Commit Graph

277 Commits

Author SHA1 Message Date
Attilio Rao
f8d9048018 - Add a function (fill_kinfo_aggregate()) which aggregates relevant
members for a kinfo entry on a process-wide system.
- Use the newly introduced function in order to fix cases like
  KERN_PROC_PROC where aggregating stats are broken because they just
  consider the first thread in the pool for each process.
  (Note, additively, that KERN_PROC_PROC is rather inaccurate on
  thread-wide informations like the 'state' of the process.  Such
  informations should maybe be invalidated and being forceably discarded
  by the consumers?).
- Simplify the logic of sysctl_out_proc() and adjust the
  fill_kinfo_thread() accordingly.
- Remove checks on the FIRST_THREAD_IN_PROC() being NULL but add
  assertives.

This patch should fix aggregate statistics for KERN_PROC_PROC.
This is one of the reasons why top doesn't use this option and now it
can be use it safely.
ps, when launched in order to display just processes, now should report
correct cpu utilization percentages and times (as opposed by the old
code).

Reviewed by:	jhb, emaste
Sponsored by:	Sandvine Incorporated
2009-02-18 21:52:13 +00:00
John Baldwin
24f87fdbe8 - Add conditional Giant locking around the vrele() in
sysctl_kern_proc_pathname().
- Mark all the kern.proc.* sysctls as MPSAFE.

Submitted by:	csjp (2)
2009-01-23 22:46:45 +00:00
Konstantin Belousov
22a448c4d9 vm_map_lock_read() does not increment map->timestamp, so we should
compare map->timestamp with saved timestamp after map read lock is
reacquired, not with saved timestamp + 1. The only consequence of the +1
was unconditional lookup of the next map entry, though.

Tested by:	pho
Approved by:	des
MFC after:	2 weeks
2008-12-29 12:45:11 +00:00
Konstantin Belousov
c7462f4387 Reference the vmspace of the process being inspected by procfs, linprocfs
and sysctl kern_proc_vmmap handlers.

Reported and tested by:	pho
Reviewed by:	rwatson, des
MFC after:	1 week
2008-12-12 12:12:36 +00:00
Konstantin Belousov
118d0afa28 Do drop vm map lock earlier in the sysctl_kern_proc_vmmap(), to avoid
locking a vnode while having vm map locked.

Reported and tested by:	pho
MFC after:	1 week
2008-12-08 12:29:30 +00:00
Konstantin Belousov
aeb325719a Several threads in a process may do vfork() simultaneously. Then, all
parent threads sleep on the parent' struct proc until corresponding
child releases the vmspace. Each sleep is interlocked with proc mutex of
the child, that triggers assertion in the sleepq_add(). The assertion
requires that at any time, all simultaneous sleepers for the channel use
the same interlock.

Silent the assertion by using conditional variable allocated in the
child. Broadcast the variable event on exec() and exit().

Since struct proc * sleep wait channel is overloaded for several
unrelated events, I was unable to remove wakeups from the places where
cv_broadcast() is added, except exec().

Reported and tested by:	ganbold
Suggested and reviewed by:	jhb
MFC after:	2 week
2008-12-05 20:50:24 +00:00
Peter Wemm
43151ee6cf Merge user/peter/kinfo branch as of r185547 into head.
This changes struct kinfo_filedesc and kinfo_vmentry such that they are
same on both 32 and 64 bit platforms like i386/amd64 and won't require
sysctl wrapping.

Two new OIDs are assigned.  The old ones are available under
COMPAT_FREEBSD7 - but it isn't that simple.  The superceded interface
was never actually released on 7.x.

The other main change is to pack the data passed to userland via the
sysctl.  kf_structsize and kve_structsize are reduced for the copyout.
If you have a process with 100,000+ sockets open, the unpacked records
require a 132MB+ copyout.  With packing, it is "only" ~35MB.  (Still
seriously unpleasant, but not quite as devastating).  A similar problem
exists for the vmentry structure - have lots and lots of shared libraries
and small mmaps and its copyout gets expensive too.

