the
default the filesystem aggressively issues write_behind's. Three values
may be specified for vfs.write_behind. 0 disables write_behind, 1 results
in historical operation (agressive write_behind), and 2 is an experimental
backed-off write_behind. The values of 0 and 1 are recommended. The value
of 0 is recommended in conjuction with an increase in the number of
NBUF's and the number of dirty buffers allowed (vfs.{lo,hi}dirtybuffers).
Note that a value of 0 will radically increase the dirty buffer load on
the system. Future work on write_behind behavior will use values 2 and
greater for testing purposes.
Submitted by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: Kirk McKusick <mckusick@mckusick.com>
QUEUE_AGE, QUEUE_LRU, and QUEUE_EMPTY we instead have QUEUE_CLEAN,
QUEUE_DIRTY, QUEUE_EMPTY, and QUEUE_EMPTYKVA. With this patch clean
and dirty buffers have been separated. Empty buffers with KVM
assignments have been separated from truely empty buffers. getnewbuf()
has been rewritten and now operates in a 100% optimal fashion. That is,
it is able to find precisely the right kind of buffer it needs to
allocate a new buffer, defragment KVM, or to free-up an existing buffer
when the buffer cache is full (which is a steady-state situation for
the buffer cache).
Buffer flushing has been reorganized. Previously buffers were flushed
in the context of whatever process hit the conditions forcing buffer
flushing to occur. This resulted in processes blocking on conditions
unrelated to what they were doing. This also resulted in inappropriate
VFS stacking chains due to multiple processes getting stuck trying to
flush dirty buffers or due to a single process getting into a situation
where it might attempt to flush buffers recursively - a situation that
was only partially fixed in prior commits. We have added a new daemon
called the buf_daemon which is responsible for flushing dirty buffers
when the number of dirty buffers exceeds the vfs.hidirtybuffers limit.
This daemon attempts to dynamically adjust the rate at which dirty buffers
are flushed such that getnewbuf() calls (almost) never block.
The number of nbufs and amount of buffer space is now scaled past the
8MB limit that was previously imposed for systems with over 64MB of
memory, and the vfs.{lo,hi}dirtybuffers limits have been relaxed
somewhat. The number of physical buffers has been increased with the
intention that we will manage physical I/O differently in the future.
reassignbuf previously attempted to keep the dirtyblkhd list sorted which
could result in non-deterministic operation under certain conditions,
such as when a large number of dirty buffers are being managed. This
algorithm has been changed. reassignbuf now keeps buffers locally sorted
if it can do so cheaply, and otherwise gives up and adds buffers to
the head of the dirtyblkhd list. The new algorithm is deterministic but
not perfect. The new algorithm greatly reduces problems that previously
occured when write_behind was turned off in the system.
The P_FLSINPROG proc->p_flag bit has been replaced by the more descriptive
P_BUFEXHAUST bit. This bit allows processes working with filesystem
buffers to use available emergency reserves. Normal processes do not set
this bit and are not allowed to dig into emergency reserves. The purpose
of this bit is to avoid low-memory deadlocks.
A small race condition was fixed in getpbuf() in vm/vm_pager.c.
Submitted by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: Kirk McKusick <mckusick@mckusick.com>
zero traps. I actually can't believe that this compiler is *sooooo* stupid
that it did a divide when there was 1024L*1024L instead of a right shift by
20. When we get quad type modifiers in kernel printf we can change to this
too (to avoid overflow on > terabyte disk sizes).
behavior slightly.
If machine/bus.h is included, but neither bus_memio.h nor bus_pio.h
are included, then behave as if both were included.
This won't change existing drivers, all of which include one or more
of bus_{p,mem}io.h, but will allow drivers from other systems to come
over with fewer changes. I freely admit that this might not be
optimal for some drivers, but those drivers can be optimized for
FreeBSD after the initial bringup happens.
Without the change, there is a bug that preclude drivers from
compiling with strange warning/errors.
I've been running this here for a while now w/o ill effects.
Reviewed by: gibbs
Not objected to by: bde, arch@ list.
On the VAX, it used to be used for special compilation to avoid the
optimizer which would mess with memory mapped devices etc. These days
we use 'volatile'.
EGCS assign weak symbols to inline functions it couldn't inline (e.g. virtual
inline functions), template functions, etc. Omitting them result in quite bogus
profile.
