set to SIGCHLD. This avoids the creation of orphaned Linux-threaded
zombies that init is unable to reap. This can occur when the parent
process sets its SIGCHLD to SIG_IGN. Fix a similar situation in the
PT_DETACH code.
Tested by: "Steven Hartland" <killing AT multiplay.co.uk>
mindful of blocking on disk I/O and instead return EBUSY when such
blocking would occur.
Results from the DeBox project indicate that blocking on disk I/O
can slow the performance of a kqueue/poll based webserver. Using
a flag such as SF_NODISKIO and throwing connections that would block
to helper processes/threads helped increase performance.
Currently, only the Flash webserver uses this flag, although it could
probably be applied to thttpd with relative ease.
Idea by: Yaoping Ruan & Vivek Pai
RLIM_INFINITY case for ogetrlimit().
- Use %jd and intmax_t to output negative time in usec in calcru().
- Rework getrusage() to make a copy of the rusage struct into a local
variable while holding Giant and then do the copyout from the local
variable to avoid having to have the original process rusage struct
locked while doing the copyout (which would not be safe). This also
includes a few style fixes from Bruce to getrusage().
Submitted by: bde (1, parts of 3)
Suggested by: bde (2)
failed, the reference count for the virtual memory object referenced
by the specified shared memory segment would have been erroneously
incremented.
Reported by: Joost Pol <joost@pine.nl>
- struct plimit includes a mutex to protect a reference count. The plimit
structure is treated similarly to struct ucred in that is is always copy
on write, so having a reference to a structure is sufficient to read from
it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
limits from a process to keep the limit structure from changing out from
under you while reading from it.
- Various global limits that are ints are not protected by a lock since
int writes are atomic on all the archs we support and thus a lock
wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
either an rlimit, or the current or max individual limit of the specified
resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
(it didn't used the stackgap when it should have) but uses lim_rlimit()
and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits. It
also no longer uses the stackgap for accessing sysctl's for the
ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result,
ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.
Submitted by: mtm (mostly, I only did a few cleanups and catchups)
Tested on: i386
Compiled on: alpha, amd64
- Rename temporary variable names ("tmp", "tmp2") to more informative
names ("load", "pctcpu", "rss", ...)
- Unclutter indentation and return paths: rather than lots of nested
ifs, simply return earlier if it's not going to work out. Simplify
general structure and avoid "deep" code.
- Comment on the thread/process selection and locking.
- Correct handling of "running"/"runnable" states, avoid "unknown"
that people were seeing for running processes. This was due to
a misunderstanding of the more complex state machine / inhibitors
behavior of KSE.
- Do perform ttyinfo() printing on KSE (P_SA) processes, it seems
generally to work.
While I initially attempted to formulate this as two commits (one
layout, the other content), I concluded that the layout changes were
really structural changes.
Many elements submitted by: bde
instead, just dec/inc in the ctor/dtor. For now, increment/decrement
in two's, since we're now performing the operation once per pair,
not once per pipe. Not really any measurable performance change
in my micro-benchmarks, but doing less work is good, especially when
it comes to atomic operations.
Suggested by: alc
changes to jointly allocated pipe pairs. Replace these checks
with pipe_present checks. This avoids a NULL pointer dereference
when a pipe is half-closed.
Submitted by: Peter Edwards <peter.edwards@openet-telecom.com>
1. Root from inside a jail was able to unmount any file system
(except /).
2. Unprivileged root was able to unmount file systems mounted by
privileged root (execpt /).
3. User from inside a jail was able to mount file system when
sysctl vfs.usermount was set to 1.
4. User was able to mount file system when vfs.usermount was set to 1
(that's ok) and unmount it even if vfs.usermount was equal to 0
(that's not correct).
Possibility from point 1 was reported by: Dariusz Kowalski <darek@76.pl>
Only a part of this fix will be MFC'ed (if approved).
PR: kern/60149
Reviewed by: rwatson
Approved by: scottl (mentor)
MFC after: 3 days
packet along with data, instead of in their own packet. When serving files
of size (packetsize - headersize) or smaller, this will result in one less
packet crossing the network. Quick testing with thttpd and http_load has
shown a noticeable performance improvement in this case (350 vs 330 fetches
per second.)
