explicitly test and panic. This should not ever happen, but if it does,
this is a preferred failure mode to a NULL pointer dereference in kernel.
Coverity CID: 1716
Found with: Coverity Prevent(tm)
We can now use LOCK_CLASS() as a stronger check in lockmgr_chain() as a
result. This required putting back lk_flags as lockmgr's use of flags
conflicted with other flags in lo_flags otherwise.
- Tweak 'show lock' output for lockmgr to match sx, rw, and mtx.
always 0. Previously we aligned threads on a minimum of 8-byte boundaries.
Note: This changes the uma zone to no longer cache align threads. We
really want the uma zone to do align threads to MAX(16, cache line size)
but there currently isn't a good way to express that to uma.
Submitted by: attilio
cpufreq_pre_change is called before the change, giving each driver a chance
to revoke the change. cpufreq_post_change provides the results of the
change (success or failure). cpufreq_levels_changed gives the unit number
of the cpufreq device whose number of available levels has changed. Hook
in all the drivers I could find that needed it.
* TSC: update TSC frequency value. When the available levels change, take the
highest possible level and notify the timecounter set_cputicker() of that
freq. This gets rid of the "calcru: runtime went backwards" messages.
* identcpu: updates the sysctl hw.clockrate value
* Profiling: if profiling is active when the clock changes, let the user
know the results may be inaccurate.
Reviewed by: bde, phk
MFC after: 1 month
other C files:
- Move sbcreatecontrol() and sbtoxsockbuf() to uipc_sockbuf.c. While
sbcreatecontrol() is really an mbuf allocation routine, it does its work
with awareness of the layout of socket buffer memory.
- Move pru_*() protocol switch stubs to uipc_socket.c where the non-stub
versions of several of these functions live. Likewise, move socket state
transition calls (soisconnecting(), etc) to uipc_socket.c. Moveo
sodupsockaddr() and sotoxsocket().
calling pru_detach we can be absolutely sure, that we don't have any
references to the socket in the stack.
This closes race between lockless sbdestroy() and data arriving on socket.
Reviewed by: rwatson
argument from a mutex to a lock_object. Add cv_*wait*() wrapper macros
that accept either a mutex, rwlock, or sx lock as the second argument and
convert it to a lock_object and then call _cv_*wait*(). Basically, the
visible difference is that you can now use rwlocks and sx locks with
condition variables using the same API as with mutexes.
until after the call to fdclose(). This closes an obscure race that
could result in the later call to fdclose() actually closing a different
file descriptor if another thread close()'s the file descriptor being
opened before fdrop() is called, so the fdrop() in kern_open() frees the
file object, then the second thread (or a third) creates a new file
descriptor which reuses both the same index and the same file pointer
thus tricking fdclose() in the first thread into thinking that the
original file was still open.
MFC after: 1 week
prison_priv_check() to decide what to do.
This change is suppose not to change current (security) behaviour
in any way.
This change is simlar to the change of PRIV_VFS_MOUNT in previous revision.
unsigned char. Weirdly, casting the 1 constant to u_char still produces
a signed integer result that is then used in the % computation. This
avoids that mess all together and causes a 0 pri to turn into 255 % 64
as we expect.
Reported by: kkenn (about 4 times, thanks)
late stages of unmount). On failure, the vnode is recycled.
Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.
Change getnewvnode() to no longer call insmntque(). Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.
Change vfs_hash_insert() to no longer lock the vnode. The caller now
has that responsibility.
Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup. Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.
Approved by: re (kensmith)
Reviewed by: kib
In collaboration with: kib
sosend_copyin().
- Use M_WAITOK instead of M_TRYWAIT in sosend_copyin().
- Don't check for NULL from M_WAITOK and return ENOBUFS.
M_WAITOK/M_TRYWAIT allocations don't fail with NULL.
Reviewed by: andre
Requested by: andre (2)
event. Locking primitives that support this (mtx, rw, and sx) now each
include their own foo_sleep() routine.
- Rename msleep() to _sleep() and change it's 'struct mtx' object to a
'struct lock_object' pointer. _sleep() uses the recently added
lc_unlock() and lc_lock() function pointers for the lock class of the
specified lock to release the lock while the thread is suspended.
- Add wrappers around _sleep() for mutexes (mtx_sleep()), rw locks
(rw_sleep()), and sx locks (sx_sleep()). msleep() still exists and
is now identical to mtx_sleep(), but it is deprecated.
