Commit Graph

104 Commits

Author SHA1 Message Date
jhb
c7ac62aecd Fix some locking nits with the p_state field of struct proc:
- Hold the proc lock while changing the state from PRS_NEW to PRS_NORMAL
  in fork to honor the locking requirements.  While here, expand the scope
  of the PROC_LOCK() on the new process (p2) to avoid some LORs.  Previously
  the code was locking the new child process (p2) after it had locked the
  parent process (p1).  However, when locking two processes, the safe order
  is to lock the child first, then the parent.
- Fix various places that were checking p_state against PRS_NEW without
  having the process locked to use PROC_LOCK().  Every place was already
  locking the process, just after the PRS_NEW check.
- Remove or reduce the use of PROC_SLOCK() for places that were checking
  p_state against PRS_NEW.  The PROC_LOCK() alone is sufficient for reading
  the current state.
- Reorder fill_kinfo_proc() slightly so it only acquires PROC_SLOCK() once.

MFC after:	1 week
2011-03-24 18:40:11 +00:00
jmallett
77919e089a Use CPU_FOREACH rather than expecting CPUs 0 through mp_ncpus-1 to be present.
Don't micro-optimize the uniprocessor case; use the same loop there.

Submitted by:	Bhanu Prakash
Reviewed by:	kib, jhb
2011-02-12 02:10:08 +00:00
kib
4f8260e700 Move repeated MAXSLP definition from machine/vmparam.h to sys/vmmeter.h.
Update the outdated comments describing MAXSLP and the process
selection algorithm for swap out.

Comments wording and reviewed by:	alc
2011-01-09 12:50:44 +00:00
jhb
44220d7e1e Add a new type of VM object: OBJT_SG. An OBJT_SG object is very similar to
a device pager (OBJT_DEVICE) object in that it uses fictitious pages to
provide aliases to other memory addresses.  The primary difference is that
it uses an sglist(9) to determine the physical addresses for a given offset
into the object instead of invoking the d_mmap() method in a device driver.

Reviewed by:	alc
Approved by:	re (kensmith)
MFC after:	2 weeks
2009-07-24 13:50:29 +00:00
jhb
a9601871c9 - Mark all standalone INT/LONG/QUAD sysctl's MPSAFE. This is done
inside the SYSCTL() macros and thus does not need to be done for
  all of the nodes scattered across the source tree.
- Mark the name-cache related sysctl's (including debug.hashstat.*) MPSAFE.
- Mark vm.loadavg MPSAFE.
- Remove GIANT_REQUIRED from vmtotal() (everything in this routine already
  has sufficient locking) and mark vm.vmtotal MPSAFE.
- Mark the vm.stats.(sys|vm).* sysctls MPSAFE.
2009-01-23 22:49:23 +00:00
julian
0592958505 A bunch of formatting fixes brough to light by, or created by the Vimage commit
a few days ago.
2008-08-20 01:05:56 +00:00
jeff
46f09d5bc3 - 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
3b1acbdce2 - Pass the priority argument from *sleep() into sleepq and down into
sched_sleep().  This removes extra thread_lock() acquisition and
   allows the scheduler to decide what to do with the static boost.
 - Change the priority arguments to cv_* to match sleepq/msleep/etc.
   where 0 means no priority change.  Catch -1 in cv_broadcastpri() and
   convert it to 0 for now.
 - Set a flag when sleeping in a way that is compatible with swapping
   since direct priority comparisons are meaningless now.
 - Add a sysctl to ule, kern.sched.static_boost, that defaults to on which
   controls the boost behavior.  Turning it off gives better performance
   in some workloads but needs more investigation.
 - While we're modifying sleepq, change signal and broadcast to both
   return with the lock held as the lock was held on enter.

Reviewed by:	jhb, peter
2008-03-12 06:31:06 +00:00
alc
215153274b Add a counter for the total number of pages cached and support for
reporting the value of this counter in the program "vmstat".

Approved by:	re (rwatson)
2007-07-27 20:01:22 +00:00
alc
db9dd359b6 Eliminate dead code.
Approved by:	re (hrs)
2007-07-12 22:23:28 +00:00
jeff
91d1501790 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
attilio
7dd8ed88a9 Revert VMCNT_* operations introduction.
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.

Requested by: alc
Approved by: jeff (mentor)
2007-05-31 22:52:15 +00:00
jeff
e1996cb960 - define and use VMCNT_{GET,SET,ADD,SUB,PTR} macros for manipulating
vmcnts.  This can be used to abstract away pcpu details but also changes
   to use atomics for all counters now.  This means sched lock is no longer
   responsible for protecting counts in the switch routines.