Included in this commit are two support routines, iov_to_uio, and m_uiotombuf;
these routines are used by sendfile to construct the header mbuf chain that
will be linked to the rest of the data in the socket buffer.
sense with sched_4bsd as it does with sched_ule.
- Use P_NOLOAD instead of the absence of td->td_ithd to determine whether or
not a thread should be accounted for in sched_tdcnt.
would allocate two 'struct pipe's from the pipe zone, and malloc a
mutex.
- Create a new "struct pipepair" object holding the two 'struct
pipe' instances, struct mutex, and struct label reference. Pipe
structures now have a back-pointer to the pipe pair, and a
'pipe_present' flag to indicate whether the half has been
closed.
- Perform mutex init/destroy in zone init/destroy, avoiding
reallocating the mutex for each pipe. Perform most pipe structure
setup in zone constructor.
- VM memory mappings for pageable buffers are still done outside of
the UMA zone.
- Change MAC API to speak 'struct pipepair' instead of 'struct pipe',
update many policies. MAC labels are also handled outside of the
UMA zone for now. Label-only policy modules don't have to be
recompiled, but if a module is recompiled, its pipe entry points
will need to be updated. If a module actually reached into the
pipe structures (unlikely), that would also need to be modified.
These changes substantially simplify failure handling in the pipe
code as there are many fewer possible failure modes.
On half-close, pipes no longer free the 'struct pipe' for the closed
half until a full-close takes place. However, VM mapped buffers
are still released on half-close.
Some code refactoring is now possible to clean up some of the back
references, etc; this patch attempts not to change the structure
of most of the pipe implementation, only allocation/free code
paths, so as to avoid introducing bugs (hopefully).
This cuts about 8%-9% off the cost of sequential pipe allocation
and free in system call tests on UP and SMP in my micro-benchmarks.
May or may not make a difference in macro-benchmarks, but doing
less work is good.
Reviewed by: juli, tjr
Testing help: dwhite, fenestro, scottl, et al
track the load for the sched_load() function. In the SMP case this member
is not defined because it would be redundant with the ksg_load member
which already tracks the non ithd load.
- For sched_load() in the UP case simply return ksq_sysload. In the SMP
case traverse the list of kseq groups and sum up their ksg_load fields.
of sched_load(). This variable tracks the number of running and runnable
non ithd threads. This removes the need to traverse the proc table and
discover how many threads are runnable.
at packet arrival.
For benchmarking purposes SO_BINTIME is preferable to SO_TIMEVAL
since it has higher resolution and lower overhead. Simultaneous
use of the two options is possible and they will return consistent
timestamps.
This introduces an extra test and a function call for SO_TIMEVAL, but I have
not been able to measure that.
profiling buffers and hash table. This makes it a lot easier to
do multiple profiling runs without rebooting or performing
gratuitous arithmetic. Sysctl is named debug.mutex.prof.reset.
Reviewed by: jake
- witness_lock() is split into two pieces: witness_checkorder() and
witness_lock(). Witness_checkorder() determines if acquiring a specified
lock at the time it is called would result in a lock order. It
optionally adds a new lock order relationship as well. witness_lock()
updates witness's data structures to assume that a lock has been acquired
by stick a new lock instance in the appropriate lock instance list.
- The mutex and sx lock functions now call checkorder() prior to trying to
acquire a lock and continue to call witness_lock() after the acquire is
completed. This will let witness catch a deadlock before it happens
rather than trying to do so after the threads have deadlocked (i.e. never
actually report it).
- A new function witness_defineorder() has been added that adds a lock
order between two locks at runtime without having to acquire the locks.
If the lock order cannot be added it will return an error. This function
is available to programmers via the WITNESS_DEFINEORDER() macro which
accepts either two mutexes or two sx locks as its arguments.
- A few simple wrapper macros were added to allow developers to call
witness_checkorder() anywhere as a way of enforcing locking assertions
in code that might acquire a certain lock in some situations. The
macros are: witness_check_{mutex,shared_sx,exclusive_sx} and take an
appropriate lock as the sole argument.
- The code to remove a lock instance from a lock list in witness_unlock()
was unnested by using a goto to vastly improve the readability of this
function.
assure backward compatibility (conditional on !BURN_BRIDGES), look it up
by its old name first, and log a warning (but accept the setting) if it
was found. If both the old and new name are defined, the new name takes
precedence.