- Rename SLEEPQ_MSLEEP to SLEEPQ_SLEEP.
- Rewrite much of sleep.9 to not be msleep(9) centric.
- Flesh out the 'RETURN VALUES' section in sleep.9 and add an 'ERRORS'
section.
- Add __nonnull(1) to _sleep() and msleep_spin() so that the compiler will
warn if you try to pass a NULL wait channel. The functions already have
a KASSERT to that effect.
These functions are intended to be used to drop a lock and then reacquire
it when doing an sleep such as msleep(9). Both functions accept a
'struct lock_object *' as their first parameter. The 'lc_unlock' function
returns an integer that is then passed as the second paramter to the
subsequent 'lc_lock' function. This can be used to communicate state.
For example, sx locks and rwlocks use this to indicate if the lock was
share/read locked vs exclusive/write locked.
Currently, spin mutexes and lockmgr locks do not provide working lc_lock
and lc_unlock functions.
GETATTRs being generated - one from lookup()/namei() and the other
from nfs_open() (for cto consistency). This change eliminates the
GETATTR in nfs_open() if an otw GETATTR was done from the namei()
path. Instead of extending the vop interface, we timestamp each attr
load, and use this to detect whether a GETATTR was done from namei()
for this syscall. Introduces a thread-local variable that counts the
syscalls made by the thread and uses <pid, tid, thread syscalls> as
the attrload timestamp. Thanks to jhb@ and peter@ for a discussion on
thread state that could be used as the timestamp with minimal overhead.
a thread is an idle thread, just see if it has the IDLETD
flag set. That flag will probably move to the pflags word
as it's permenent and never chenges for the life of the
system so it doesn't need locking.
- Properly note when a read lock is released.
- Always note when we contest on a read lock.
- Only note success of obtaining read locks for the first reader to match
the behavior of sx(9).
Reviewed by: kmacy
- Remove also "MP SAFE" after prior "MPSAFE" pass. (suggested by bde)
- Remove extra blank lines in some cases.
- Add extra blank lines in some cases.
- Remove no-op comments consisting solely of the function name, the word
"syscall", or the system call name.
- Add punctuation.
- Re-wrap some comments.
system calls now enter without Giant held, and then in some cases, acquire
Giant explicitly.
Remove a number of other MPSAFE annotations in the credential code and
tweak one or two other adjacent comments.
this patch the code behaves according to the comment on the line above.
Without this patch, a socket could cause SIGPIPE to be delivered to its
process, once with SO_NOSIGPIPE set, and twice without.
With this patch, the kernel now passes the sigpipe regression test.
Tested by: Anton Yuzhaninov
MFC after: 1 week
and optimize away unused stack values. The 48 bytes that the lock_profile_object
adds to the stack evidently has a measurable performance impact on certain workloads.
uipc_send in cases where only a global read lock is held by breaking
them out and avoiding the unpcb lock acquire in the common case. This
avoids deadlocks which manifested with X11, and should also marginally
further improve performance.
Reported by: sepotvin, brooks
- 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.
concurrency:
- Add per-unpcb mutexes protecting unpcb connection state, fields, etc.
- Replace global UNP mutex with a global UNP rwlock, which will protect the
UNIX domain socket connection topology, v_socket, and be acquired
exclusively before acquiring more than per-unpcb at a time in order to
avoid lock order issues.
In performance measurements involving MySQL, this change has little or no
overhead on UP (+/- 1%), but leads to a significant (5%-30%) improvement in
multi-processor measurements using the sysbench and supersmack benchmarks.
Much testing by: kris
Approved by: re (kensmith)
determine if it holds an exclusive rwlock reference or not. This is
non-ideal, but recursion scenarios in the network stack currently
require it.
Approved by: jhb
call which can easily lock up a system otherwise; instead,
return ENOBUFS as documented in a manpage, thus reverting
us to the FreeBSD 4.x behavior.
Reviewed by: rwatson
MFC after: 2 weeks
- only collect timestamps when a lock is contested - this reduces the overhead
of collecting profiles from 20x to 5x
- remove unused function from subr_lock.c
- generalize cnt_hold and cnt_lock statistics to be kept for all locks
- NOTE: rwlock profiling generates invalid statistics (and most likely always has)
someone familiar with that should review
PRIO_USER case, possibly also other places that deferences
p_ucred.
In the past, we insert a new process into the allproc list right
after PID allocation, and release the allproc_lock sx. Because
most content in new proc's structure is not yet initialized,
this could lead to undefined result if we do not handle PRS_NEW
with care.
