mount(2) system call:
* Add cmount hook to fdescfs and pseudofs (and, by extension, procfs and
linprocfs). This (mostly) restores the ability to mount these
filesystems using the old mount(2) system call (see below for the
rest of the fix).
* Remove not-NULL check for the data argument from the mount(2) entry
point. Per the mount(2) man page, it is up to the individual
filesystem being mounted to verify data. Or, in the case of procfs,
etc. the filesystem is free to ignore the data parameter if it does
not use it. Enforcing data to be not-NULL in the mount(2) system call
entry point prevented passing NULL to filesystems which ignored the
data pointer value. Apparently, passing NULL was common practice
in such cases, as even our own mount_std(8) used to do it in the
pre-nmount(2) world.
All userland programs in the tree were converted to nmount(2) long ago,
but I've found at least one external program which broke due to this
(presumably unintentional) mount(2) API change. One could argue that
external programs should also be converted to nmount(2), but then there
isn't much point in keeping the mount(2) interface for backward
compatibility if it isn't backward compatible.
When porting FreeBSD to a new platform, one of the more useful things to do is
get mi_startup() to let you know which SYSINIT it's up to. Most people tend to
whack a printf in the SYSINIT loop to print the address of the function it's
about to call. Going one better, jhb made a version that uses DDB to look up
the name of the function and print that instead. This version is essentially
his with the addition of some ifdeffery to make it optional and to allow it to
work (although using only the function address, not the symbol) if you forgot
to enable DDB.
All the cool bits by: jhb
Approved by: scottl, rink, cognet, imp
vn_start_write() is always called earlier in the code path and calling
the function recursively may lead to a deadlock.
Confirmed by: tegge
MFC after: 2 weeks
vn_finished_write() should also be called only then.
BTW. I fixed two functions here: vn_rdwr() and vn_write(). The latter seems
to be unused.
MFC after: 3 weeks
buffers to go on the buf daemon's DIRTYGIANT queue.
- Set BO_NEEDSGIANT on ffs's devvp since the ffs_copyonwrite handler
runs in the context of the buf daemon and may require Giant.
than trying to optimize it into a single lock. This adds more calls to
lock giant with non smpsafe filesystems but is the only way to reliably
hold the correct lock.
- Remove an invalid assert in the mountedhere case in lookup and fix the
code to properly deal with the scenario. We can actually have a lookup
that returns dp == dvp with mountedhere set with certain unmount races.
Tested by: kris
Reported by: kris/mohans
problems in ddb:
- "show threadchain [thread]" will start with the specified thread (or the
current kdb thread by default) and show it's state. If it is blocked on
a lock, it will find the owner of the lock and show its state, etc.
- "show allchains" will find all of the threads that are blocked on a
lock (but do not have any threads blocked on a lock they hold) and show
the resulting thread chain.
- "show lockchain <lock>" takes a pointer to a lock_object (such as a
mutex or rwlock). If there is a turnstile for that lock, then it will
display all the threads blocked on the lock. In addition, for each
thread blocked on the lock, it will display any contested locks they
hold, and recurse on those locks to show any threads blocked on those
locks, etc.
file lock, in the style of fgetsock().
Modify accept1() to use getsock() instead of fgetsock(), relying on the
file descriptor reference rather than an acquired socket reference to
prevent the listen socket from being destroyed during accept(). This
avoids additional reference count operations, which should improve
performance, and also avoids accept1() operating on a socket whose file
descriptor has been torn down, which may have resulted in protocol
shutdown starting.
MFC after: 3 months
function along with the remainder of the reference checking code. Move
comment from body to header with remainder of comments. Inclusion of a
socket in a completed connection queue counts as a true reference, and
should not be handled as an under-documented edge case.
MFC after: 3 months
locked. In general the adaptive spinning is similar to the same code
for mutexes with some extra trickiness in rw_wunlock_hard(). Specifically,
even though both wait bits might be set and we might have a turnstile with
at least one waiting thread, there might not be any threads blocked on the
queue we are not waking up (they might all be spinning), and we should
only preserve the waiting flag for the queue we aren't waking up if there
are in fact threads blocked on that queue. Secondly, there might not be
any threads blocked on the queue we have chosen to waken threads from
(there might only be threads blocked on the other queue and the threads
for this queue are all spinning) in which case we disown the turnstile
instead of doing a braodcast and unpend.
use it in places that only care about the write owner instead of
rw_owner() as a baby step towards limited read-lock owner.