Also export vm.kmem_size as a read-only sysctl variable; I find it hard to
tune a parameter when I don't know its default value, especially when that
default value is computed at boot time.
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.
mutex profiling code. As with existing mutex profiling, measurement
is done with respect to mtx_lock() instances in the code, as opposed
to specific mutexes. In particular, measure two things:
(1) Lock contention. How often did this mtx_lock() call get made and
have to sleep (or almost sleep) waiting for the lock. This helps
identify the "victims" of contention.
(2) Hold contention. How often, while the lock was held by a thread
as a result of this mtx_lock(), did another thread try to acquire
the same mutex. This helps identify the causes of contention.
I'm currently exploring adding measurement of "time waited for the
lock", but the current implementation has proven useful to me so far
so I figured I'd commit it so others could try it out. Note that this
increases the size of mutexes when MUTEX_PROFILING is enabled, so you
might find you need to further bump UMA_BOOT_PAGES. Fixes welcome.
The once over: des, others
one which runs the actual update. This fixes a bug where there were
a delay in applying the frequency adjustment. In extreme cases this
could result in marginal stability of the kernel-pll.
The uidinfo code appears to be MPSAFE, and is referenced without Giant
elsewhere. While this grab of Giant was only made in fairly rare
circumstances (actually GC'ing on refcount==0), grabbing Giant here
potentially introduces lock order issues with any locks held by the
caller. So this probably won't help performance much unless you change
credentials a lot in an application, and leave a lot of file descriptors
and cached credentials around. However, it simplifies locking down
consumers of the credential interfaces.
Bumped into by: sam
Appeased: tjr
to a new prison_complete() task run by a task queue. This removes
a requirement for grabbing Giant in crfree(). Embed the 'struct task'
in 'struct prison' so that we don't have to allocate memory from
prison_free() (which means we also defer the FREE()).
With this change, I believe grabbing Giant from crfree() can now be
removed, but need to check the uidinfo code paths.
To avoid header pollution, move the definition of 'struct task'
to _task.h, and recursively include from taskqueue.h and jail.h; much
preferably to all files including jail.h picking up a requirement to
include taskqueue.h.
Bumped into by: sam
Reviewed by: bde, tjr
In case no real/physical IEEE 802 address is available, both the expired
"draft-leach-uuids-guids-01" (section "4. Node IDs when no IEEE 802
network card is available") and RFC 2518 (section "6.4.1 Node Field
Generation Without the IEEE 802 Address") recommend (quoted from RFC
2518):
"The ideal solution is to obtain a 47 bit cryptographic quality random
number, and use it as the low 47 bits of the node ID, with the _most_
significant bit of the first octet of the node ID set to 1. This bit
is the unicast/multicast bit, which will never be set in IEEE 802
addresses obtained from network cards; hence, there can never be a
conflict between UUIDs generated by machines with and without network
cards."
Unfortunately, this incorrectly explains how to implement this and
the FreeBSD UUID generator code inherited this generation bug from
the broken reference code in the standards draft. They should instead
specify the "_least_ significant bit of the first octet of the node ID"
as the multicast bit in a memory and hexadecimal string representation
of a 48-bit IEEE 802 MAC address.
This standards bug arised from a false interpretation, as the multicast
bit is actually the _most_ significant bit in IEEE 802.3 (Ethernet)
_transmission order_ of an IEEE 802 MAC address. The standards authors
forgot that the bitwise order of an _octet_ from a MAC address _memory_
and hexadecimal string representation is still always from left (MSB,
bit 7) to right (LSB, bit 0).
Fortunately, this UUID generation bug could have occurred on systems
without any Ethernet NICs only.
Presumably, at some point, you had to include jail.h if you included
proc.h, but that is no longer required.
Result of: self injury involving adding something to struct prison
in OpenBSD by Niels Provos. The patch introduces a bitmap of allocated
file descriptors which is used to locate available descriptors when a new
one is needed. It also moves the task of growing the file descriptor table
out of fdalloc(), reducing complexity in both fdalloc() and do_dup().
Debts of gratitude are owed to tjr@ (who provided the original patch on
which this work is based), grog@ (for the gdb(4) man page) and rwatson@
(for assistance with pxeboot(8)).
