- the issues with wakeup_one are due to address space clashes between
unrelated groups of threads.
- sleep() was removed in FreeBSD 2.2.
- date the page today, not 4 days ago.
- replace grammatically correct "woken" with "woken up" for
consistency with the function name.
to a READ_CAPACITY request rather than the maximum sector (off by one
problem). This causes a huge cascade of errors as the geom tasting
code tries to read the last sector (which isn't really there in the
face of this error). automated tools that manipulate disk labels and
such also have issues.
Create a new quirk READ_CAPACITY_OFFBY1 and add a quirk for the
SanDISK ImageMate that I have that suffers from this problem (the
SDDR-31). It intercepts the READ_CAPACITY response and adjusts it
from number of sectors to max sector for devices with this quirk.
Reading the Linux source suggests that there are a host of
other devices with this issue, including iPods and some popular
cameras. I've not added quirks for them, since I don't have the
devices in front of me to test.
it is initialized; use path instead.
This change fixes a panic when using atapicam in conjunction with CAMDEBUG,
which has been described under kern/103602.
Thanks to Josh Carroll <josh.carroll@gmail.com> for providing the traces
that allowed identifying this problem.
PR: kern/103602
MFC after: 1 week
- Fix missing initialization in kern_rwlock.c causing bogus times to be collected
- Move updates to the lock hash to after the lock is released for spin mutexes,
sleep mutexes, and sx locks
- Add new kernel build option LOCK_PROFILE_FAST - only update lock profiling
statistics when an acquisition is contended. This reduces the overhead of
LOCK_PROFILING to increasing system time by 20%-25% which on
"make -j8 kernel-toolchain" on a dual woodcrest is unmeasurable in terms
of wall-clock time. Contrast this to enabling lock profiling without
LOCK_PROFILE_FAST and I see a 5x-6x slowdown in wall-clock time.
sidewaysintpr(). This increases the accuracy of the per-interval
counts when they are interpreted as rates. Repeated calls to alarm(n)
give an average interval that is about 2 ticks larger than n and has
a large variance. Periodic itimers normally get the average almost
right but have similarly large variance (due to scheduling delays).
Statistics utilities should use clock_gettime() to determine the
actual interval, but it is still useful to maximize the accuracy of
the interval, especially for cases like netstat -w where counts are
displayed so the program cannot hide the inaccuracy in a rate
conversion.
arrangement that has no intrinsic internal knowledge of whether devices
it is given are truly multipath devices. As such, this is a simplistic
approach, but still a useful one.
The basic approach is to (at present- this will change soon) use camcontrol
to find likely identical devices and and label the trailing sector of the
first one. This label contains both a full UUID and a name. The name is
what is presented in /dev/multipath, but the UUID is used as a true
distinguishor at g_taste time, thus making sure we don't have chaos
on a shared SAN where everyone names their data multipath as "Fred".
The first of N identical devices (and N *may* be 1!) becomes the active
path until a BIO request is failed with EIO or ENXIO. When this occurs,
the active disk is ripped away and the next in a list is picked to
(retry and) continue with.
During g_taste events new disks that meet the match criteria for existing
multipath geoms get added to the tail end of the list.
Thus, this active/passive setup actually does work for devices which
go away and come back, as do (now) mpt(4) and isp(4) SAN based disks.
There is still a lot to do to improve this- like about 5 of the 12
recommendations I've received about it, but it's been functional enough
for a while that it deserves a broader test base.
Reviewed by: pjd
Sponsored by: IronPort Systems
MFC: 2 months
Linux does not check file descriptor when MAP_ANONYMOUS is set.
This should fix recent LTP test regressions.
Reported by: Scot Hetzel (swhetzel at gmail dot com)
netchild
case where it asynchronously exits burst mode on its own. Handle different
values of hz in sleep loop. Provide more debugging options to tune EC
behavior. These tunables/sysctls may be temporary and are not for user
access if the EC is working properly. Burst mode is now on by default for
testing and the poll interval has been increased from 100 to 500 us and
total timeout from 100 to 500 ms.
Hopefully this should be the first step of addressing reports of timeout
errors during battery or thermal access, especially on HP/Compaq laptops.
It is reasonably stable and should not cause a loss of functionality or
performance on systems that were previously working. Testing shows an
increase of responsiveness by ~75% on one system.
PR: kern/98171