- Tidy the code that sets the WAITER flag bits to not duplicate a test
around the atomic operation and the KTR trace in both of the lock
functions.
with a given module_t. I use this in some the MOD_LOAD event handler for
some test kernel modules to ask the kernel linker to look up the linker
sets in my test modules. (I use linker sets to generate the list of
possible events that I then signal to execute via a sysctl. On non-amd64,
ld(8) would resolve the entire linker set, but on amd64 I have to ask the
kernel linker to do it for me, and having the kernel linker do it works on
all archs.)
if the specified priority is zero. This avoids a race where the calling
thread could read a snapshot of it's current priority, then a different
thread could change the first thread's priority, then the original thread
would call sched_prio() inside msleep() undoing the change made by the
second thread. I used a priority of zero as no thread that calls msleep()
or tsleep() should be specifying a priority of zero anyway.
The various places that passed 'curthread->td_priority' or some variant
as the priority now pass 0.
compiler doesn't decide to cache td_state. Cachine the state would cause
the spinning thread to not notice when the owning thread stopped executing
(if it was preempted for example) which could result in livelock.
than keeping it locked until we exit the function to optimize the case
where the lock would be dropped and later reacquired. The optimization
was broken when kevent's were moved from UFS to VFS and the knote list
lock for a vnode kevent became the lockmgr vnode lock. If one tried
to use a kqueue that contained events for a kqueue fd followed by a vnode,
then the kq global lock would end up being held when the vnode lock was
acquired which could result in sleeping with a mutex held (and subsequent
panics) if the vnode lock was contested.
Reviewed by: jmg
Tested by: ps (on 6.x)
MFC after: 3 days
not need to clear it now, this should fix panic when msleep is recursivly
called. Patch is slightly adjusted after review.
Reviewed by: jhb
Tested by: Csaba Henk, csaba-ml at creo.hu
MFC after: 3 days
doesn't appear to be protecting anything. Most of consumers funsetownlst(9)
do not appear to be picking up Giant anywhere. This was originally a part
of my Giant exit(2) clean up revision 1.272 but I thought it was a good idea
to leave it out until we were able to analyze it better.
Tested by: kris
MFC after: 3 weeks
as being undocumented in Stevens, and was broken in 1997 during network
stack infrastructure work. It is the one remaining (and incorrect)
direct protocol reference to raw_usrreq.pru_attach; this is incorrect
because the raw socket code assumes that raw_uattach is called only after
the protocol has allocated a PCB.
MFC after: 3 months
recycling for an unrelated filesystem. I really don't like potentially
acquiring giant in the context of a giantless filesystem but there
are reasonable objections to removing the recycling from this path.
Sponsored by: Isilon Systems, Inc.
PCB in which the context of stopped CPUs is stored. To access this
PCB from KDB, we introduce a new define, called KDB_STOPPEDPCB. The
definition, when present, lives in <machine/kdb.h> and abstracts
where MD code saves the context. Define KDB_STOPPEDPCB on i386,
amd64, alpha and sparc64 in accordance to previous code.
intr_disable() and intr_restore() resp. Previously, critical
regions would have interrupts disabled, but that was changed.
Consequently, the debugger could run with interrupts enabled.
This could cause problems for the low-level console code where
received characters would trigger an interrupt that causes
the interrupt handler to read the character instead of the
cngetc() function.
rather than an error. Detaches do not "fail", they other occur or
the protocol flags SS_PROTOREF to take ownership of the socket.
soclose() no longer looks at so_pcb to see if it's NULL, relying
entirely on the protocol to decide whether it's time to free the
socket or not using SS_PROTOREF. so_pcb is now entirely owned and
managed by the protocol code. Likewise, no longer test so_pcb in
other socket functions, such as soreceive(), which have no business
digging into protocol internals.
Protocol detach routines no longer try to free the socket on detach,
this is performed in the socket code if the protocol permits it.
In rts_detach(), no longer test for rp != NULL in detach, and
likewise in other protocols that don't permit a NULL so_pcb, reduce
the incidence of testing for it during detach.
netinet and netinet6 are not fully updated to this change, which
will be in an upcoming commit. In their current state they may leak
memory or panic.
MFC after: 3 months
than an int, as an error here is not meaningful. Modify soabort() to
unconditionally free the socket on the return of pru_abort(), and
modify most protocols to no longer conditionally free the socket,
since the caller will do this.
This commit likely leaves parts of netinet and netinet6 in a situation
where they may panic or leak memory, as they have not are not fully
updated by this commit. This will be corrected shortly in followup
commits to these components.