Contributed by:		Attilio Rao <attilio@FreeBSD.org>
2007-05-18 07:10:50 +00:00
ru
825e064fde Remove a redundant pointer-type variable. 2006-11-20 08:33:55 +00:00
ru
e58221ee6f When counting vm totals, skip unreferenced objects, including
vnodes representing mounted file systems.

Reviewed by:	alc
MFC after:	3 days
2006-11-20 00:16:00 +00:00
alc
b5b274360a Retire debug.mpsafevm. None of the architectures supported in CVS require
it any longer.
2006-07-21 23:22:49 +00:00
alc
e79c83b068 Set debug.mpsafevm to true on PowerPC. (Now, by default, all architectures
in CVS have debug.mpsafevm set to true.)

Tested by: grehan@
2006-07-10 07:08:05 +00:00
alc
3fe756d726 Enable debug.mpsafevm on arm by default.
Tested by: cognet@
2006-06-10 05:29:37 +00:00
tegge
0d5f191162 Close race between vmspace_exitfree() and exit1() and races between
vmspace_exitfree() and vmspace_free() which could result in the same
vmspace being freed twice.

Factor out part of exit1() into new function vmspace_exit().  Attach
to vmspace0 to allow old vmspace to be freed earlier.

Add new function, vmspace_acquire_ref(), for obtaining a vmspace
reference for a vmspace belonging to another process.  Avoid changing
vmspace refcount from 0 to 1 since that could also lead to the same
vmspace being freed twice.

Change vmtotal() and swapout_procs() to use vmspace_acquire_ref().

Reviewed by:	alc
2006-05-29 21:28:56 +00:00
marcel
9be5f7d46a Enable debug_mpsafevm on ia64 due to the severe functional regression
caused by recent locking changes when it's off. Revert the logic to
trim down the conditional.

Clued-in by: alc@
2005-05-08 23:56:16 +00:00
jhb
e62b86cdc5 Tidy vcnt() by moving a duplicated line above #ifdef and removing a useless
variable.
2005-04-12 23:15:28 +00:00
jhb
13114caff8 Flip the switch and turn mpsafevm on by default for sparc64.
Approved by:	alc
2005-04-04 20:59:02 +00:00
phk
ccef1b4a6d sysctl node vm.stats can not be static (for ia64 reasons). 2005-02-11 16:34:14 +00:00
phk
0e0e2e5d1c Make three SYSCTL_NODEs static 2005-02-10 12:18:36 +00:00
imp
f0bf889d0d /* -> /*- for license, minor formatting changes 2005-01-07 02:29:27 +00:00
alc
aafcafb659 Enable debug.mpsafevm by default on alpha. 2004-12-17 17:17:36 +00:00
peter
09964b7499 Put on my peril sensitive sunglasses and add a flags field to the internal
sysctl routines and state.  Add some code to use it for signalling the need
to downconvert a data structure to 32 bits on a 64 bit OS when requested by
a 32 bit app.

I tried to do this in a generic abi wrapper that intercepted the sysctl
oid's, or looked up the format string etc, but it was a real can of worms
that turned into a fragile mess before I even got it partially working.

With this, we can now run 'sysctl -a' on a 32 bit sysctl binary and have
it not abort.  Things like netstat, ps, etc have a long way to go.

This also fixes a bug in the kern.ps_strings and kern.usrstack hacks.
These do matter very much because they are used by libc_r and other things.
2004-10-11 22:04:16 +00:00
alc
8ec6e44b75 Enable debug.mpsafevm by default on amd64 and i386. This enables copy-on-
write and zero-fill faults to run without holding Giant.  It is still
possible to disable Giant-free operation by setting debug.mpsafevm to 0 in
loader.conf.
2004-09-04 05:51:54 +00:00
alc
336d354baa - Introduce and use a new tunable "debug.mpsafevm". At present, setting
"debug.mpsafevm" results in (almost) Giant-free execution of zero-fill
   page faults.  (Giant is held only briefly, just long enough to determine
   if there is a vnode backing the faulting address.)

   Also, condition the acquisition and release of Giant around calls to
   pmap_remove() on "debug.mpsafevm".

   The effect on performance is significant.  On my dual Opteron, I see a
   3.6% reduction in "buildworld" time.

 - Use atomic operations to update several counters in vm_fault().
2004-08-16 06:16:12 +00:00
imp
04c9462c02 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core
2004-04-06 20:15:37 +00:00
alc
fca40d687b Avoid lock-order reversal between the vm object list mutex and the vm
object mutex.
2004-01-02 19:38:25 +00:00
obrien
b0678d7a44 Use __FBSDID(). 2003-06-11 23:50:51 +00:00
alc
eac23cf75a Lock some manipulations of the vm object's flags. 2003-04-13 19:36:18 +00:00
dillon
187e654d9a Make 'sysctl vm.vmtotal' work properly using updated patch from Hiten.
(the patch in the PR was stale).