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
a maximum dump size of 0, return a size-related error, rather
than returning success. Otherwise, waitpid() will incorrectly
return a status indicating that a core dump was created. Note
that the specific error doesn't actually matter, since it's lost.
MFC after: 2 weeks
PR: 60367
Submitted by: Valentin Nechayev <netch@netch.kiev.ua>
avoid relying on the minimum memory allocation size to avoid problems.
The check is somewhat redundant because the consumers of the returned
structure will check that sa_len is a protocol-specific larger size.
Submitted by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: nectar
MFC after: 30 days
setting the new process' p_pgrp again before inserting it in the p_pglist.
Without it we can get the new process to be inserted in a different p_pglist
than the one p2->p_pgrp points to, and this is not something we want to happen.
This is not a fix, merely a bandaid, but it will work until someone finds a
better way to do it.
Discussed with: jhb (a long time ago)
in slightly less usual states:
If the thread is on a run queue, display "running" if the thread is
actually running, otherwise, "runnable".
If the thread is sleeping, and it's on a sleep queue, display the
name of the queue, otherwise "unknown" -- previously, in this situation
we would display "iowait".
If the thread is waiting on a lock, display *lockname.
If the thread is suspended, display "suspended" -- previously, in
this situation we would display "iowait".
If the thread is waiting for an interrupt, display "intrwait" --
previously, in this situation we would display "iowait".
If the thread is in a state not handled by the above, display
"unknown" -- previously, we would print "iowait".
Among other things, this avoids displaying "iowait" when the foreground
process turns out to be suspended waiting for a debugger to properly
attach.
holding the mutex. Because the sigacts pointer can't change while
the process is "live" (proc locking (x)), we know our pointer is still
valid.
In communication with: truckman
Reviewed by: jhb
on a non-recursive mutex will fail but will not trigger any assertions.
- Add an assertion to mtx_lock() that one never recurses on a non-recursive
mutex. This is mostly useful for the non-WITNESS case.
Requested by: deischen, julian, others (1)
Add empty line before first code line in functions with no local
variables.
Properly terminate comment sentences.
Indent lines which are longer that 80 characters.
Move v_addpollinfo closer to the rest of poll-related functions.
Move DEBUG_VFS_LOCKS ifdefed block to the end of file.
Obtained from: bde (partly)
is useless for threaded programs, multiple threads can not share same
stack.
The alternative signal stack is private for thread, no lock is needed,
the orignal P_ALTSTACK is now moved into td_pflags and renamed to
TDP_ALTSTACK.
For single thread or Linux clone() based threaded program, there is no
semantic changed, because those programs only have one kernel thread
in every process.
Reviewed by: deischen, dfr
o promote several m_tag_* routines to inline
o add an m_tag_setup inline to set the fixed fields in a packet tag
o add an m_tag_free method pointer to each mtag to support, for example,
allocating tags from zones
o have m_tag_find check if the tag list is not empty before calling
m_tag_locate to search
Reviewed by: brooks, silence from others
with one of std{in,out,err} open. This helps with the file descriptor
leaks reported on -current. This should probably be merged into 5.2.
Reviewed by: ru
Tested by: Bjoern A. Zeeb <bzeeb-lists@lists.zabbadoz.net>
function back to near the beginning of the file. Rev.1.194 moved it into
the middle of auxiliary functions following kern_execve(). Moved the
__mac_execve() syscall function up together with execve(). It was new in
rev1.1.196 and perfectly misplaced after execve().
sched_cpu() locks an sx lock (allproc_lock) which can sleep if it fails to
acquire the lock, it is not safe to execute this in a callout handler from
softclock().
use it, if we ever did. They have been been VERY poorly maintained for
some time, possibly because they were a NOP. FWIW, This brings our table
formats back closer to the other *BSD's.
cpu could have been bogged down with non-transferable load and still not
migrated a new thread to an idle cpu. This required some benchmarking and
tuning to get right as the comment above it suggests.
- In sched_add(), do the idle check prior to the transfer check so that we
don't try to transfer load from an idle cpu. This fixes panics caused by
IPIs on UP machines running SMP kernels.
Reported/Debugged by: seanc
reassigning their v_ops field to specfs, detaching from the mountpoint, etc.