MFC after: 3 months
the file descriptor reference, rather than paying additional lock
operations to acquire a socket reference from the file descriptor.
This will also help to ensure that file descriptor based socket
requests are not delivered to a socket after close. Most consumers
have already been converted to this model.
MFC after: 3 months
be present at this point. We will eventually remove this assert because
the socket layer should never look at so_pcb, but for now it's a useful
debugging tool.
MFC after: 3 months
socket calls relating to the creation and destruction of sockets. This
will eventually form the foundation of socket(9), but is currently in too
much flux to do so.
MFC after: 3 months
called.
- vfs_getvfs has to return a reference to prevent the returned mountpoint
from changing identities.
- Release references acquired via vfs_getvfs.
Discussed with: tegge
Tested by: kris
Sponsored by: Isilon Systems, Inc.
mount memory from being reclaimed. This resolves a number of race
conditions described in vfs_default.c and introduced with the
VFS_LOCK_GIANT macros.
- Let the mtx and lock remain valid after the mount structure has been
freed by using init and fini calls. Technically fini will never be
called but is included for completeness.
- Consistently use lockmgr directly rather than lockmgr to lock and
vfs_unbusy to unlock.
Discussed with: tegge
Tested by: kris
Sponsored by: Isilon Systems, Inc.
- Move the vn_lock of the dvp until after we've unbusied the filesystem
to avoid a LOR with the mount point lock.
- In the v_mountedhere while loop we acquire a new instance of giant each
time through without releasing the first. This would cause us to leak
Giant.
Sponsored by: Isilon Systems, Inc.
requires Giant. It is set in bgetvp and cleared in brelvp.
- Create QUEUE_DIRTY_GIANT for dirty buffers that require giant.
- In the buf daemon, only grab giant when processing QUEUE_DIRTY_GIANT and
only if we think there are buffers in that queue.
Sponsored by: Isilon Systems, Inc.
failing, print a message when we fail for some reason as most callers do
not check the return value (e.g. 'cuz they're called from SYSINIT)
Reviewed by: scottl
MFC after: 1 week
controllers typically have multiple channels and support a number
of serial communications protocols. The scc(4) driver is itself
an umbrella driver that delegates the control over each channel
and mode to a subordinate driver (like uart(4)).
The scc(4) driver supports the Siemens SAB 82532 and the Zilog
Z8530 and replaces puc(4) for these devices.
a lock's priority to a sleeping thread. When we panic, dump a stack
trace of the thread that is asleep if DDB is compiled into the kernel
just before calling panic(). This is much more informative and useful
for debugging than the current behavior of getting a page fault and not
having an easy way of determining which thread caused the original problem.
MFC after: 1 week
a race where data could come in before we clear the INFLUX flag, and get
skipped over by knote (and hence never be activated, though it should of
been)...
Found by: glebius & co.
Reviewed by: glebius
MFC after: 3 days
generating a coredump as the result of a signal.
- Fix a bug where we could leak a Giant lock if vn_start_write() failed
in coredump().
Reported by: jmg (2)
and use that instead of testing fdidx against -1 to determine if it should
release Giant if Giant was locked due to the requested file residing on a
non-MPSAFE VFS.
Discussed with: jeff
arguments. The first one is never used (all callers pass in 0); the
second is sometimes used to pass in a struct timespec * which is used as
a timeout and never modified. Constify that argument so callers can pass
a const struct timespec * without jumping through hoops.
acquiring Giant in kern_sendfile().
Guard against the forced reclamation of a vnode in kern_sendfile().
Discussed with: jeff
Reviewed by: tegge
MFC after: 3 weeks
REGRESSION is enabled, allows user space to dictate that sonewconn()
should skip it's "skip the hard work" check to see if the listen
queue is full, and instead proceed with allocation of a socket and
trimming of the overflowed queue. This makes it easier to test the
queue overflow logic.
MFC after: 1 month
Kernel changes:
Inform hwpmc of executable objects brought into the system by
kldload() and mmap(), and of their removal by kldunload() and
munmap(). A helper function linker_hwpmc_list_objects() has been
added to "sys/kern/kern_linker.c" and is used by hwpmc to retrieve
the list of currently loaded kernel modules.
The unused `MAPPINGCHANGE' event has been deprecated in favour
of separate `MAP_IN' and `MAP_OUT' events; this change reduces
space wastage in the log.
