Commit Graph

244 Commits

Author SHA1 Message Date
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
John Baldwin
c6a37e8413 Divorce critical sections from spinlocks. Critical sections as denoted by
critical_enter() and critical_exit() are now solely a mechanism for
deferring kernel preemptions.  They no longer have any affect on
interrupts.  This means that standalone critical sections are now very
cheap as they are simply unlocked integer increments and decrements for the
common case.

Spin mutexes now use a separate KPI implemented in MD code: spinlock_enter()
and spinlock_exit().  This KPI is responsible for providing whatever MD
guarantees are needed to ensure that a thread holding a spin lock won't
be preempted by any other code that will try to lock the same lock.  For
now all archs continue to block interrupts in a "spinlock section" as they
did formerly in all critical sections.  Note that I've also taken this
opportunity to push a few things into MD code rather than MI.  For example,
critical_fork_exit() no longer exists.  Instead, MD code ensures that new
threads have the correct state when they are created.  Also, we no longer
try to fixup the idlethreads for APs in MI code.  Instead, each arch sets
the initial curthread and adjusts the state of the idle thread it borrows
in order to perform the initial context switch.

This change is largely a big NOP, but the cleaner separation it provides
will allow for more efficient alternative locking schemes in other parts
of the kernel (bare critical sections rather than per-CPU spin mutexes
for per-CPU data for example).

Reviewed by:	grehan, cognet, arch@, others
Tested on:	i386, alpha, sparc64, powerpc, arm, possibly more
2005-04-04 21:53:56 +00:00
Pawel Jakub Dawidek
c78941e69e Add ki_jid field to the kinfo_proc structure and store jail ID there.
Reviewed by:	gad
MFC after:	3 days
2005-03-20 10:35:23 +00:00
Poul-Henning Kamp
572b4402d1 In stange circumstances we may end up being the last reference to a
session in tprintf().   SESSRELE() needs to properly dispose of the
sessions mutex.

Add sessrele() which does the proper cleanup and have SESSRELE() call it.

Use SESSRELE also in pgdelete().

Found by:	Coverity (ID:526)
2005-03-17 08:44:41 +00:00
Pawel Jakub Dawidek
cefcecbefd Function jailed() looks into ucred strcture, so be sure ucred is not NULL.
Reviewed by:	rwatson
MFC after:	1 week
2005-03-12 14:31:04 +00:00
Pawel Jakub Dawidek
d079d0a0d2 Clean up a bit.
Reviewed by:	rwatson
MFC after:	1 week
2005-03-12 14:28:34 +00:00
Poul-Henning Kamp
0c898376fa Make a bunch of SYSCTL_NODEs static. 2005-02-10 12:15:49 +00:00
Warner Losh
9454b2d864 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 23:35:40 +00:00
David Schultz
1eecfae3e5 Axe a.out core dump support. Neither older gdb binaries nor current
bfd sources understand the present format.
2004-11-27 06:46:59 +00:00
David Schultz
6db36923ad Remove local definitions of RANGEOF() and use __rangeof() instead.
Also remove a few bogus casts.
2004-11-20 23:00:59 +00:00
David Schultz
8b059651ba Malloc p_stats instead of putting it in the U area. We should consider
simply embedding it in struct proc.

Reviewed by:	arch@
2004-11-20 02:28:48 +00:00
Julian Elischer
9b036bdf5a Remove duplicate line. 2004-10-10 05:07:43 +00:00
John Baldwin
78c85e8dfc Rework how we store process times in the kernel such that we always store
the raw values including for child process statistics and only compute the
system and user timevals on demand.

- Fix the various kern_wait() syscall wrappers to only pass in a rusage
  pointer if they are going to use the result.
- Add a kern_getrusage() function for the ABI syscalls to use so that they
  don't have to play stackgap games to call getrusage().
- Fix the svr4_sys_times() syscall to just call calcru() to calculate the
  times it needs rather than calling getrusage() twice with associated
  stackgap, etc.
- Add a new rusage_ext structure to store raw time stats such as tick counts
  for user, system, and interrupt time as well as a bintime of the total
  runtime.  A new p_rux field in struct proc replaces the same inline fields
  from struct proc (i.e. p_[isu]ticks, p_[isu]u, and p_runtime).  A new p_crux
  field in struct proc contains the "raw" child time usage statistics.
  ruadd() has been changed to handle adding the associated rusage_ext
  structures as well as the values in rusage.  Effectively, the values in
  rusage_ext replace the ru_utime and ru_stime values in struct rusage.  These
  two fields in struct rusage are no longer used in the kernel.
- calcru() has been split into a static worker function calcru1() that
  calculates appropriate timevals for user and system time as well as updating
  the rux_[isu]u fields of a passed in rusage_ext structure.  calcru() uses a
  copy of the process' p_rux structure to compute the timevals after updating
  the runtime appropriately if any of the threads in that process are
  currently executing.  It also now only locks sched_lock internally while
  doing the rux_runtime fixup.  calcru() now only requires the caller to
  hold the proc lock and calcru1() only requires the proc lock internally.
  calcru() also no longer allows callers to ask for an interrupt timeval
  since none of them actually did.
- calcru() now correctly handles threads executing on other CPUs.
- A new calccru() function computes the child system and user timevals by
  calling calcru1() on p_crux.  Note that this means that any code that wants
  child times must now call this function rather than reading from p_cru
  directly.  This function also requires the proc lock.
- This finishes the locking for rusage and friends so some of the Giant locks
  in exit1() and kern_wait() are now gone.
- The locking in ttyinfo() has been tweaked so that a shared lock of the
  proctree lock is used to protect the process group rather than the process
  group lock.  By holding this lock until the end of the function we now
  ensure that the process/thread that we pick to dump info about will no
  longer vanish while we are trying to output its info to the console.

