When a file is first being written, the dynamic block reallocation
(implemented by ext2_reallocblks) relocates the file's blocks
so as to cluster them together into a contiguous set of blocks on
the disk.
When the cluster crosses the boundary into the first indirect block,
the first indirect block is initially allocated in a position
immediately following the last direct block. Block reallocation
would usually destroy locality by moving the indirect block out of
the way to keep the data blocks contiguous.
The issue was diagnosed long ago by Bruce Evans on ffs and surfaced
on ext2fs when block reallocaton was ported. This is only a partial
solution based on the similarities with FFS. We still require more
review of the allocation details that vary in ext2fs.
Reported by: bde
MFC after: 1 week
Rick Macklem and I discussed the default number of nfsd threads and
concluded that it is too low to perform adiquitely on today's hardware.
We decided to auto tune the number of nfsds based on the number of cpus
in the system.
While I'm here I've also added:
1) ability to set the minthreads/maxthreads from userland.
2) ability to run nfsd in debug mode via the cli.
Reviewed by: rmacklem
MFC after: 2 weeks
which was to self-initialize during the first function-call. This didn't work
so well because the first call was may or may-not be within a sub-shell
(which prevented proper setup of the pass-thru file descriptor, resulting in
dialogs that would not display).
Approved by: adrian (co-mentor) (implicit)
kernel memory, whichever is lower. The overall mbuf related memory
limit must be set so that mbufs (and clusters of various sizes)
can't exhaust physical RAM or KVM.
The limit is set to half of the physical RAM or KVM (whichever is
lower) as the baseline. In any normal scenario we want to leave
at least half of the physmem/kvm for other kernel functions and
userspace to prevent it from swapping too easily. Via a tunable
kern.maxmbufmem the limit can be upped to at most 3/4 of physmem/kvm.
At the same time divorce maxfiles from maxusers and set maxfiles to
physpages / 8 with a floor based on maxusers. This way busy servers
can make use of the significantly increased mbuf limits with a much
larger number of open sockets.
Tidy up ordering in init_param2() and check up on some users of
those values calculated here.
Out of the overall mbuf memory limit 2K clusters and 4K (page size)
clusters to get 1/4 each because these are the most heavily used mbuf
sizes. 2K clusters are used for MTU 1500 ethernet inbound packets.
4K clusters are used whenever possible for sends on sockets and thus
outbound packets. The larger cluster sizes of 9K and 16K are limited
to 1/6 of the overall mbuf memory limit. When jumbo MTU's are used
these large clusters will end up only on the inbound path. They are
not used on outbound, there it's still 4K. Yes, that will stay that
way because otherwise we run into lots of complications in the
stack. And it really isn't a problem, so don't make a scene.
Normal mbufs (256B) weren't limited at all previously. This was
problematic as there are certain places in the kernel that on
allocation failure of clusters try to piece together their packet
from smaller mbufs.
The mbuf limit is the number of all other mbuf sizes together plus
some more to allow for standalone mbufs (ACK for example) and to
send off a copy of a cluster. Unfortunately there isn't a way to
set an overall limit for all mbuf memory together as UMA doesn't
support such a limiting.
NB: Every cluster also has an mbuf associated with it.
Two examples on the revised mbuf sizing limits:
1GB KVM:
512MB limit for mbufs
419,430 mbufs
65,536 2K mbuf clusters
32,768 4K mbuf clusters
9,709 9K mbuf clusters
5,461 16K mbuf clusters
16GB RAM:
8GB limit for mbufs
33,554,432 mbufs
1,048,576 2K mbuf clusters
524,288 4K mbuf clusters
155,344 9K mbuf clusters
87,381 16K mbuf clusters
These defaults should be sufficient for even the most demanding
network loads.
MFC after: 1 month
accept queues a new socket/connection may be added to the queue
due to a race on the ACCEPT_LOCK.
The submitted patch is slightly changed in comments, teardown
and locking order and extended with KASSERT's.
Submitted by: Vijay Singh <vijju.singh-at-gmail-dot-com>
Found by: His team.
MFC after: 1 week
now this works for non-debug and debug builds.
* Add a comment reminding me (or someone) to audit all of the relevant
math to ensure there's no weird wrapping issues still lurking about.
But yes, this does seem to be mostly working.
Pointy-hat-to: adrian, yet again
is in capability mode.
- Add VN_OPEN_NOCAPCHECK flag for vn_open_cred() to will ne converted into
NOCAPCHECK namei flag.