The problem with PRS_NEW state is that it does not provide fine
grained information about how much initialization is done for a
new process. By defination, after PRIO_USER setpriority(), all
processes that belongs to given user should have their nice value
set to the specified value. Therefore, if p_{start,end}copy
section was done for a PRS_NEW process, we can not safely ignore
it because p_nice is in this area. On the other hand, we should
be careful on PRS_NEW processes because we do not allow non-root
users to lower their nice values, and without a successful copy
of the copy section, we can get stale values that is inherted
from the uninitialized area of the process structure.
This commit tries to close the race condition by grabbing proc
mutex *before* we release allproc_lock xlock, and do copy as
well as zero immediately after the allproc_lock xunlock. This
guarantees that the new process would have its p_copy and p_zero
sections, as well as user credential informaion initialized. In
getpriority() case, instead of grabbing PROC_LOCK for a PRS_NEW
process, we just skip the process in question, because it does
not affect the final result of the call, as the p_nice value
would be copied from its parent, and we will see it during
allproc traverse.
Other potential solutions are still under evaluation.
Discussed with: davidxu, jhb, rwatson
PR: kern/108071
MFC after: 2 weeks
freshly-loaded kernel module. To avoid various unload races, hide linker
files whose sysinit's are being run from userland so that they can't be
kldunloaded until after all the sysinit's have finished.
Tested by: gallatin
want an equivalent of DELAY(9) that sleeps instead of spins. It accepts
a wmesg and a timeout and is not interrupted by signals. It uses a private
wait channel that should never be woken up by wakeup(9) or wakeup_one(9).
Glanced at by: phk
check that the subject has read/write access to the vnode using the
vnode MAC check.
MFC after: 3 weeks
Submitted by: Spencer Minear <spencer_minear at securecomputing dot com>
Obtained from: TrustedBSD Project
garbage collection complications from general discussion of UNIX domain
sockets.
Staticize unp_addsockcred().
Remove XXX comment regarding Giant and v_socket -- v_socket is protected
by the global UNIX domain socket lock.
System V shared memory, now believed fixed in sysv_shm.c:1.109:
date: 2006/11/06 13:42:01; author: rwatson; state: Exp; lines: +65 -37
Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
This restores fine-grained privilege support to System V IPC.
PR: 106078
ignored on other systems I investigated when accessing an existing
memory segment rather than creating a new one. This call to ipcperm()
is the only one to pass in a complete mode flag to the permission
checks rather than a simple access request mask, and caused problems
for the revised ipcperm() based on the priv(9) interface, which can
now be restored.
PR: 106078
VFS privilege namespace: exceedquota, getquota, and setquota. Leave
UFS-specific quota configuration privileges in the UFS name space.
This renumbers VFS and UFS privileges, so requires rebuilding modules
if you are using security policies aware of privilege identifiers.
This is likely no one at this point since none of the committed MAC
policies use the privilege checks.
set real-time priority on a thread. It looks like this suser(9)
call was introduced after my first pass through replacing superuser
checks with named privilege checks.
As consequence, getdirentries() no longer needs to drop/reacquire
directory vnode lock, that would allow it to be reclaimed in between.
Reported and tested by: Peter Holm
Approved by: rodrigc (unionfs)
MFC after: 1 week
This way we may support multiple structures in v_data vnode field within
one file system without using black magic.
Vnode-to-file-handle should be VOP in the first place, but was made VFS
operation to keep interface as compatible as possible with SUN's VFS.
BTW. Now Solaris also implements vnode-to-file-handle as VOP operation.
VFS_VPTOFH() was left for API backward compatibility, but is marked for
removal before 8.0-RELEASE.
Approved by: mckusick
Discussed with: many (on IRC)
Tested with: ufs, msdosfs, cd9660, nullfs and zfs
a version that i posted earlier on the -current mailing list,
and subsequent feedback received.
The core of the change is just in sys/firmware.h and kern/subr_firmware.c,
while other files are just adaptation of the clients to the ABI change
(const-ification of some parameters and hiding of internal info,
so this is fully compatible at the binary level).
In detail:
- reduce the amount of information exported to clients in struct firmware,
and constify the pointer;
- internally, document and simplify the implementation of the various
functions, and make sure error conditions are dealt with properly.
The diffs are large, but the code is really straightforward now (i hope).