Bump the hwpmc's ABI version to "2.0.00". Teach hwpmc(4) to
handle the map change callbacks.
Change the default per-cpu sample buffer size to hold
32 samples (up from 16).
Increment __FreeBSD_version.
libpmc(3) changes:
Update libpmc(3) to deal with the new events in the log file; bring
the pmclog(3) manual page in sync with the code.
pmcstat(8) changes:
Introduce new options to pmcstat(8): "-r" (root fs path), "-M"
(mapfile name), "-q"/"-v" (verbosity control). Option "-k" now
takes a kernel directory as its argument but will also work with
the older invocation syntax.
Rework string handling in pmcstat(8) to use an opaque type for
interned strings. Clean up ELF parsing code and add support for
tracking dynamic object mappings reported by a v2.0.00 hwpmc(4).
Report statistics at the end of a log conversion run depending
on the requested verbosity level.
Reviewed by: jhb, dds (kernel parts of an earlier patch)
Tested by: gallatin (earlier patch)
VFS_LOCK_GIANT/VFS_UNLOCK_GIANT calls. This completely removes Giant
acquisition in the syscall path for ffs.
Bug fix to kern_fhstatfs from: Todd Miller <Todd.Miller@sparta.com>
Sponsored by: Isilon Systems, Inc.
"fdinit() fails to initialize newfdp->fd_fd.fd_lastfile to -1. This breaks
fdcopy() which will incorrectly set newfdp->fd_freefile to 1 if no files are
open and the last file descriptor marked as unused for fdp was 0. This later
causes descriptor 0 to be unavailable in newfdp when the optimization is
enabled.
When the last file descriptor previously marked as used is nonzero and marked
as unused, fdunused() incorrectly sets fdp->fd_lastfile to fd - 1 due to
fd_last_used() returning (size - 1). This hides the problem that breaks the
optimization."
This allows us to keep the optimization, while un-breaking it.
This is a RELENG_6 candidate.
PR: kern/87208
MFC after: 1 week
Submitted by: tegge
the target directory or file. This case should fail in the filesystem
anyway and perhaps kern_rename() should catch it.
Sponsored by: Isilon Systems, Inc.
really breaking things. Simple "close(0); dup(fd)" does not return descriptor
"0" in some cases. Further, this change also breaks some MAC interactions with
mac_execve_will_transition(). Under certain circumstances, fdcheckstd() can
be called in execve(2) causing an assertion that checks to make sure that
stdin, stdout and stderr reside at indexes 0, 1 and 2 in the process fd table
to fail, resulting in a kernel panic when INVARIANTS is on.
This should also kill the "dup(2) regression on 6.x" show stopper item on the
6.1-RELEASE TODO list.
This is a RELENG_6 candidate.
PR: kern/87208
Silence from: des
MFC after: 1 week
defined for an in-use socket. This allows us to eliminate countless tests
of whether so_pcb is non-NULL, eliminating dozens of error cases. For
now, retain the call to sotryfree() in the uipc_abort() path, but this
will eventually move to soabort().
These new assumptions should be largely correct, and will become more so
as the socket/pcb reference model is fixed. Removing the notion that
so_pcb can be non-NULL is a critical step towards further fine-graining
of the UNIX domain socket locking, as the so_pcb reference no longer
needs to be protected using locks, instead it is a property of the socket
life cycle.
consumers ignore the return value, soabort() is required to succeed,
and protocols produce errors here to report multiple freeing of the
pcb, which we hope to eliminate.
specified, the rightmost option takes effect." Fix code to obey
this. This makes e.g. "mount -r /usr" or "mount -ar" actually
mount file systems read-only.
Fix detection of active unlinked files by checking VI_OWEINACT and
VI_DOINGINACT in addition to v_usecount.
Defer inactive handling for unlinked files if the file system is mostly
suspended (secondary writes being blocked).
Perform deferred inactive handling after the file system is resumed.
triggers.
This should eliminate all the trivial messages which result from minor
increases in cpu_tick frequency.
Machines which don't du cpu clock fiddling shouldn't issue "backwards"
messages now.
Laptops and other machines where the initial estimate of cputicks may be
waaaay off will still issue warnings.
replacement for vn_write_suspend_wait() to better account for secondary write
processing.
Close race where secondary writes could be started after ffs_sync() returned
but before the file system was marked as suspended.