Weak symbols created by __weak_reference are not really problem.
Caught by: Ilya Segalovich <iseg@comptek.ru>
Change definition of sflag
Reported-by: Johan Karlsson <k@numeri.campus.luth.se>
Doug <Doug@gorean.org>
green
World-broken-by: grog
Pointy-hat-passed-to: grog
isp_io_map, isp_no_fwload, isp_fwload, isp_no_nvram, isp_fcduplex
which are all bitmaps of isp instances that should or shouldn't
map memory space, I/O space, not load f/w, load f/w, ignore nvram,
not ignore nvarm, set full duplex mode. Also have an isp_seed value
that we can use to generate a pseudo seed for a synthetic WWN.
Other minor cosmetic cleanup. Add in support for the Qlogic ISP
2200. Very important change where we actually check now to see
whether we were successful in mapping request and response queues
(and fibre channel scratch space).
not having SCSI_ISP_SCCLUN config defined if we don't have f/w for
the 2200- it's resident firmware uses SCCLUN (65535 luns)). Change
the way the default LoopID is gathered (it's now a platform specific
define so that some attempt at a synthetic WWN can be made in case
NVRAM isn't readable).
Change initialization of options a bit- don't use ADISC. Set
FullDuplex mode if config options tells us to do so. Do not use
FULL_LOGIN after LIP- it's the right thing to do but it causes too
much loop disruption (Loop Resets). Sanity check some default
values. Redo construction of port and node WWNs based upon what we
have- if we have 2 in the top nibble, we can have distinct port
and node WWNs. Clean up some SCCLUN related code that we obviously
had never compiled (:-(). Audit commands coming int ispscsicmd and
don't throw commands at Fibre devices that do not have Class 3
service parameters TARGET ROLE defined.
Clean up f/w initialization a bit. Add Fabric support (or at least
the first blush of it). Whew - way too much to describe here.
Basically, after a LIP, hang out until we see a Loop Up or a Port
DataBase Change async event, then see if we're on a Fabric
(GET_PORT_NAME of FL_PORT_ID). If we are, try and scan the fabric
controller for fabric devices using the GetAllNext SNS subcommand.
As we find devices, announce them to the outer layer. Try and do
some guard code for broken (Brocade) SNS servers (that get stuck
in loops- gotta maybe do this a different way using the GP_ID3 cmd
instead). Then do a scan of the lower (local loop) ids using a
GET_PORT_NAME to see if the f/w has logged into anything at that
loop id. If so, then do a GET_PORT_DATABASE command. Do this scan
into a local database. At this point we can say the loop is 'Ready'.
After this, we merge our local loop port database with our stored
port database- in a as yet to be really fully exercised fashion we
try and follow the logic of something having moved around. The
first time we see something at a Loop ID, we fix it, for the purpose
of this system instance, at that Loop ID. If things shift around
so it ends up somewhere else, we still keep it at this Loop ID (our
'Target') but use the new (moved) Loop ID when we actually throw
commands at it. Check for insane cases of different Loop IDs both
claiming to have the same WWN- if that happens, invalidate both.
Notify the outer layer of devices that have arrived and devices
that have gone away. *Finally*, when this is done, search the
softc's database of Fabric devices and perform logout/login actions.
The Qlogic f/w maintains logout/login for all local loop devices.
We have to maintain logout/login for fabric devices- total PITA.
Expect to see this area undergo more change over time.
Change some fcp parameter structures such that we can get the portid
(24 bit value), get both node and port WWN, know whether we're on a fabric
or not, note whether we've ever seen the loop up, and note the current
state of the loop.
Replace the isp_pdb_t structure in fcparams with a reduced cost structure
that maintains a static relationship to 'Target', but can have the actual
loop ID used change (in case, post LIP, we discover things have moved
around). This also retains portid and node/port WWNs. This array gets
larger if we have fabric support compiled in.
Note special loop IDs that are invariate for this device- FL_PORT_ID
(0x7e) which tells us if there's a fabric controller present, FC_PORT_ID
and FC_SNS_ID (fabric controller port and fabric SNS server port). We don't
use the latter two for anything. IDs above FC_SNS_ID up through 255 are
available for mapping fabric devices to 'target' ids.
Add in a config define to set FC full duplex mode. Add in a define to
recognize the Qlogic 2200 boards. Add comments about ISPCTL commands.
Add and change some ISPASYNC enumes.