However, this is not sufficient. If we vclean() the vnode the pages owned
by the vnode are lost, potentially while buffers reference them. Implement
parts of vclean() seperately in vgonechrl() so that the pages and bufs
associated with a device vnode are not destroyed while in use.
- The new sched_balance_groups() function does intra-group balancing while
sched_balance() balances the available groups.
- Pick a random time between 0 ticks and hz * 2 ticks to restart each
balancing process. Each balancer has its own timeout.
- Pick a random place in the list of groups to start the search for lowest
and highest group loads. This prevents us from prefering a group based on
numeric position.
- Use a nasty hack to stop us from preferring cpu 0. The problem is that
softclock always runs on cpu 0, so it always has a little extra load. We
ignore this load in the balancer for now. In the future softclock should
run on a random cpu and these hacks can go away.
cpu are added to a group.
- Don't place a cpu into the kseq_idle bitmask until all cpus in that group
have idled.
- Prefer idle groups over idle group members in the new kseq_transfer()
function. In this way we will prefer to balance load across full cores
rather than add further load a partial core.
- Before a cpu goes idle, check the other group members for threads. Since
SMT cpus may freely share threads, this is cheap.
- SMT cores may be individually pinned and bound to now. This contrasts the
old mechanism where binding or pinning would have allowed a thread to run
on any available cpu.
- Remove some unnecessary logic from sched_switch(). Priority propagation
should be properly taken care of in sched_prio() now.
turnstile_unpend(). A racing thread that does not have TDI_LOCK set may
either be running on another CPU or it may be sitting on a run queue if it
was preempted during the very small window in turnstile_wait() between
unlocking the turnstile chain lock and locking sched_lock.
case of a turnstile having no threads is just one instance of the more
general case where the thread we are examining has been partially awakened
already in that it has been removed from the turnstile's blocked list but
still has TDI_LOCK set. We detect that case by checking to see if the
thread has already had a turnstile reassigned to it.
functions less noisy: We printf if a new function took longer than
the previous record holder, or of the previous record holder took
more than twice as long as the current record.
to have the kernel switch to a new thread, instead of doing it in
userland. It is in fact needed on ia64 where syscall restarts do not
return to userland first. It's completely handled inside the kernel.
As such, any context created by the kernel as part of an upcall and
caused by some syscall needs to be restored by the kernel.
Be sure to shift (long)1 << 33 and higher, not (int)1. Otherwise bad
things happen(TM). This is why beast.freebsd.org paniced with ULE.
Reviewed by: jeff
and the mpo_create_cred() MAC policy entry point to
mpo_copy_cred_label(). This is more consistent with similar entry
points for creation and label copying, as mac_create_cred() was
called from crdup() as opposed to during process creation. For
a number of policies, this removes the requirement for special
handling when copying credential labels, and improves consistency.
Approved by: re (scottl)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
1) mp_maxid is a valid FreeBSD CPU ID in the range 0 .. MAXCPU - 1.
2) For all active CPUs in the system, PCPU_GET(cpuid) <= mp_maxid.
Approved by: re (scottl)
Tested on: i386, amd64, alpha
aid other kernel code, especially code which can be in a module such as
the acpi_cpu(4) driver, to work properly with both SMP and UP kernels.
The exported symbols include mp_ncpus, all_cpus, mp_maxid, smp_started, and
the smp_rendezvous() function. This also means that CPU_ABSENT() is now
always implemented the same on all kernels.
Approved by: re (scottl)
to sendfile(2) being erroneously automatically restarted after a signal
is delivered. Fixed by converting ERESTART to EINTR prior to exiting.
Updated manual page to indicate the potential EINTR error, its cause
and consequences.
Approved by: re@freebsd.org
forced unmount case. Otherwise, a file system that is referenced
only by process fd_cdir/fd_rdir references to the file system root
vnode will be successfully unmounted without the MNT_FORCE flag.
The previous behaviour was not compatible with the unmount semantics
required by amd(8), so file systems could be unexpectedly unmounted
while there were still references to the file system root directory.
