Commit Graph

109 Commits

Author SHA1 Message Date
Bruce Evans
05b2c96fd3 Detect interrupt storms better. The storm detection didn't work at all
with an ASUS A7N8X-E motherboard in APIC mode, since storming interrupts
don't repeat immediately.  Use DELAY(1) to wait a bit for them to repeat.
This affects all systems.  Only delay for the first
(10 * intr_storm_threshold) interrupts (per interrupt handler) so that
this is only a pessimization while warming up.  Throttle after calling
the sub-handlers instead of before so that the long delay given by
throttling can be used instead of the DELAY(1) to detect storms after
warming up.

Reduced the throttling period from 1/10 second to 1/hz seconds so that
throttling doesn't destroy performance so much.  Interrupts that are
detected as storming are effectively handled by polling at a frequency
of hz Hz.  On A7N8X-E's there is another hardware or configuration bug
that makes the throttled frequency closer to 2*hz Hz.
2004-06-05 18:27:28 +00:00
Bruce Evans
7b1fe905ef Fixed some style bugs in previous commit (mainly an insertion sort error
for declarations, and poorly worded messages).

Fixed some nearby style bugs (unsorted declarations).
2004-04-17 02:46:05 +00:00
John Baldwin
7870c3c61c - Enable (unmask) interrupt sources earlier in the ithread loop.
Specifically, we used to enable the source after locking sched_lock
  and just before we had already decided to do a context switch.
  This meant that an ithread could never process more than one interrupt
  per context switch.  Enabling earlier in the loop before sched_lock is
  acquired allows an ithread to handle multiple interrupts per context
  switch if interrupts fire very rapidly.  For the case of heavy interrupt
  load this can reduce the number of context switches (and thus overhead)
  as well as reduce interrupt latency.
- Now that we can handle multiple interrupts per context switch, add simple
  interrupt storm protection to threaded interrupts.  If X number of
  consecutive interrupts are triggered before the itherad voluntarily
  yields to another thread, then the interrupt thread will sleep with the
  associated interrupt source disabled (masked) for 1/10th of a second.
  The default value of X is 500, but it can be tweaked via the tunable/
  sysctl hw.intr_storm_threshold.  If an interrupt storm is detected, then
  a message is output to the kernel console on the first occurrence per
  interrupt thread.  Interrupt storm protection can be disabled completely
  by setting this value to 0.  There is no scientific reasoning for the
  1/10th of a second or 500 interrupts values, so they may require tweaking
  at some point in the future.

Tested by:	rwatson (an earlier version w/o the storm protection)
Tested by:	mux (reportedly made a machine with two PCI interrupts
		storming usable rather than hard locked)
Reviewed by:	imp
2004-04-16 20:25:40 +00:00
John Baldwin
6074439965 kthread_exit() no longer requires Giant, so don't force callers to acquire
Giant just to call kthread_exit().

Requested by:	many
2004-03-05 22:42:17 +00:00
Jeff Roberson
29bcc4514f - Add a flags parameter to mi_switch. The value of flags may be SW_VOL or
SW_INVOL.  Assert that one of these is set in mi_switch() and propery
   adjust the rusage statistics.  This is to simplify the large number of
   users of this interface which were previously all required to adjust the
   proper counter prior to calling mi_switch().  This also facilitates more
   switch and locking optimizations.
 - Change all callers of mi_switch() to pass the appropriate paramter and
   remove direct references to the process statistics.
2004-01-25 03:54:52 +00:00
Don Lewis
288e351b55 If a device attach routine fails during boot and calls bus_teardown_intr(),
ithread_remove_handler() may fail to remove the interrupt handler if
it decides to let the ithread do the removal.  The problem is that during
boot "cold" is set, which causes msleep() to return immediately.  This
will cause ithread_remove_handler() to fail to wait for the ithread
to do the removal from the handler TAILQ before freeing the handler
back to the heap.  Bad things will happen when some other user of the
TAILQ, such as ithread_add_handler() or the actual ithread attempts to use
the freed handler.  Fix the problem by forcing ithread_remove_handler()
to do the actual removal itself if the "cold" flag is set.

Reviewed by:	jhb
2004-01-13 22:55:46 +00:00
Mark Murray
4e3a7a14d9 Fix a major faux pas of mine. I was causing 2 very bad things to
happen in interrupt context; 1) sleep locks, and 2) malloc/free
calls.

1) is fixed by using spin locks instead.