Detect if secondary writes or softdep processing occurred during vnode sync
loop in ffs_sync() and retry the loop if needed.
whether or not to allocate a full mbuf cluster rather than just a plain
mbuf when adding on additional mbufs in m_getm(). In practice, there wasn't
any resulting mem trashing since m_getm() doesn't ever allocate an mbuf with
a packet header, and MINCLSIZE is the available payload in an mbuf with a
header rather than the available payload in a plain mbuf.
Discussed with: andre (lightly)
Releasing items from the mt_zone can not be done by a simple
uma_zfree() call since mt_zone is allocated with the UMA_ZONE_MALLOC
flag. Use uma_zfree_arg instead and supply the slab.
This bug caused panics in low memory situations on unloading kernel
modules containing MALLOC_DEFINE(..) statements.
Submitted by: ups
be called without any vnode locks held. Remove calls to vn_start_write() and
vn_finished_write() in vnode_pager_putpages() and add these calls before the
vnode lock is obtained to most of the callers that don't already have them.
has many positive effects including improved smp locking, reducing
interdependencies between mounts that can lead to deadlocks, etc.
- Add the softdep worklist and various counters to the ufsmnt structure.
- Add a mount pointer to the workitem and remove mount pointers from the
various structures derived from the workitem as they are now redundant.
- Remove the poor-man's semaphore protecting softdep_process_worklist and
softdep_flushworklist. Several threads may now process the list
simultaneously.
- Add softdep_waitidle() to block the thread until all pending
dependencies being operated on by other threads have been flushed.
- Use softdep_waitidle() in unmount and snapshots to block either
operation until the fs is stable.
- Remove softdep worklist processing from the syncer and move it into the
softdep_flush() thread. This thread processes all softdep mounts
once each second and when it is called via the new softdep_speedup()
when there is a resource shortage. This removes the softdep hook
from the kernel and various hacks in header files to support it.
Reviewed by/Discussed with: tegge, truckman, mckusick
Tested by: kris
so other threads can not see it if we unlock the proc
lock (this can happen in knlist_delete). Don't do wakeup,
it is not necessary.
2. Decrease kaio_buffer_count in biohelper rather than
doing it in aio_bio_done_notify.
3. In aio_bio_done_notify, don't send notification if KAIO_RUNDOWN
was set, because the process is already in single thread mode.
4. Use assignment to initialize aiothreadflags.
5. AIOCBLIST_RUNDOWN is not useful, axe the code using it.
6. use LIO_NOP instead of zero.
callout_drain() logic. We no longer need a separate non-spin mutex to
do sleep/wakeup with, instead we can now just use the one spin mutex to
manage all the callout functionality.
the last reference is dropped. I forgot that vnodes can stick around
for a very long time until processes discover that they are dead. This
means that a vnode reference is not sufficient to keep the mount
referenced and even more code will be required to ref mount points.
Discovered by: kris
- Reorder the events in exit(2) slightly so that we trigger the S_EXIT
stop event earlier. After we have signalled that, we set P_WEXIT and
then wait for any processes with a hold on the vmspace via PHOLD to
release it. PHOLD now KASSERT()'s that P_WEXIT is clear when it is
invoked, and PRELE now does a wakeup if P_WEXIT is set and p_lock drops
to zero.
- Change proc_rwmem() to require that the processing read from has its
vmspace held via PHOLD by the caller and get rid of all the junk to
screw around with the vmspace reference count as we no longer need it.
- In ptrace() and pseudofs(), treat a process with P_WEXIT set as if it
doesn't exist.
- Only do one PHOLD in kern_ptrace() now, and do it earlier so it covers
FIX_SSTEP() (since on alpha at least this can end up calling proc_rwmem()
to clear an earlier single-step simualted via a breakpoint). We only
do one to avoid races. Also, by making the EINVAL error for unknown
requests be part of the default: case in the switch, the various
switch cases can now just break out to return which removes a _lot_ of
duplicated PRELE and proc unlocks, etc. Also, it fixes at least one bug
where a LWP ptrace command could return EINVAL with the proc lock still
held.
- Changed the locking for ptrace_single_step(), ptrace_set_pc(), and
ptrace_clear_single_step() to always be called with the proc lock
held (it was a mixed bag previously). Alpha and arm have to drop
the lock while the mess around with breakpoints, but other archs
avoid extra lock release/acquires in ptrace(). I did have to fix a
couple of other consumers in kern_kse and a few other places to
hold the proc lock and PHOLD.
Tested by: ps (1 mostly, but some bits of 2-4 as well)
MFC after: 1 week
modules prior to looking up the directory which we will cover to avoid
this problem in mount.