This functionality will be used to enable core dumps for sandboxed processes.
Reviewed by: rwatson
Obtained from: WHEEL Systems
MFC after: 2 weeks
to himself. For example abort(3) at first tries to do kill(getpid(), SIGABRT)
which was failing in capability mode, so the code was failing back to exit(1).
Reviewed by: rwatson
Obtained from: WHEEL Systems
MFC after: 2 weeks
While here, also make the code that enforces power-of-two more
forgiving, instead of just resetting to 512, graciously round-down
to the next lower power of two.
* add some further debugging prints, which are quite nice to have
* add in ALQ hooks (optional!) to allow for the TDMA information to be
logged in-line with the TX and RX descriptor information.
The existing logic wrapped programming nexttbtt at 65535 TU.
This is not good enough for the 11n chips, whose nexttbtt register
(GENERIC_TIMER_0) has an initial value from 0..2^31-1 TSF.
So converting the TU to TSF had the counter wrap at (65535 << 10) TSF.
Once this wrap occured, the nexttbtt value was very very low, much
lower than the current TSF value. At this point, the nexttbtt timer
would constantly fire, leading to the TX queue being constantly gated
open.. and when this occured, the sender was not correctly transmitting
in its slot but just able to continuously transmit. The master would
then delay transmitting its beacon until after the air became free
(which I guess would be after the burst interval, before the next burst
interval would quickly follow) and that big delta in master beacon TX
would start causing big swings in the slot timing adjustment.
With this change, the nexttbtt value is allowed to go all the way up
to the maximum value permissable by the 32 bit representation.
I haven't yet tested it to that point; I really should. The AR5212
HAL now filters out values above 65535 TU for the beacon configuration
(and the relevant legal values for SWBA, DBA and NEXTATIM) and the
AR5416 HAL just dutifully programs in what it should.
With this, TDMA is now useful on the 802.11n chips.
Tested:
* AR5416, AR9280 TDMA slave
* AR5413 TDMA slave
what the maximum legal values are.
The current beacon timer configuration from TDMA wraps things at
HAL_BEACON_PERIOD-1 TU. For the 11a chips this is fine, but for
the 11n chips it's not enough resolution. Since the 11a chips have a
limit on what's "valid", just enforce this so when I do write larger
values in, they get suitably wrapped before programming.
Tested:
* AR5413, TDMA slave
Todo:
* Run it for a (lot) longer on a clear channel, ensure that no strange
slippages occur.
* Re-validate this on STA configurations, just to be sure.
much all the union of all the kernel configuration files, including all
the CPU types, Marvell SOC types and at91 board types. Any device not
supported (read: does not compile) has been removed, which is a fairly
small set actually. As such, LINT gives us very good coverage without
having to build a zillion kernels.
expand to uncompilable code when the kernel configuration contains
"options DEBUG", such as it is for LINT. The toolchain is often a
better approach to figure this out, as it doesn't require one to
boot the kernel.
interfere with structure fields of the same name in drivers, like
the intr_disable function pointer in struct cphy_ops in cxgb(4).
Instead define intr_disable and intr_restore as inline functions.
With intr_disable() an inline function, the I32_bit and F32_bit
macros now need to be visible in MI code and given the rather
poor names, this is not at all good. Define ARM_CPSR_F32 and
ARM_CPSR_I32 and use that instead of F32_bit and I32_bit (resp)
for now.
When using libc++ headers on FreeBSD, in combination with -std=c++98,
-ansi or -std=c++03, the long long type is not supported. So in this
case, several functions and types, like lldiv_t, strtoll(), are not
declared.
This should make it possible to use the libc++ headers in c++98 mode.
Note: libc++ is originally designed as a c++0x or higher library, so you
should still take care when using it with c++98 or c++03.
Noted by: Yamaya Takashi <yamayan@kbh.biglobe.ne.jp>
MFC after: 1 week
The device reports support for SATA Asynchronous Notification in its
IDENTIFY data, but returns error on attempt to enable that feature.
Make SATA XPT of CAM only report these errors, but not fail the device.
MFC after: 1 week
fail or not. The mbuf pointer is no longer valid, so
can't be reused after.
Fix igb_mq_start() where mbuf pointer was used after
drbr_enqueue().
This eventually leads us to all invocations of
igb_mq_start_locked() called with third argument as NULL.
This allows us to simplify this function.
Submitted by: Karim Fodil-Lemelin <fodillemlinkarim gmail.com>
Reviewed by: jfv