Reported by: Erez Zadok <ezk@cs.sunysb.edu>
Approved by: re (scottl)
very early (SI_SUB_TUNABLES - 1) and is responsible for setting mp_maxid.
cpu_mp_probe() is now called at SI_SUB_CPU and determines if SMP is
actually present and sets mp_ncpus and all_cpus. Splitting these up
allows an architecture to probe CPUs later than SI_SUB_TUNABLES by just
setting mp_maxid to MAXCPU in cpu_mp_setmaxid(). This could allow the
CPU probing code to live in a module, for example, since modules
sysinit's in modules cannot be invoked prior to SI_SUB_KLD. This is
needed to re-enable the ACPI module on i386.
- For the alpha SMP probing code, use LOCATE_PCS() instead of duplicating
its contents in a few places. Also, add a smp_cpu_enabled() function
to avoid duplicating some code. There is room for further code
reduction later since much of this code is also present in cpu_mp_start().
- All archs besides i386 still set mp_maxid to the same values they set it
to before this change. i386 now sets mp_maxid to MAXCPU.
Tested on: alpha, amd64, i386, ia64, sparc64
Approved by: re (scottl)
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: *
the MAC label referenced from 'struct socket' in the IPv4 and
IPv6-based protocols. This permits MAC labels to be checked during
network delivery operations without dereferencing inp->inp_socket
to get to so->so_label, which will eventually avoid our having to
grab the socket lock during delivery at the network layer.
This change introduces 'struct inpcb' as a labeled object to the
MAC Framework, along with the normal circus of entry points:
initialization, creation from socket, destruction, as well as a
delivery access control check.
For most policies, the inpcb label will simply be a cache of the
socket label, so a new protocol switch method is introduced,
pr_sosetlabel() to notify protocols that the socket layer label
has been updated so that the cache can be updated while holding
appropriate locks. Most protocols implement this using
pru_sosetlabel_null(), but IPv4/IPv6 protocols using inpcbs use
the the worker function in_pcbsosetlabel(), which calls into the
MAC Framework to perform a cache update.
Biba, LOMAC, and MLS implement these entry points, as do the stub
policy, and test policy.
Reviewed by: sam, bms
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
to see_other_uids but with the logical conversion. This is based
on (but not identical to) the patch submitted by Samy Al Bahra.
Submitted by: Samy Al Bahra <samy@kerneled.com>
- This is heavily derived from John Baldwin's apic/pci cleanup on i386.
- I have completely rewritten or drastically cleaned up some other parts.
(in particular, bootstrap)
- This is still a WIP. It seems that there are some highly bogus bioses
on nVidia nForce3-150 boards. I can't stress how broken these boards
are. I have a workaround in mind, but right now the Asus SK8N is broken.
The Gigabyte K8NPro (nVidia based) is also mind-numbingly hosed.
- Most of my testing has been with SCHED_ULE. SCHED_4BSD works.
- the apic and acpi components are 'standard'.
- If you have an nVidia nForce3-150 board, you are stuck with 'device
atpic' in addition, because they somehow managed to forget to connect the
8254 timer to the apic, even though its in the same silicon! ARGH!
This directly violates the ACPI spec.
system calls, and prefer these calls over getsockopt()/setsockopt()
for ABI reasons. When addressing UNIX domain sockets, these calls
retrieve and modify the socket label, not the label of the
rendezvous vnode.
- Create mac_copy_socket_label() entry point based on
mac_copy_pipe_label() entry point, intended to copy the socket
label into temporary storage that doesn't require a socket lock
to be held (currently Giant).
- Implement mac_copy_socket_label() for various policies.
- Expose socket label allocation, free, internalize, externalize
entry points as non-static from mac_net.c.
- Use mac_socket_label_set() in __mac_set_fd().
MAC-aware applications may now use mac_get_fd(), mac_set_fd(), and
mac_get_peer() to retrieve and set various socket labels without
directly invoking the getsockopt() interface.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
physical mapping.
- Move the sf_buf API to its own header file; make struct sf_buf's
definition machine dependent. In this commit, we remove an
unnecessary field from struct sf_buf on the alpha, amd64, and ia64.
Ultimately, we may eliminate struct sf_buf on those architecures
except as an opaque pointer that references a vm page.
sure to sooptcopyin() the (struct mac) so that the MAC Framework
knows which label types are being requested. This fixes process
queries of socket labels.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
kses from the run queues. Also, on SMP, we track the transferable
count here. Threads are transferable only as long as they are on the
run queue.