- We must hold the coveredvp locked before we can busy the mountpoint to
prevent a lock order reversal with the vfs_busy() in lookup which holds
the directory lock prior to doing a vfs_busy(). The directory lock is
required to safely clear the v_mountedhere field on the directory.
MFC After: 1 week
prevent the mount point from going away while we're waiting on the lock.
The ref does not need to persist once we have the lock because the
lock prevents the mount point from being unmounted.
MFC After: 1 week
the VFS_STATFS call to prevent the mount from disappearing while we're
stating.
- Convert these routines to use MPSAFE namei semantics.
MFC After: 1 week
a calcru() wrapper that passes a local rusage_ext on the stack that is
a snapshot to do the calculations on. Now we can pass p->p_crux to
calcru1() in calccru() again which fixes the issues with runtime going
backwards messages when dead processes are harvested by init.
Reviewed by: phk
Tested by: Stefan Ehmann shoesoft at gmx dot net
can't be changed from userland. Make them read-only and provide
descriptions.
kern.ipc.max_datalen must never be less than one byte. Enforce this
with a panic in net_init_domain().
Sponsored by: TCP/IP Optimization Fundraise 2005
MFC after: 3 days
jumbo mbuf clusters. To make the variable size clear they are named
MJUMPAGESIZE.
Having jumbo clusters with the native PAGE_SIZE is more useful than
a fixed 4k size according the device driver writers using this API.
The 9k and 16k jumbo mbuf clusters remain unchanged.
Requested by: glebius, gallatin
Sponsored by: TCP/IP Optimization Fundraise 2005
MFC after: 3 days
suspension code. When a thread A is going to sleep, it calls
sleepq_catch_signals() to detect any pending signals or thread
suspension request, if nothing happens, it returns without
holding process lock or scheduler lock, this opens a race
window which allows thread B to come in and do process
suspension work, however since A is still at running state,
thread B can do nothing to A, thread A continues, and puts
itself into actually sleeping state, but B has never seen it,
and it sits there forever until B is woken up by other threads
sometimes later(this can be very long delay or never
happen). Fix this bug by forcing sleepq_catch_signals to
return with scheduler lock held.
Fix sleepq_abort() by passing it an interrupted code, previously,
it worked as wakeup_one(), and the interruption can not be
identified correctly by sleep queue code when the sleeping
thread is resumed.
Let thread_suspend_check() returns EINTR or ERESTART, so sleep
queue no longer has to use SIGSTOP as a hack to build a return
value.
Reviewed by: jhb
MFC after: 1 week
remote CPU. While here, abstract thread suspension code into a function
called sig_suspend_threads, the function is called when a process received
a STOP signal.
Keep accounting time (in per-cpu) cputicks and the statistics counts
in the thread and summarize into struct proc when at context switch.
Don't reach across CPUs in calcru().
Add code to calibrate the top speed of cpu_tickrate() for variable
cpu_tick hardware (like TSC on power managed machines).
Don't enforce monotonicity (at least for now) in calcru. While the
calibrated cpu_tickrate ramps up it may not be true.
Use 27MHz counter on i386/Geode.
Use TSC on amd64 & i386 if present.
Use tick counter on sparc64
Rename struct thread's td_sticks to td_pticks, we will need the
other name for more appropriately named use shortly. Reduce it
from uint64_t to u_int.
Clear td_pticks whenever we enter the kernel instead of recording
its value as reference for userret(). Use the absolute value of
td->pticks in userret() and eliminate third argument.
Keep track of time spent by the cpu in various contexts in units of
"cputicks" and scale to real-world microsec^H^H^H^H^H^H^H^Hclock_t
only when somebody wants to inspect the numbers.
For now "cputicks" are still derived from the current timecounter
and therefore things should by definition remain sensible also on
SMP machines. (The main reason for this first milestone commit is
to verify that hypothesis.)
On slower machines, the avoided multiplications to normalize timestams
at every context switch, comes out as a 5-7% better score on the
unixbench/context1 microbenchmark. On more modern hardware no change
in performance is seen.
for acctwatch() runs to be negative or zero as this could result in either
a possible hang (or panic if INVARIANTS is on). Previously the accounting
code handled the <= 0 case by calling acctwatch on every clock tick (eww!)
due to an implementation detail of callout_reset(). (Tick counts of
<= 0 are converted to 1).