2) is fixed by preallocating a FIFO (implemented with a STAILQ)
   and using elements from this FIFO instead. This turns out
   to be rather fast.

OK'ed by:	re (scottl)
Thanks to:	peter, jhb, rwatson, jake
Apologies to:	*
2003-11-20 15:35:48 +00:00
Mark Murray
3fed54aaaa Hackfix to patch around a kernel panic I introduced. Real fix to
follow. In the meanwhile, we are not harvesting interrupt entropy.

Approved by:	re (jhb)
2003-11-18 14:35:43 +00:00
Peter Wemm
90e3387e54 Expand the argument to the ithread enable/disable helper hooks from an
int to something big enough to hold a pointer.  amd64 needs this.
2003-11-17 06:08:10 +00:00
John Baldwin
8bc0846476 Don't require INTR_FAST handlers to be exclusive in the MI layer. Instead,
let the MD code choose whether or not to implement such a policy.  The new
i386 interrupt code allows multiple FAST handlers for a given source for
example.  However, the code does not allow FAST and non-FAST handlers to be
mixed.
2003-11-03 22:42:58 +00:00
John Baldwin
8b201c42c6 - Add a DDB command 'show intrcnt' to show the non-zero interrupt counts.
- Add a DDB function to dump the contents of an ithread and optionally
  details about each handler in that ithread.  This function can be used
  by MD code to implement DDB commands that display information about
  interrupt sources and their registered handlers.
2003-10-24 21:05:30 +00:00
Scott Long
79501b66a7 Make swi_vm be INTR_MPSAFE. On all platforms, it is only used to activate
busdma_swi().  Now that busdma_swi() uses driver-provided locking, this
should be safe.
2003-07-01 16:00:38 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
Poul-Henning Kamp
670966596b Remove unused variable(s).
Found by:       FlexeLint
2003-05-31 20:29:34 +00:00
Julian Elischer
b1ac98d8b2 Move the flag that indicates an idle thread from the KSE to the thread.
It was always referenced via the thread anyhow.

Reviewed by:	jhb (a LOOOOONG time ago)
2003-05-02 00:33:12 +00:00
John Baldwin
e674d80790 Add some locking in for a few proc and thread fields. 2003-04-17 22:25:35 +00:00
John Baldwin
8804bf6b03 Use local struct proc variables to reduce repeated td->td_proc dereferences
and improve readability.
2003-04-17 22:02:47 +00:00
John Baldwin
9520fc2bed Adjust a KTR trace to log thread state instead of proc state as that is
more relevant.
2003-04-17 22:01:01 +00:00
John Baldwin
9b4982bfed Add a WITNESS_WARN() call to verify that we hold no locks after running
a handler from an interrupt thread.
2003-03-04 21:01:42 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Julian Elischer
4a338afd7a Move a bunch of flags from the KSE to the thread.
I was in two minds as to where to put them in the first case..
I should have listenned to the other mind.

Submitted by:	 parts by davidxu@
Reviewed by:	jeff@ mini@
2003-02-17 09:55:10 +00:00
Alfred Perlstein
c11110eabe Fix crash dumps on ata and scsi.
To fix scsi, don't wait for ithreads if we're dumping, it makes the
debugger sad.

To fix ata, use what appears to be a polling method if we're dumping,
I stole this from tmm but added code to ensure that this change is
only in effect while dumping.

Tested by: des
2003-02-14 13:10:40 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Jake Burkholder
24fbeaf9c3 Don't put a newline in KTR traces. 2002-12-28 23:22:22 +00:00
Robert Drehmel
bb8992b32c Instead of (sizeof(source_buffer) - 1) bytes, copy at most
(sizeof(destination_buffer) - 1) bytes into the destination buffer.
This was not harmful because they currently both provide space for
(MAXCOMLEN + 1) bytes.
2002-10-17 21:02:02 +00:00
Robert Drehmel
e80fb43467 Use strlcpy() instead of strncpy() to copy NUL terminated strings
for safety and consistency.
2002-10-17 20:03:38 +00:00
Scott Long
316ec49abd Some kernel threads try to do significant work, and the default KSTACK_PAGES
doesn't give them enough stack to do much before blowing away the pcb.
This adds MI and MD code to allow the allocation of an alternate kstack
who's size can be speficied when calling kthread_create.  Passing the
value 0 prevents the alternate kstack from being created.  Note that the
ia64 MD code is missing for now, and PowerPC was only partially written
due to the pmap.c being incomplete there.
Though this patch does not modify anything to make use of the alternate
kstack, acpi and usb are good candidates.