PR:             kern/5689
Submitted by:   Hiten Pandya <hiten@unixdaemons.com>
2003-01-11 07:29:47 +00:00
alc
ed9a027a4a Add vm map and vm object locking to vmtotal(). 2003-01-03 05:52:02 +00:00
alc
73597ffcc2 Lock the vm object when performing vm_object_clear_flag(). 2003-01-02 09:09:27 +00:00
alc
c5121aa082 Eliminate some dead code. (Any possible use for this code died with
vm/vm_page.c revision 1.220.)

Submitted by:	bde
2002-12-23 04:35:38 +00:00
dillon
2afef11c57 The UP -current was not properly counting the per-cpu VM stats in the
sysctl code.  This makes 'systat -vm 1's syscall count work again.

Submitted by:	Michal Mertl <mime@traveller.cz>
Note:		also slated for 5.0
2002-12-22 05:04:30 +00:00
jhb
8c9a393a04 Rename the mutex thread and process states to use a more generic 'LOCK'
name instead.  (e.g., SLOCK instead of SMTX, TD_ON_LOCK() instead of
TD_ON_MUTEX())  Eventually a turnstile abstraction will be added that
will be shared with mutexes and other types of locks.  SLOCK/TDI_LOCK will
be used internally by the turnstile code and will not be specific to
mutexes.  Making the change now ensures that turnstiles can be dropped
in at a later date without affecting the ABI of userland applications.
2002-10-02 20:31:47 +00:00
julian
5702a380a5 Completely redo thread states.
Reviewed by:	davidxu@freebsd.org
2002-09-11 08:13:56 +00:00
julian
aa2dc0a5d9 Part 1 of KSE-III
The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by:	Almost everyone who counts
	(at various times, peter, jhb, matt, alfred, mini, bernd,
	and a cast of thousands)

	NOTE: this is still Beta code, and contains lots of debugging stuff.
	expect slight instability in signals..
2002-06-29 17:26:22 +00:00
alc
80bca30405 Reintroduce locking on accesses to vm_object_list. 2002-04-20 07:23:22 +00:00
dillon
a74c71d7cd Embed a struct vmmeter in the per-cpu structure and add a macro,
PCPU_LAZY_INC() which increments elements in it for cases where we
can afford the occassional inaccuracy.  Use of per-cpu stats counters
avoids significant cache stalls in various critical paths that would
otherwise severely limit our cpu scaleability.

Adjust all sysctl's accessing cnt.* elements to now use a procedure
which aggregates the requested field for all cpus and for the global
vmmeter.

The global vmmeter is retained, since some stats counters, like v_free_min,
cannot be made per-cpu.  Also, this allows us to convert counters from
the global vmmeter to the per-cpu vmmeter in a piecemeal fashion, so
have at it!
2002-04-04 21:38:47 +00:00
julian
37369620df In a threaded world, differnt priorirites become properties of
different entities.  Make it so.

Reviewed by:	jhb@freebsd.org (john baldwin)
2002-02-11 20:37:54 +00:00
iedowse
03bd269b08 Move the code that computes the system load average from vm_meter.c
to kern_synch.c in preparation for adding some jitter to the
inter-sample time.

Note that the "vm.loadavg" sysctl still lives in vm_meter.c which
isn't the right place, but it is appropriate for the current (bad)
name of that sysctl.

Suggested by:	jhb (some time ago)
Reviewed by:	bde
2001-10-20 13:10:43 +00:00
iedowse
721b742b1e Remove the SSLEEP case from the load average computation. This has
been a no-op for as long as our CVS history goes back. Processes in
state SSLEEP could only be counted if p_slptime == 0, but immediately
before loadav() is called, schedcpu() has just incremented p_slptime
on all SSLEEP processes.
2001-10-04 22:33:31 +00:00
julian
5596676e6c KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
dillon
cbc4469f38 whitespace / register cleanup 2001-07-04 19:00:13 +00:00
dillon
e028603b7e With Alfred's permission, remove vm_mtx in favor of a fine-grained approach
(this commit is just the first stage).  Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.
2001-07-04 16:20:28 +00:00
tmm
9ce8a62347 Clean up the code exporting interrupt statistics via sysctl a bit:
- move the sysctl code to kern_intr.c
- do not use INTRCNT_COUNT, but rather eintrcnt - intrcnt to determine
  the length of the intrcnt array
- move the declarations of intrnames, eintrnames, intrcnt and eintrcnt
  from machine-dependent include files to sys/interrupt.h
- remove the hw.nintr sysctl, it is not needed.
- fix various style bugs

Requested by:	bde
Reviewed by:	bde (some time ago)
2001-06-01 13:23:28 +00:00