MFC after: 3 days
instead of calling acctwatch() from softclock. The acctwatch() function
needs to hold an sx lock and also makes a VFS call, and neither of these
are good things (or safe) to do from a callout. The kthread only exists
and is running when accounting is turned on; it is started and stopped
as needed. I didn't run acctwatch() via the thread taskqueue at Robert's
request as he was worried that if the accounting file was over NFS the
VFS_STAT() calls might stall other work on the taskqueue.
- Add an acct_disable() function to take care of closing the accounting
vnode and cleaning up so we don't duplicate the same code in two
different places.
MFC after: 3 days
the callers if the exec either succeeds or fails early.
- Move the code to call exit1() if the exec fails after the vmspace is
gone to the bottom of kern_execve() to cut down on some code duplication.
vfs_mount_destroy waiting for this ref to hit 0. We don't print an
error if we are rebooting as the root mount always retains some refernces
by init proc.
- Acquire a mnt ref for every vnode allocated to a mount point. Drop this
ref only once vdestroy() has been called and the mount has been freed.
- No longer NULL the v_mount pointer in delmntque() so that we may release
the ref after vgone() has been called. This allows us to guarantee
that the mount point structure will be valid until the last vnode has
lost its last ref.
- Fix a few places that rely on checking v_mount to detect recycling.
Sponsored by: Isilon Systems, Inc.
MFC After: 1 week
over from the Darwin implementation.
When we implement a system call as a wrapper to sysctl(), audit it as
AUE_SYSCTL. This leads to greater compatibility with Solaris audit
trails as sysctl() argument tokens are not the same as the ones for
the originaly system calls (i.e., setdomainname()).
Replace references to AUE_ events that are equivilent to AUE_NULL with
AUE_NULL. In the case of process signal configuration, this is
because these events do not require auditing.
Move from the Darwin spelling of getsockopt() to the FreeBSD/Solaris
one.
Audit nmount().
Obtained from: TrustedBSD Project
audit thread exit, but should that happen, this will prevent
unhappiness, as the thread exit system call will never return, and
hence not commit the record.
Pointed out by/with: cognet
Obtained from: TrustedBSD Project
This should not happen, but with this assert, brueffer and I would
not have spent 45 minutes trying to figure out why he wasn't
seeing audit records with the audit version in CVS.
Obtained from: TrustedBSD Project
and vnode attribute information for looked up vnodes during the lookup
operation. This will allow consumers of namei() to specify that this
information be added to the in-process audit record.
Submitted by: wsalamon
Obtained from: TrustedBSD Project
vnode is from a file system that is not MPSAFE, as vrele() expects
Giant to be held when it is called on a non-MPSAFE vnode.
Spotted by: kris
Tested by: glebius
the system when brelse() was called with B_RELBUF set on the buffer. This
could be a problem when the system was low on memory, had many buffers on
QUEUE_EMPTYKVA and started to traverse directories. For each getnewbuf(),
pages were allocated from the system, driving the free reserve downwards.
For each brelse(), the system put the buffer on QUEUE_CLEAN, with B_INVAL
set.
This commit changes the semantics of B_RELBUF to also free pages from
non-VMIO buffers.
Reviewed by: alc
- td_ar to struct thread, which holds the in-progress audit record during
a system call.
- p_au to struct proc, which holds per-process audit state, such as the
audit identifier, audit terminal, and process audit masks.
In the earlier implementation, td_ar was added to the zero'd section of
struct thread. In order to facilitate merging to RELENG_6, it has been
moved to the end of the data structure, requiring explicit
initalization in the thread constructor.
Much help from: wsalamon
Obtained from: TrustedBSD Project
without Giant held. Do this by tracking the vfslocked state for
the directory seperate from the child. This is only important
in the case where we cross a mountpoint.
Sponsored by: Isilon Systems, Inc.
MFC After: 3 days
on a lock held the last usecount ref on a vnode and the lock failed we
would not call INACTIVE. Solve this by only holding a holdcnt to prevent
the vnode from disappearing while we wait on vn_lock. Other callers
may now VOP_INACTIVE while we are waiting on the lock, however this race
is acceptable, while losing INACTIVE is not.
Discussed with: kan, pjd
Tested by: kkenn
Sponsored by: Isilon Systems, Inc.
MFC After: 1 week
directory. vrele() may lock the passed vnode, which in these cases would
give an invalid lock order of child -> parent. These situations are
deadlock prone although do not typically deadlock because the vrele
is typically not releasing the last reference to the vnode. Users of
vrele must consider it as a call to vn_lock() and order it appropriately.
MFC After: 1 week
Sponsored by: Isilon Systems, Inc.