Note also that there is a subtle issue with the implementation of
firmware_register(): currently, as in the previous version, we just
store a reference to the 'imagename' argument, but we should rather
copy it because there is no guarantee that this is a static string.
I realised this while testing this code, but i prefer to fix it in
a later commit -- there is no regression with respect to the past.
Note, too, that the version in RELENG_6 has various bugs including
missing locks around the module release calls, mishandling of modules
loaded by /boot/loader, and so on, so an MFC is absolutely necessary
there. I was just postponing it until this cleanup to avoid doing
things twice.
MFC after: 1 week
of the special handling for ".." and perform an ISDOTDOT VOP_LOOKUP()
for a filesystem root vnode. Handle this case inside lookup().
Submitted by: tegge
PR: 92785
MFC after: 1 week
sonewconn() in unp_connect(). This avoids a race that occurs due to
v_socket being an uncounted reference, as the lock was being released in
order to call sonewconn(), which otherwise recurses into the UNIX domain
socket code via pru_attach, as well as holding the lock over a sleeping
memory allocation in uipc_attach(). Switch to a non-sleeping memory
allocation during UNIX domain socket attach.
This fix non-ideal in that it requires enabling recursion, but is a much
smaller change than moving to using true references for v_socket. The
reported panic occurs in unp_connect() following the return of
sonewconn().
Update copyright year.
Panic reported by: jhb
doing a CLEARFILE option. Do a vrele instead. This prevents
a panic later due to v_writecount being negative when the vnode
is taken off the freelist.
Submitted by: jhb
to become negative. This will detect the underflow when it
happens, instead of having it discovered when the vnode is
taken off the freelist, long after the offending process is long
gone.
- Fix these types in ULE as well. This fixes bugs in priority index
calculations in certain edge cases. (int)-1 % 64 != (uint)-1 % 64.
Reported by: kkenn using pho's stress2.
avoid holding the UNIX domain socket subsystem lock over soooptcopyin()
and sooptcopyout(). This problem was introduced when LOCAL_CREDS, and
LOCAL_CONNWAIT support were added.
Reviewed by: mdodd
sleep lock missed the witness code, and the system will panic
immediately on boot if WITNESS is enabled.
Changed the witness definition to the new type.
firmware in that module (eventhough this is a programming error) - drop the
reference to the module again.
Submitted by: Benjamin Close
MFC after: 3 days
minimize IPIs and rescheduling when scheduling like tasks while keeping
latency low for important threads.
1) An idle thread is running.
2) The current thread is worse than realtime and the new thread is
better than realtime. Realtime to realtime doesn't preempt.
3) The new thread's priority is less than the threshold.
support sched_4bsd.
- Rename the KTR level for non schedgraph parsed events. They take event
space from things we'd like to graph.
- Reset our slice value after we sleep. The slice is simply there to
prevent starvation among equal priorities. A thread which had almost
exhausted it's slice and then slept doesn't need to be rescheduled a
tick after it wakes up.
- Set the maximum slice value to a more conservative 100ms now that it is
more accurately enforced.
zone. Cluster allocations fail when this happens. Also processes that may have
blocked on cluster allocations will never be woken up. Thanks to rwatson for
an overview of the issue and pointers to the mbuma paper and his tool to dump
out UMA zones.
Reviewed by: andre@
negative. Use unsigned integers for sleep and run time so this doesn't
disturb sched_interact_score(). This should fix the invalid interactive
priority panics reported by several users.
file are after snaplock, while other ffs device buffers are before
snaplock in global lock order. By itself, this could cause deadlock
when bdwrite() tries to flush dirty buffers on snapshotted ffs. If,
during the flush, COW activity for snapshot needs to allocate block
and ffs_alloccg() selects the cylinder group that is being written
by bdwrite(), then kernel would panic due to recursive buffer lock
acquision.
Avoid dealing with buffers in bdwrite() that are from other side of
snaplock divisor in the lock order then the buffer being written. Add
new BOP, bop_bdwrite(), to do dirty buffer flushing for same vnode in
the bdwrite(). Default implementation, bufbdflush(), refactors the code
from bdwrite(). For ffs device buffers, specialized implementation is
used.
Reviewed by: tegge, jeff, Russell Cattelan (cattelan xfs org, xfs changes)
Tested by: Peter Holm
X-MFC after: 3 weeks (if ever: it changes ABI)
- Define our own maybe_preempt() as sched_preempt(). We want to be able
to preempt idlethread in all cases.
- Define our idlethread to require preemption to exit.