My immediate problem is valgrind.  It traditionally achieves this
functionality by parsing procfs output, in a packed format.  Secondly, when
tracing 32 bit binaries on amd64 under valgrind, it uses a cross compiled
32 bit binary which ran directly into the differing data structures in 32
vs 64 bit mode.  (valgrind uses this to track file descriptor operations
and this therefore affected every single 32 bit binary)

I've added two utility functions to libutil to unpack the structures into
a fixed record length and to make it a little more convenient to use.
2008-12-02 06:50:26 +00:00
Pawel Jakub Dawidek
1ba4a712dd Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes.
This bring huge amount of changes, I'll enumerate only user-visible changes:

- Delegated Administration

	Allows regular users to perform ZFS operations, like file system
	creation, snapshot creation, etc.

- L2ARC

	Level 2 cache for ZFS - allows to use additional disks for cache.
	Huge performance improvements mostly for random read of mostly
	static content.

- slog

	Allow to use additional disks for ZFS Intent Log to speed up
	operations like fsync(2).

- vfs.zfs.super_owner

	Allows regular users to perform privileged operations on files stored
	on ZFS file systems owned by him. Very careful with this one.

- chflags(2)

	Not all the flags are supported. This still needs work.

- ZFSBoot

	Support to boot off of ZFS pool. Not finished, AFAIK.

	Submitted by:	dfr

- Snapshot properties

- New failure modes

	Before if write requested failed, system paniced. Now one
	can select from one of three failure modes:
	- panic - panic on write error
	- wait - wait for disk to reappear
	- continue - serve read requests if possible, block write requests

- Refquota, refreservation properties

	Just quota and reservation properties, but don't count space consumed
	by children file systems, clones and snapshots.

- Sparse volumes

	ZVOLs that don't reserve space in the pool.

- External attributes

	Compatible with extattr(2).

- NFSv4-ACLs

	Not sure about the status, might not be complete yet.

	Submitted by:	trasz

- Creation-time properties

- Regression tests for zpool(8) command.

Obtained from:	OpenSolaris
2008-11-17 20:49:29 +00:00
John Baldwin
2ff47c5f18 Remove unnecessary locking around vn_fullpath(). The vnode lock for the
vnode in question does not need to be held.  All the data structures used
during the name lookup are protected by the global name cache lock.
Instead, the caller merely needs to ensure a reference is held on the
vnode (such as vhold()) to keep it from being freed.

In the case of procfs' <pid>/file entry, grab the process lock while we
gain a new reference (via vhold()) on p_textvp to fully close races with
execve(2).

For the kern.proc.vmmap sysctl handler, use a shared vnode lock around
the call to VOP_GETATTR() rather than an exclusive lock.

MFC after:	1 month
2008-11-04 19:04:01 +00:00
Peter Wemm
7a9c4d2409 Add three extra to the kinfo_proc_vmmap data. kve_offset - the offset
within an object that a mapping refers to.  fileid and fsid are inode/dev
for vnodes.  (Linux procfs has these and valgrind is really unhappy
without them.)  I believe I didn't change the size of the struct.
2008-10-31 05:43:19 +00:00
Dag-Erling Smørgrav
1ede983cc9 Retire the MALLOC and FREE macros. They are an abomination unto style(9).
MFC after:	3 months
2008-10-23 15:53:51 +00:00
Ed Schouten
42ff2756c7 Fix minor TTY API inconsistency.
Unlike tty_rel_gone() and tty_rel_sess(), the tty_rel_pgrp() routine
does not unlock the TTY. I once had the idea to make the code call
tty_rel_pgrp() and tty_rel_sess(), picking up the TTY lock once. This
turned out a little harder than I expected, so this is how it works now.

It's a lot easier if we just let tty_rel_pgrp() unlock the TTY, because
the other routines do this anyway.
2008-09-16 14:57:23 +00:00
Kevin Lo
f308bddd3f If the process id specified is invalid, the system call returns ESRCH 2008-09-04 10:44:33 +00:00
Ed Schouten
bc093719ca Integrate the new MPSAFE TTY layer to the FreeBSD operating system.
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:

- Improved driver model:

  The old TTY layer has a driver model that is not abstract enough to
  make it friendly to use. A good example is the output path, where the
  device drivers directly access the output buffers. This means that an
  in-kernel PPP implementation must always convert network buffers into
  TTY buffers.