Submitted by:	bde (mostly)
MFC after:	1 month
2004-10-05 18:51:11 +00:00
David Schultz
8daa8c602a The zone from which proc structures are allocated is marked
UMA_ZONE_NOFREE to guarantee type stability, so proc_fini() should
never be called.  Move an assertion from proc_fini() to proc_dtor()
and garbage-collect the rest of the unreachable code.  I have retained
vm_proc_dispose(), since I consider its disuse a bug.
2004-09-19 18:34:17 +00:00
Julian Elischer
ed062c8d66 Refactor a bunch of scheduler code to give basically the same behaviour
but with slightly cleaned up interfaces.

The KSE structure has become the same as the "per thread scheduler
private data" structure. In order to not make the diffs too great
one is #defined as the other at this time.

The KSE (or td_sched) structure is  now allocated per thread and has no
allocation code of its own.

Concurrency for a KSEGRP is now kept track of via a simple pair of counters
rather than using KSE structures as tokens.

Since the KSE structure is different in each scheduler, kern_switch.c
is now included at the end of each scheduler. Nothing outside the
scheduler knows the contents of the KSE (aka td_sched) structure.

The fields in the ksegrp structure that are to do with the scheduler's
queueing mechanisms are now moved to the kg_sched structure.
(per ksegrp scheduler private data structure). In other words how the
scheduler queues and keeps track of threads is no-one's business except
the scheduler's. This should allow people to write experimental
schedulers with completely different internal structuring.

A scheduler call sched_set_concurrency(kg, N) has been added that
notifies teh scheduler that no more than N threads from that ksegrp
should be allowed to be on concurrently scheduled. This is also
used to enforce 'fainess' at this time so that a ksegrp with
10000 threads can not swamp a the run queue and force out a process
with 1 thread, since the current code will not set the concurrency above
NCPU, and both schedulers will not allow more than that many
onto the system run queue at a time. Each scheduler should eventualy develop
their own methods to do this now that they are effectively separated.

Rejig libthr's kernel interface to follow the same code paths as
linkse for scope system threads. This has slightly hurt libthr's performance
but I will work to recover as much of it as I can.

Thread exit code has been cleaned up greatly.
exit and exec code now transitions a process back to
'standard non-threaded mode' before taking the next step.
Reviewed by:	scottl, peter
MFC after:	1 week
2004-09-05 02:09:54 +00:00
Robert Watson
6cbea71c82 Cause pfind() not to return processes in the PRS_NEW state. As a result,
threads consuming the result of pfind() will not need to check for a NULL
credential pointer or other signs of an incompletely created process.
However, this also means that pfind() cannot be used to test for the
existence or find such a process.  Annotate pfind() to indicate that this
is the case.  A review of curent consumers seems to indicate that this is
not a problem for any of them.  This closes a number of race conditions
that could result in NULL pointer dereferences and related failure modes.
Other related races continue to exist, especially during iteration of the
allproc list without due caution.

Discussed with:	tjr, green
2004-08-14 17:15:16 +00:00
Julian Elischer
332e72ddb7 Remove typos on KASSERT messages. 2004-08-09 20:13:07 +00:00
Brian Feldman
b23f72e98a * Add a "how" argument to uma_zone constructors and initialization functions
so that they know whether the allocation is supposed to be able to sleep
  or not.
* Allow uma_zone constructors and initialation functions to return either
  success or error.  Almost all of the ones in the tree currently return
  success unconditionally, but mbuf is a notable exception: the packet
  zone constructor wants to be able to fail if it cannot suballocate an
  mbuf cluster, and the mbuf allocators want to be able to fail in general
  in a MAC kernel if the MAC mbuf initializer fails.  This fixes the
  panics people are seeing when they run out of memory for mbuf clusters.
* Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing
  the default.

Both bmilekic and jeff have reviewed the changes made to make failable
zone allocations work.
2004-08-02 00:18:36 +00:00
Pawel Jakub Dawidek
cebabef04f Fill some informations about zombie processes as well.
Before this change every zombie process were reported as an owner of PID 0 in
ps(1) output.

Reviewed by:	julian
2004-07-29 20:27:59 +00:00
Garance A Drosehn
7638fa19a7 Fill in the values for the ki_tid and ki_numthreads which have been
added to kproc_info.