Tested by: kkenn
This logic change was introduced in revision 1.74:
Correct an oversight in jail() that allowed processes in jail to access
ptys in ways that might be unethical, especially towards processes not in
jail, or in other jails.
It should be fine to allow root in the host environment to do this. This
allows for more effective monitoring of prisons from the host environment.
Discussed with: rwatson
MFC after: 1 week
It detects both: buffer underflows and buffer overflows bugs at runtime
(on free(9) and realloc(9)) and prints backtraces from where memory was
allocated and from where it was freed.
Tested by: kris
work by yar, thompsa and myself. The checksum offloading part also involves
work done by Mihail Balikov.
The most important changes:
o Instead of global linked list of all vlan softc use a per-trunk
hash. The size of hash is dynamically adjusted, depending on
number of entries. This changes struct ifnet, replacing counter
of vlans with a pointer to trunk structure. This change is an
improvement for setups with big number of VLANs, several interfaces
and several CPUs. It is a small regression for a setup with a single
VLAN interface.
An alternative to dynamic hash is a per-trunk static array with
4096 entries, which is a compile time option - VLAN_ARRAY. In my
experiments the array is not an improvement, probably because such
a big trunk structure doesn't fit into CPU cache.
o Introduce an UMA zone for VLAN tags. Since drivers depend on it,
the zone is declared in kern_mbuf.c, not in optional vlan(4) driver.
This change is a big improvement for any setup utilizing vlan(4).
o Use rwlock(9) instead of mutex(9) for locking. We are the first
ones to do this! :)
o Some drivers can do hardware VLAN tagging + hardware checksum
offloading. Add an infrastructure for this. Whenever vlan(4) is
attached to a parent or parent configuration is changed, the flags
on vlan(4) interface are updated.
In collaboration with: yar, thompsa
In collaboration with: Mihail Balikov <mihail.balikov interbgc.com>
this is more consistent with the placement of slaves in /dev/pts. The
actual name doesn't matter as it's not part of the exposed API or used by
libc. In some sense, it would be nice if these device nodes didn't have to
have names in devfs at all.
Suggested by: Stephen McKay <smckay at internode dot on dot net>
specially crafted module. There are several handrolled sollutions to this
problem in the tree already which will be replaced with this. They include
iwi(4), ipw(4), ispfw(4) and digi(4).
No objection from: arch
MFC after: 2 weeks
X-MFC after: some drivers have been converted
implementation is by no means perfect as far as some of the algorithms
that it uses and the fact that it is missing some functionality (try
locks and upgrades/downgrades are not there yet), however it does seem
to work in my local testing. There is more detail in the comments in the
code, but the short version follows.
A reader/writer lock is very much like a regular mutex: it cannot be held
across a voluntary sleep; it can be acquired in an interrupt thread; if
the lock is held by a writer then the priority of any threads that block
on the lock will be lent to the owner; the simple case lock operations all
are done in a single atomic op. It also shares some similiarities
with sx locks: it supports reader/writer semantics (multiple readers,
but single writers); readers are allowed to recurse, but writers are not.
We can extend this implementation further by either improving algorithms
or adding new functionality, but this should at least give us a base to
work with now.
Reviewed by: arch (in theory)
Tested on: i386 (4 cpu box with a kernel module that used 4 threads
that randomly chose between read locks and write locks
that ran w/o panicing for over a day solid. It usually
panic'd within a few seconds when there were bugs during
testing. :) The kernel module source is available on
request.)
each turnstile. Also, allow for the owner thread pointer of a turnstile
to be NULL. This is needed for the upcoming reader/writer lock
implementation.
- Add a new ddb command 'show turnstile' that will look up the turnstile
associated with the given lock argument and display useful information
like the list of threads blocked on each queue, etc. If there isn't an
active turnstile for a lock at the specified address, then the function
will see if there is an active turnstile at the specified address and
display info about it if so.
- Adjust the mutex code to handle the turnstile API changes.
Tested on: i386 (all), alpha, amd64, sparc64 (1 and 3)
argument and looks for a sleep queue associated with that wait channel.
If it finds one it will display information such as the list of threads
sleeping on that queue. If it can't find a sleep queue for that wait
channel, then it will see if that address matches any of the active
sleep queues. If so, it will display information about the sleepq at the
specified address.
sysctl then it will clear the KTR buffer. Note that if you have active
KTR traces at the same time as a clear operation the behavior is undefined,
though it shouldn't panic.