  If a PPP implementation would be built on top of the new TTY layer
  (still needs a hooks layer, though), it would allow the PPP
  implementation to directly hand the data to the TTY driver.

- Improved hotplugging:

  With the old TTY layer, it isn't entirely safe to destroy TTY's from
  the system. This implementation has a two-step destructing design,
  where the driver first abandons the TTY. After all threads have left
  the TTY, the TTY layer calls a routine in the driver, which can be
  used to free resources (unit numbers, etc).

  The pts(4) driver also implements this feature, which means
  posix_openpt() will now return PTY's that are created on the fly.

- Improved performance:

  One of the major improvements is the per-TTY mutex, which is expected
  to improve scalability when compared to the old Giant locking.
  Another change is the unbuffered copying to userspace, which is both
  used on TTY device nodes and PTY masters.

Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.

Obtained from:		//depot/projects/mpsafetty/...
Approved by:		philip (ex-mentor)
Discussed:		on the lists, at BSDCan, at the DevSummit
Sponsored by:		Snow B.V., the Netherlands
dcons(4) fixed by:	kan
2008-08-20 08:31:58 +00:00
Konstantin Belousov
58e8af1bf5 Call pargs_drop() unconditionally in do_execve(), the function correctly
handles the NULL argument.
Make pargs_free() static.

MFC after:	1 week
2008-07-25 11:55:32 +00:00
John Birrell
5d217f173c Add DTrace 'proc' provider probes using the Statically Defined Trace
(sdt) mechanism.
2008-05-24 06:22:16 +00:00
Jeff Roberson
374ae2a393 - Relax requirements for p_numthreads, p_threads, p_swtick, and p_nice from
requiring the per-process spinlock to only requiring the process lock.
 - Reflect these changes in the proc.h documentation and consumers throughout
   the kernel.  This is a substantial reduction in locking cost for these
   fields and was made possible by recent changes to threading support.
2008-03-19 06:19:01 +00:00
Jeff Roberson
6617724c5f Remove kernel support for M:N threading.
While the KSE project was quite successful in bringing threading to
FreeBSD, the M:N approach taken by the kse library was never developed
to its full potential.  Backwards compatibility will be provided via
libmap.conf for dynamically linked binaries and static binaries will
be broken.
2008-03-12 10:12:01 +00:00
Robert Watson
d92909c1d4 Don't zero td_runtime when billing thread CPU usage to the process;
maintain a separate td_incruntime to hold unbilled CPU usage for
the thread that has the previous properties of td_runtime.

When thread information is requested using the thread monitoring
sysctls, export thread td_runtime instead of process rusage runtime
in kinfo_proc.

This restores the display of individual ithread and other kernel
thread CPU usage since inception in ps -H and top -SH, as well for
libthr user threads, valuable debugging information lost with the
move to try kthreads since they are no longer independent processes.

There is universal agreement that we should rewrite the process and
thread export sysctls, but this commit gets things going a bit
better in the mean time.  Likewise, there are resevations about the
continued validity of statclock given the speed of modern processors.

Reviewed by:		attilio, emaste, jhb, julian
2008-01-10 22:11:20 +00:00
Attilio Rao
cb05b60a89 vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.

Manpage and FreeBSD_version will be updated through further commits.

As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.

Tested by:	Diego Sardina <siarodx at gmail dot com>,
		Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
Robert Watson
0417fe5421 Return ESRCH when a kernel stack is queried on a process in execve() --
p_candebug() will return EAGAIN which, if the other process never
leaves execve(), will result in the sysctl spinning and never returning
to userspace.  Processes should always eventually leave execve(), but
spinning in kernel while we wait is bad for countless reasons, and
particularly harmful if execve() itself is deadlocked.