Reviewed by:	jake, peter, jhb
2002-10-02 07:44:29 +00:00
Poul-Henning Kamp
37c841831f Be consistent about "static" functions: if the function is marked
static in its prototype, mark it static at the definition too.

Inspired by:    FlexeLint warning #512
2002-09-28 17:15:38 +00:00
Jake Burkholder
98f93c07a5 Removed unneeded include (missed in last revision). 2002-09-22 06:05:23 +00:00
Jake Burkholder
e3b6e33c07 Moved netisr code from kern/kern_intr.c to net/netisr.c as threatened in a
comment.
2002-09-22 05:56:41 +00:00
Julian Elischer
71fad9fdee Completely redo thread states.
Reviewed by:	davidxu@freebsd.org
2002-09-11 08:13:56 +00:00
David Xu
65c17e749b Remove extra ';' 2002-09-06 00:18:52 +00:00
Julian Elischer
04774f2357 Slight cleanup of some comments/whitespace.
Make idle process state more consistant.
Add an assert on thread state.
Clean up idleproc/mi_switch() interaction.
Use a local instead of referencing curthread 7 times in a row
(I've been told curthread can be expensive on some architectures)
Remove some commented out code.
Add a little commented out code (completion coming soon)

Reviewed by:	jhb@freebsd.org
2002-08-01 18:45:10 +00:00
Julian Elischer
e602ba25fd 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
Julian Elischer
2d0231f5da diff reduction from KSE to keep WW-III from happenning on -current 2002-05-29 20:40:50 +00:00
John Baldwin
b106d2f56a - Set the base priority of an ithread that has no handlers when we set its
normal priority.
- Lock sched_lock while we dink with the priorities.
- Remove a few extra blank lines.
2002-04-11 21:03:35 +00:00
John Baldwin
2b60cfc5ce Don't lock the ithread lock in ithread_create(). The ithread isn't on any
lists or in any tables yet so there are no other references to it, thus
we don't need to lock it.
2002-04-09 16:26:37 +00:00
John Baldwin
6008862bc2 Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on:	i386, alpha, sparc64
2002-04-04 21:03:38 +00:00
Alfred Perlstein
4d77a549fe Remove __P. 2002-03-19 21:25:46 +00:00
Luigi Rizzo
2dbd9d5bc3 Make the DEVICE_POLLING code compile with -Werror and in LINT 2002-03-09 08:02:52 +00:00
Luigi Rizzo
daccb6386b MFS: synchronize the code with the version in -stable, specifically:
+ SYSCTL_ULONG -> SYSCTL_UINT
 + some procedure renaming and variable rearrangement
 + fix the 'interface going deaf' problem same as in -stable.
2002-02-11 23:56:18 +00:00
Julian Elischer
2c1007663f 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
Julian Elischer
079b7badea Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,
2002-02-07 20:58:47 +00:00
John Baldwin
c86b6ff551 Change the preemption code for software interrupt thread schedules and
mutex releases to not require flags for the cases when preemption is
not allowed:

The purpose of the MTX_NOSWITCH and SWI_NOSWITCH flags is to prevent
switching to a higher priority thread on mutex releease and swi schedule,
respectively when that switch is not safe.  Now that the critical section
API maintains a per-thread nesting count, the kernel can easily check
whether or not it should switch without relying on flags from the
programmer.  This fixes a few bugs in that all current callers of
swi_sched() used SWI_NOSWITCH, when in fact, only the ones called from
fast interrupt handlers and the swi_sched of softclock needed this flag.
Note that to ensure that swi_sched()'s in clock and fast interrupt
handlers do not switch, these handlers have to be explicitly wrapped
in critical_enter/exit pairs.  Presently, just wrapping the handlers is
sufficient, but in the future with the fully preemptive kernel, the
interrupt must be EOI'd before critical_exit() is called.  (critical_exit()
can switch due to a deferred preemption in a fully preemptive kernel.)

I've tested the changes to the interrupt code on i386 and alpha.  I have
not tested ia64, but the interrupt code is almost identical to the alpha
code, so I expect it will work fine.  PowerPC and ARM do not yet have
interrupt code in the tree so they shouldn't be broken.  Sparc64 is
broken, but that's been ok'd by jake and tmm who will be fixing the
interrupt code for sparc64 shortly.