- Get the cpu estimation tick from sched_tick() so we don't have to worry
about errors from a sampling interval that differs from the time
domain. This was the source of sched_priority prints/panics and
inaccurate pctcpu display in top.
setrunqueue() was mostly empty. The few asserts and thread state
setting were moved to the individual schedulers. sched_add() was
chosen to displace it for naming consistency reasons.
- Remove adjustrunqueue, it was 4 lines of code that was ifdef'd to be
different on all three schedulers where it was only called in one place
each.
- Remove the long ifdef'd out remrunqueue code.
- Remove the now redundant ts_state. Inspect the thread state directly.
- Don't set TSF_* flags from kern_switch.c, we were only doing this to
support a feature in one scheduler.
- Change sched_choose() to return a thread rather than a td_sched. Also,
rely on the schedulers to return the idlethread. This simplifies the
logic in choosethread(). Aside from the run queue links kern_switch.c
mostly does not care about the contents of td_sched.
Discussed with: julian
- Move the idle thread loop into the per scheduler area. ULE wants to
do something different from the other schedulers.
Suggested by: jhb
Tested on: x86/amd64 sched_{4BSD, ULE, CORE}.
the mount options list with vfs_deleteopt(). At this point, the export
information is saved in mp->mnt_export, so we can delete
the "export" mount option from mp->mnt_optnew and mp->mnt_opt.
This fixes read-write/read-only update mounts (mount -u -o rw, mount -u -o ro)
of NFS exported directories.
For some reason, I could only reproduce the problem with a configuration
supplied by Andre:
- "options QUOTA" enabled in kernel config
- "/ -maproot=root 10.0.1.105" in /etc/exports
Reported by: kris, Andre Guibert de Bruet <andy siliconlandmark com>,
Andrzej Tobola <ato iem pw edu pl>
Tested by: Andre Guibert de Bruet
control data but no payload data is passed.
Change m_uiotombuf() to return at least one empty mbuf if the requested
length was zero. Add comment to sosend_dgram and sosend_generic().
Diagnoses by: jhb
Regression test by: rwatson
Pointy hat to. andre
--------------------------
[Deadlock] is caused by a lock order reversal in vfs_lookup(), where
[some] process is trying to lock a directory vnode, that is the parent
directory of covered vnode) while holding an exclusive vnode lock on
covering vnode.
A simplified scenario:
root fs var fs
/ A / (/var) D
/var B /log (/var/log) E
vfs lock C vfs lock F
Within each file system, the lock order is clear: C->A->B and F->D->E
When traversing across mounts, the system can choose between two lock orders,
but everything must then follow that lock order:
L1: C->A->B
|
+->F->D->E
L2: F->D->E
|
+->C->A->B
The lookup() process for namei("/var") mixes those two lock orders:
VOP_LOOKUP() obtains B while A is held
vfs_busy() obtains a shared lock on F while A and B are held (follows L1,
violates L2)
vput() releases lock on B
VOP_UNLOCK() releases lock on A
VFS_ROOT() obtains lock on D while shared lock on F is held
vfs_unbusy() releases shared lock on F
vn_lock() obtains lock on A while D is held (violates L1, follows L2)
dounmount() follows L1 (B is locked while F is drained).
Without unmount activity, vfs_busy() will always succeed without blocking
and the deadlock isn't triggered (the system behaves as if L2 is followed).
With unmount, you can get 4 processes in a deadlock:
p1: holds D, want A (in lookup())
p2: holds shared lock on F, want D (in VFS_ROOT())
p3: holds B, want drain lock on F (in dounmount())
p4: holds A, want B (in VOP_LOOKUP())
You can have more than one instance of p2.
The reversal was introduced in revision 1.81 of src/sys/kern/vfs_lookup.c and
MFCed to revision 1.80.2.1, probably to avoid a cascade of vnode locks when nfs
servers are dead (VFS_ROOT() just hangs) spreading to the root fs root vnode.
- Tor Egge
To fix the LOR, ups@ noted that when crossing the mount point, ni_dvp
is actually not used by the callers of namei. Thus, placeholder deadfs
vnode vp_crossmp is introduced that is filled into ni_dvp.
Idea by: ups
Reviewed by: tegge, ups, jeff, rwatson (mac interaction)
Tested by: Peter Holm
MFC after: 2 weeks
a power saving mode otherwise.