Possibly we should return another error, or return a marker indicating
the thread is in execve() so it can be reported that way in userspace.

Reported by:	kris
2007-12-27 22:44:01 +00:00
Robert Watson
63d79c4fd6 Check for P_WEXIT before PHOLD() on a process in kstack and vm query
sysctls, as PHOLD() asserts !P_WEXIT.

Reported by:	Michael Plass <mfp49_freebsd at plass-family dot net>
2007-12-09 17:22:27 +00:00
Robert Watson
1cc8c45c54 Add another new sysctl in support of the forthcoming procstat(1) to
support its -k argument:

kern.proc.kstack - dump the kernel stack of a process, if debugging
  is permitted.

This sysctl is present if either "options DDB" or "options STACK" is
compiled into the kernel.  Having support for tracing the kernel
stacks of processes from user space makes it much easier to debug
(or understand) specific wmesg's while avoiding the need to enter
DDB in order to determine the path by which a process came to be
blocked on a particular wait channel or lock.
2007-12-02 21:52:18 +00:00
Robert Watson
cc43c38c87 Add two new sysctls in support of the forthcoming procstat(1) to support
its -f and -v arguments:

kern.proc.filedesc - dump file descriptor information for a process, if
  debugging is permitted, including socket addresses, open flags, file
  offsets, file paths, etc.

kern.proc.vmmap - dump virtual memory mapping information for a process,
  if debugging is permitted, including layout and information on
  underlying objects, such as the type of object and path.

These provide a superset of the information historically available
through the now-deprecated procfs(4), and are intended to be exported
in an ABI-robust form.
2007-12-02 10:10:27 +00:00
Robert Watson
965b55e2b4 Test that p_textvp is non-NULL be dereferencing, as no executable vnode is
set for kernel processes.

Reported by:	Skip Ford <skip at menantico dot com>
MFC after:	3 days
2007-11-20 18:03:09 +00:00
Randall Stewart
4a62a3e556 Adds an event handler for:
- process_ctor,dtor, init and fini
  - thread_ctor,dtor, init and fini
This allows the ability to add on additional things
during construction/destruction of threads and processes.

Reviewed by:	rwatson
2007-11-15 13:28:54 +00:00
Konstantin Belousov
89b57fcf01 Fix for the panic("vm_thread_new: kstack allocation failed") and
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.

As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.

The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).

In collaboration with:	Peter Holm
Reviewed by:	jhb
2007-11-05 11:36:16 +00:00
Jeff Roberson
54b0e65f84 - Redefine p_swtime and td_slptime as p_swtick and td_slptick. This
changes the units from seconds to the value of 'ticks' when swapped
   in/out.  ULE does not have a periodic timer that scans all threads in
   the system and as such maintaining a per-second counter is difficult.
 - Change computations requiring the unit in seconds to subtract ticks
   and divide by hz.  This does make the wraparound condition hz times
   more frequent but this is still in the range of several months to
   years and the adverse effects are minimal.

Approved by:	re
2007-09-21 04:10:23 +00:00
Jeff Roberson
b61ce5b0e6 - Move all of the PS_ flags into either p_flag or td_flags.
- p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or
   previously the sched_lock.  These bugs have existed for some time.
 - Allow swapout to try each thread in a process individually and then
   swapin the whole process if any of these fail.  This allows us to move
   most scheduler related swap flags into td_flags.
 - Keep ki_sflag for backwards compat but change all in source tools to
   use the new and more correct location of P_INMEM.

Reported by:	pho
Reviewed by:	attilio, kib
Approved by:	re (kensmith)
2007-09-17 05:31:39 +00:00
Attilio Rao
a1fe14bc33 rufetch and calcru sometimes should be called atomically together.
This patch fixes places where they should be called atomically changing
their locking requirements (both assume per-proc spinlock held) and
introducing rufetchcalc which wrappers both calls to be performed in
atomic way.

Reviewed by: jeff
Approved by: jeff (mentor)
2007-06-09 21:48:44 +00:00
Jeff Roberson
982d11f836 Commit 14/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
   sychronization.
 - Use the per-process spinlock rather than the sched_lock for per-process
   scheduling synchronization.