Reviewed by:	peter
Tested on:	i386, alpha
2002-01-05 08:47:13 +00:00
Luigi Rizzo
e4fc250c15 Device Polling code for -current.
Non-SMP, i386-only, no polling in the idle loop at the moment.

To use this code you must compile a kernel with

        options DEVICE_POLLING

and at runtime enable polling with

        sysctl kern.polling.enable=1

The percentage of CPU reserved to userland can be set with

        sysctl kern.polling.user_frac=NN (default is 50)

while the remainder is used by polling device drivers and netisr's.
These are the only two variables that you should need to touch. There
are a few more parameters in kern.polling but the default values
are adequate for all purposes. See the code in kern_poll.c for
more details on them.

Polling in the idle loop will be implemented shortly by introducing
a kernel thread which does the job. Until then, the amount of CPU
dedicated to polling will never exceed (100-user_frac).
The equivalent (actually, better) code for -stable is at

	http://info.iet.unipi.it/~luigi/polling/

and also supports polling in the idle loop.

NOTE to Alpha developers:
There is really nothing in this code that is i386-specific.
If you move the 2 lines supporting the new option from
sys/conf/{files,options}.i386 to sys/conf/{files,options} I am
pretty sure that this should work on the Alpha as well, just that
I do not have a suitable test box to try it. If someone feels like
trying it, I would appreciate it.

NOTE to other developers:
sure some things could be done better, and as always I am open to
constructive criticism, which a few of you have already given and
I greatly appreciated.
However, before proposing radical architectural changes, please
take some time to possibly try out this code, or at the very least
read the comments in kern_poll.c, especially re. the reason why I
am using a soft netisr and cannot (I believe) replace it with a
simple timeout.

Quick description of files touched by this commit:

sys/conf/files.i386
        new file kern/kern_poll.c
sys/conf/options.i386
        new option
sys/i386/i386/trap.c
        poll in trap (disabled by default)
sys/kern/kern_clock.c
        initialization and hardclock hooks.
sys/kern/kern_intr.c
        minor swi_net changes
sys/kern/kern_poll.c
        the bulk of the code.
sys/net/if.h
        new flag
sys/net/if_var.h
        declaration for functions used in device drivers.
sys/net/netisr.h
        NETISR_POLL
sys/dev/fxp/if_fxp.c
sys/dev/fxp/if_fxpvar.h
sys/pci/if_dc.c
sys/pci/if_dcreg.h
sys/pci/if_sis.c
sys/pci/if_sisreg.h
        device driver modifications
2001-12-14 17:56:12 +00:00
David E. O'Brien
91f9161737 Repeat after me -- "Use of ANSI string concatenation can be bad."
In this case, C99's __func__ is properly defined as:

	static const char __func__[] = "function-name";

and GCC 3.1 will not allow it to be used in bogus string concatenation.
2001-12-10 05:40:12 +00:00
Julian Elischer
b40ce4165d 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
David E. O'Brien
6533ba2e33 Match the declaration in net/netisr.h.
Submitted by:	gcc 3.0.1
2001-09-03 03:24:31 +00:00
John Baldwin
688ebe120c - Close races with signals and other AST's being triggered while we are in
the process of exiting the kernel.  The ast() function now loops as long
  as the PS_ASTPENDING or PS_NEEDRESCHED flags are set.  It returns with
  preemption disabled so that any further AST's that arrive via an
  interrupt will be delayed until the low-level MD code returns to user
  mode.
- Use u_int's to store the tick counts for profiling purposes so that we
  do not need sched_lock just to read p_sticks.  This also closes a
  problem where the call to addupc_task() could screw up the arithmetic
  due to non-atomic reads of p_sticks.
- Axe need_proftick(), aston(), astoff(), astpending(), need_resched(),
  clear_resched(), and resched_wanted() in favor of direct bit operations
  on p_sflag.
- Fix up locking with sched_lock some.  In addupc_intr(), use sched_lock
  to ensure pr_addr and pr_ticks are updated atomically with setting
  PS_OWEUPC.  In ast() we clear pr_ticks atomically with clearing
  PS_OWEUPC.  We also do not grab the lock just to test a flag.
- Simplify the handling of Giant in ast() slightly.

Reviewed by:	bde (mostly)
2001-08-10 22:53:32 +00:00
John Baldwin
a300519d41 Make the schedlock saved critical section state a per-thread property. 2001-06-30 03:11:26 +00:00