PR:		bin/65803  (a tiny part...)
Submitted by:	Cyrille Lefevre
2004-06-20 22:17:22 +00:00
Garance A Drosehn
99d2ecbc7d Add a call to calcru() to update the kproc_info fields of ki_rusage.ru_utime
and ki_rusage.ru_stime.  This greatly improves the accuracy of those fields.

Suggested by:	bde
2004-06-20 02:03:33 +00:00
Garance A Drosehn
078842c5c9 Fill in the some new fields 'struct kinfo_proc', namely ki_childstime,
ki_childutime, and ki_emul.  Also uses the timevaladd() routine to
correct the calculation of ki_childtime.  That will correct the value
returned when ki_childtime.tv_usec > 1,000,000.

This also implements a new KERN_PROC_GID option for kvm_getprocs().
(there will be a similar update to lib/libkvm/kvm_proc.c)

Submitted by:	Cyrille Lefevre
2004-06-19 14:03:00 +00:00
Poul-Henning Kamp
f3732fd15b Second half of the dev_t cleanup.
The big lines are:
	NODEV -> NULL
	NOUDEV -> NODEV
	udev_t -> dev_t
	udev2dev() -> findcdev()

Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
2004-06-17 17:16:53 +00:00
Julian Elischer
fa88511615 Nice, is a property of a process as a whole..
I mistakenly moved it to the ksegroup when breaking up the process
structure. Put it back in the proc structure.
2004-06-16 00:26:31 +00:00
Poul-Henning Kamp
2195e4207a Reference count struct tty.
Add two new functions: ttyref() and ttyrel().  ttymalloc() creates a struct
tty with a reference count of one.  when ttyrel sees the count go to zero,
struct tty is freed.

Hold references for open ttys and for ttys which are controlling terminal
for sessions.

Until drivers start using ttyrel(), this commit will make no difference.
2004-06-09 09:41:30 +00:00
Poul-Henning Kamp
a59df4e1ee Fix a race in destruction of sessions. 2004-06-09 09:29:08 +00:00
Garance A Drosehn
b8fdc89d79 Implement the new KERN_PROC_RGID option, and also implement the
KERN_PROC_SESSION option which had been previously defined but
never implemented.

PR:		bin/65803  (a very tiny piece of the PR)`
Submitted by:	Cyrille Lefevre
2004-05-22 23:11:44 +00:00
Warner Losh
7f8a436ff2 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core
2004-04-05 21:03:37 +00:00
Pawel Jakub Dawidek
5e2c0c0b0e Remove ps_argsopen check. It is was bogus in the past and was corrected
not quite well by me - if kern.ps_argsopen was set to 0, users weren't
permitted to see arguments of even own processes.
But kern.ps_argsopen is going away, so just remove this check and leave
security checks for p_cansee() function.
2004-04-01 00:08:20 +00:00
Pawel Jakub Dawidek
9cdb62160b Fix information leakage.
Without this fix it is possible to cheat policies like:
- sysctl security.bsd.see_other_[gu]ids=0,
- mac_seeotheruids(4),
- jail(2)
and get full processes list with their arguments.

This problem exists from revision 1.62 of kern_proc.c when it was
introduced.

Reviewed by:	nectar, rwatson.
2004-03-17 13:19:43 +00:00
Don Lewis
47934cef8f Split the mlock() kernel code into two parts, mlock(), which unpacks
the syscall arguments and does the suser() permission check, and
kern_mlock(), which does the resource limit checking and calls
vm_map_wire().  Split munlock() in a similar way.

Enable the RLIMIT_MEMLOCK checking code in kern_mlock().

Replace calls to vslock() and vsunlock() in the sysctl code with
calls to kern_mlock() and kern_munlock() so that the sysctl code
will obey the wired memory limits.

Nuke the vslock() and vsunlock() implementations, which are no
longer used.

Add a member to struct sysctl_req to track the amount of memory
that is wired to handle the request.

Modify sysctl_wire_old_buffer() to return an error if its call to
kern_mlock() fails.  Only wire the minimum of the length specified
in the sysctl request and the length specified in its argument list.
It is recommended that sysctl handlers that use sysctl_wire_old_buffer()
should specify reasonable estimates for the amount of data they
want to return so that only the minimum amount of memory is wired
no matter what length has been specified by the request.

Modify the callers of sysctl_wire_old_buffer() to look for the
error return.

Modify sysctl_old_user to obey the wired buffer length and clean up
its implementation.

Reviewed by:	bms
2004-02-26 00:27:04 +00:00
Daniel Eischen
2648efa621 Add sysctls to allow showing threads for pgrp, tty, uid, ruid,
and pid.
2004-02-22 17:54:32 +00:00
Jeff Roberson
7cf90fb376 - Update the sched api. sched_{add,rem,clock,pctcpu} now all accept a td
argument rather than a kse.
2003-10-16 08:39:15 +00:00
Peter Wemm
25e247af44 The KERN_PROC_PROC sysctl took 4 args in 5.0-REL and 5.1-REL. We need to
accept this for a bit longer.  Requiring the new order of 3 args only
was not very helpful.
2003-10-15 03:11:46 +00:00