Tested by:      kris, current@
Tested on:      i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
Jeff Roberson
1c4bcd050a - Move rusage from being per-process in struct pstats to per-thread in
td_ru.  This removes the requirement for per-process synchronization in
   statclock() and mi_switch().  This was previously supported by
   sched_lock which is going away.  All modifications to rusage are now
   done in the context of the owning thread.  reads proceed without locks.
 - Aggregate exiting threads rusage in thread_exit() such that the exiting
   thread's rusage is not lost.
 - Provide a new routine, rufetch() to fetch an aggregate of all rusage
   structures from all threads in a process.  This routine must be used
   in any place requiring a rusage from a process prior to it's exit.  The
   exited process's rusage is still available via p_ru.
 - Aggregate tick statistics only on demand via rufetch() or when a thread
   exits.  Tick statistics are kept in the thread and protected by sched_lock
   until it exits.

Initial patch by:	attilio
Reviewed by:		attilio, bde (some objections), arch (mostly silent)
2007-06-01 01:12:45 +00:00
Ed Maste
13b762a304 Stop setting ki_ocomm (thread name) to the proc name by default, as nothing
in the base system relies on this any longer.
2007-03-23 04:01:08 +00:00
Julian Elischer
ad1e7d285a Threading cleanup.. part 2 of several.
Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs.  Libpthread processes will already
do this to some extent and libthr processes already disable it.

Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.

The ULE scheduler compiles again but I have no idea if it works.

The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.

Tested by David Xu, and Dan Eischen using libthr and libpthread.
2006-12-06 06:34:57 +00:00
John Birrell
8460a577a4 Make KSE a kernel option, turned on by default in all GENERIC
kernel configs except sun4v (which doesn't process signals properly
with KSE).

Reviewed by:	davidxu@
2006-10-26 21:42:22 +00:00
Pawel Jakub Dawidek
2342d5216e Remove duplicated $FreeBSD$. 2006-09-30 16:33:29 +00:00
Martin Blapp
8be563721a Move Giant up even further since P_CONTROLT isn't really fully locked
yet (p_flag is, but P_CONTROLT isn't really).

Submitted by:	jhb
2006-09-27 16:42:10 +00:00
Martin Blapp
45e6819160 Protect enterpgrp() against another tty/proc race case until the tty locking work
has been fixed.

MFC after:	1 week
2006-09-23 17:35:24 +00:00
Martin Blapp
d7b167b57b Fix races between tty.c and sessrele() / doenterpgrp() / leavepgrp(). The tty
code is still under giant lock, but the session/pgrp release code just used
proctree_locks. This explains why moving the proctree_lock in sys/kern/tty.c
rev. 1.258 did fix the panics in our SMP systems.

This should also fix some race panics with revoked ttys.

Reviewed by:	jhb
MFC after:	1 week
2006-09-19 19:25:11 +00:00
Poul-Henning Kamp
e8444a7e6f CPU time accounting speedup (step 2)
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
2006-02-11 09:33:07 +00:00
Poul-Henning Kamp
5b1a8eb397 Modify the way we account for CPU time spent (step 1)
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.
2006-02-07 21:22:02 +00:00
Julian Elischer
11f4763dd4 Return the thread name in the kinfo_proc structure.
Also correct the comment describing what the value is.
2006-01-18 20:27:43 +00:00
Juli Mallett
b241b0a239 Since p_cansee will end up dereferencing p_ucred, don't check for p_ucred
equal to NULL several times later.  p_ucred "should probably not" be NULL
if the process isn't PRS_NEW anyway.  This is strongly reinforced by the fact
that we don't see frequent crashes here.  Remove the checks after p_cansee and
add a KASSERT right before it.