- If the thread is already bound in sched_bind() unbind it before
re-binding it to a new cpu. I don't like these semantics but they are
expected by some code in the tree. Patch by jkoshy.
the ipi settings. If NEEDRESCHED is set and an ipi is later delivered
it will clear it rather than cause extra context switches. However, if
we miss setting it we can have terrible latency.
- In sched_bind() correctly implement bind. Also be slightly more
tolerant of code which calls bind multiple times. However, we don't
change binding if another call is made with a different cpu. This
does not presently work with hwpmc which I believe should be changed.
- Switch back to direct modification of remote CPU run queues. This added
a lot of complexity with questionable gain. It's easy enough to
reimplement if it's shown to help on huge machines.
- Re-implement the old tdq_transfer() call as tdq_pickidle(). Change
sched_add() so we have selectable cpu choosers and simplify the logic
a bit here.
- Implement tdq_pickpri() as the new default cpu chooser. This algorithm
is similar to Solaris in that it tries to always run the threads with
the best priorities. It is actually slightly more complex than
solaris's algorithm because we also tend to favor the local cpu over
other cpus which has a boost in latency but also potentially enables
cache sharing between the waking thread and the woken thread.
- Add a bunch of tunables that can be used to measure effects of different
load balancing strategies. Most of these will go away once the
algorithm is more definite.
- Add a new mechanism to steal threads from busy cpus when we idle. This
is enabled with kern.sched.steal_busy and kern.sched.busy_thresh. The
threshold is the required length of a tdq's run queue before another
cpu will be able to steal runnable threads. This prevents most queue
imbalances that contribute the long latencies.
Approved by: gnn
Add a new function hashinit_flags() which allows NOT-waiting
for memory (or waiting). The old hashinit() function now
calls hashinit_flags(..., HASH_WAITOK);
call, its semantics were unintentionally changed. It went from
returning the time state to returning 0 or -1. Since 0 means time
normal, and non-zero effectively only shows up around leap seconds,
this went unnoticed until now. At least unnoticed until someone was
trying to run a binary they didn't have source for and it was
misbehaving...
Submitted by: Judah Levine
MFC After: 2 weeks
preemptions when adjusting the priority of a thread that is on a run
queue. This was only observed when FULL_PREEMPTION was enabled.
Reported by: kris
Diagnosed by: ups
MFC after: 1 week
the UCB license now excludes the advertising clause. I'm not
interested in it either, so move my copyright. This leaves
only a CGD copyright with the advertising clause.
MFC after: 3 days
- Sort by date in license blocks, oldest copyright first.
- All rights reserved after all copyrights, not just the first.
- Use (c) to be consistent with other entries.
MFC after: 3 days
of max() when computing the divisor in SCHED_TICK_PRI(). This prevents
cases where rounding down would allow the quotient to exceed
SCHED_PRI_RANGE.
- Garbage collect some unused flags and fields.
- Replace TDF_HOLD with sched_pin_td()/sched_unpin_td() since it simply
duplicated this functionality.
- Re-enable the rebalancer by default and fix the sysctl so it can be
modified.
marked idle, thus breaking cpu load balancing.
- Change sched_interact_update() to fix cases where the stored history
has expanded significantly rather than handling them in the callers. This
fixes a case where sched_priority() could compute a bad value.
- Add a sysctl to disable the global load balancer for experimentation.
sysctl and socket teardown by adding a reference count to the UNIX domain
pcb object and fixing the sysctl that enumerates unpcbs to grab a
reference on each unpcb while it builds the list to copy out to userland.
- Close a race between UNIX domain pcb garbage collection (unp_gc()) and
file descriptor teardown (fdrop()) by adding a new garbage collection
flag FWAIT. unp_gc() sets FWAIT while it walks the message buffers
in a UNIX domain socket looking for nested file descriptor references
and clears the flag when it is finished. fdrop() checks to see if the
flag is set on a file descriptor whose refcount just dropped to 0 and
waits for unp_gc() to clear the flag before completely destroying the
file descriptor.
MFC after: 1 week
Reviewed by: rwatson
Submitted by: ups
Hopefully makes the panics go away: mx1
setting ftick = ltick = ticks in schedinit().
- Update the priority when we are pulled off of the run queue and when we
are inserted onto the run queue so that it more accurately reflects our
present status. This is important for efficient priority propagation
functioning.
- Move the frequency test into sched_pctcpu_update() so we don't repeat it
each time we'd like to call it.
- Put some temporary work-around code in sched_priority() in case the tick
mechanism produces a bad priority. Eventually this should revert to an
assert again.