Found by:	Coverity Prevent (tm)

Also trim one nearby trailing space.
2006-01-17 20:25:01 +00:00
David Xu
3357835a46 Add code to report zombie state.
PR: threads/91044
MFC after: 3 days
2005-12-29 13:00:42 +00:00
Robert Watson
2c255e9df6 Moderate rewrite of kernel ktrace code to attempt to generally improve
reliability when tracing fast-moving processes or writing traces to
slow file systems by avoiding unbounded queueuing and dropped records.
Record loss was previously possible when the global pool of records
become depleted as a result of record generation outstripping record
commit, which occurred quickly in many common situations.

These changes partially restore the 4.x model of committing ktrace
records at the point of trace generation (synchronous), but maintain
the 5.x deferred record commit behavior (asynchronous) for situations
where entering VFS and sleeping is not possible (i.e., in the
scheduler).  Records are now queued per-process as opposed to
globally, with processes responsible for committing records from their
own context as required.

- Eliminate the ktrace worker thread and global record queue, as they
  are no longer used.  Keep the global free record list, as records
  are still used.

- Add a per-process record queue, which will hold any asynchronously
  generated records, such as from context switches.  This replaces the
  global queue as the place to submit asynchronous records to.

- When a record is committed asynchronously, simply queue it to the
  process.

- When a record is committed synchronously, first drain any pending
  per-process records in order to maintain ordering as best we can.
  Currently ordering between competing threads is provided via a global
  ktrace_sx, but a per-process flag or lock may be desirable in the
  future.

- When a process returns to user space following a system call, trap,
  signal delivery, etc, flush any pending records.

- When a process exits, flush any pending records.

- Assert on process tear-down that there are no pending records.

- Slightly abstract the notion of being "in ktrace", which is used to
  prevent the recursive generation of records, as well as generating
  traces for ktrace events.

Future work here might look at changing the set of events marked for
synchronous and asynchronous record generation, re-balancing queue
depth, timeliness of commit to disk, and so on.  I.e., performing a
drain every (n) records.

MFC after:	1 month
Discussed with:	jhb
Requested by:	Marc Olzheim <marcolz at stack dot nl>
2005-11-13 13:27:44 +00:00
David Xu
ebceaf6dc7 Add support for queueing SIGCHLD same as other UNIX systems did.
For each child process whose status has been changed, a SIGCHLD instance
is queued, if the signal is stilling pending, and process changed status
several times, signal information is updated to reflect latest process
status. If wait() returns because the status of a child process is
available, pending SIGCHLD signal associated with the child process is
discarded. Any other pending SIGCHLD signals remain pending.

The signal information is allocated at the same time when proc structure
is allocated, if process signal queue is fully filled or there is a memory
shortage, it can still send the signal to process.

There is a booting time tunable kern.sigqueue.queue_sigchild which
can control the behavior, setting it to zero disables the SIGCHLD queueing
feature, the tunable will be removed if the function is proved that it is
stable enough.

Tested on: i386 (SMP and UP)
2005-11-08 09:09:26 +00:00
John Baldwin
f55ab99409 Document in #ifdef notnow code the actions that proc_fini would need to
take if struct procs were actually freed.
2005-10-24 20:15:23 +00:00
Don Lewis
5032ff8197 Always wire the sysctl output buffer in sysctl_kern_proc() before
calling sysctl_out_proc().  -- fix from jhb

Move the code in fill_kinfo_thread() that gathers data from struct proc
into the new function fill_kinfo_proc_only().

Change all callers of fill_kinfo_thread() to call both
fill_kinfo_proc_only() and fill_kinfo() thread.  When gathering
data from a multi-threaded process, fill_kinfo_proc_only() only needs
to be called once.

Grab sched_lock before accessing the process thread list or calling
fill_kinfo_thread().

PR:		kern/84684
MFC after:	3 days
2005-10-02 23:27:56 +00:00
John Baldwin
55b4a5ae0d Use the refcount API to implement reference counts on process argument
structures rather than using a global mutex to protect the reference
counts.

Tested on:	i386, alpha, sparc64
2005-09-27 18:03:15 +00:00
David Schultz
fe769cdd95 Add a sysctl that returns the full path of a process' text file.
This information is needed by things like `gdb -p' and Sun's javac,
and previously it could only be obtained via procfs
2005-04-18 02:10:37 +00:00