- Previously, we adjusted our load balancing based on the transferable count
minus the number of actual cpus. This was done to account for the threads
which were likely to be running. All of this logic is simpler now that
transferable accounts for only those threads which can actually be taken.
Updated various places in sched_add() and kseq_balance() to account for
this.
- Rename kseq_{add,rem} to kseq_load_{add,rem} to reflect what they're
really doing. The load is accounted for seperately from the runq because
the load is accounted for even as the thread is running.
- Fix a bug in sched_class() where we weren't properly using the PRI_BASE()
version of the kg_pri_class.
- Add a large comment that describes the impact of a seemingly simple
conditional in sched_add().
- Also in sched_add() check the transferable count and KSE_CAN_MIGRATE()
prior to checking kseq_idle. This reduces the frequency of access for
kseq_idle which is a shared resource.
in exit1(), make sure the p_klist is empty after sending NOTE_EXIT.
The process won't report fork() or execve() and won't be able to handle
NOTE_SIGNAL knotes anyway.
This fixes some race conditions with do_tdsignal() calling knote() while
the process is exiting.
Reported by: Stefan Farfeleder <stefan@fafoe.narf.at>
MFC after: 1 week
parts of ptrace using proc_rwmem(). proc_rwmem() requires giant, and
giant must be acquired prior to the proc lock, so ptrace must require giant
still.
Give the HZ/overflow check a 10% margin.
Eliminate bogus newline.
If timecounters have equal quality, prefer higher frequency.
Some inspiration from: bde
and empty its turnstile while the blocking threads still pointed to the
turnstile. If the thread on the first CPU blocked on a lock owned by
one of the threads blocked on the turnstile just woken up, then the
first CPU could try to manipulate a bogus thread queue in the turnstile
during priority propagation.
- Update locking notes for ts_owner and always clear ts_owner, not just
under INVARIANTS.
Tested by: sam (1)
deleted in 1.81. Increase the initial timeout limit to 2ms to
eliminate spurious messages of excessive timeouts in the NFS
client code.
Requested by: Poul-Henning Kamp <phk@phk.freebsd.dk>
Requested by: Mike Silbersack <silby@silby.com>
Requested by: Sam Leffler <sam@errno.com>
Giant and is also MPSAFE.
Push Giant further down into __mac_get_fd() and __mac_set_fd(),
grabbing it only for constrained regions dealing with VFS, and
dropping it entirely for operations related to labeling of pipes.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
after the additions made for the new statfs structure (version
1.157). These must be updated in a separate checkin after
syscalls.master has been checked in so that they reflect its
new CVS identity. As these are purely derived files, it is not
clear to me why they are under CVS at all. I presume that it has
something to do with having `make world' operate properly.
accurate reporting of multi-terabyte filesystem sizes.
You should build and boot a new kernel BEFORE doing a `make world'
as the new kernel will know about binaries using the old statfs
structure, but an old kernel will not know about the new system
calls that support the new statfs structure. Running an old kernel
after a `make world' will cause programs such as `df' that do a
statfs system call to fail with a bad system call.
Reviewed by: Bruce Evans <bde@zeta.org.au>
Reviewed by: Tim Robbins <tjr@freebsd.org>
Reviewed by: Julian Elischer <julian@elischer.org>
Reviewed by: the hoards of <arch@freebsd.org>
Sponsored by: DARPA & NAI Labs.
in various kernel objects to represent security data, we embed a
(struct label *) pointer, which now references labels allocated using
a UMA zone (mac_label.c). This allows the size and shape of struct
label to be varied without changing the size and shape of these kernel
objects, which become part of the frozen ABI with 5-STABLE. This opens
the door for boot-time selection of the number of label slots, and hence
changes to the bound on the number of simultaneous labeled policies
at boot-time instead of compile-time. This also makes it easier to
embed label references in new objects as required for locking/caching
with fine-grained network stack locking, such as inpcb structures.
This change also moves us further in the direction of hiding the
structure of kernel objects from MAC policy modules, not to mention
dramatically reducing the number of '&' symbols appearing in both the
MAC Framework and MAC policy modules, and improving readability.
While this results in minimal performance change with MAC enabled, it
will observably shrink the size of a number of critical kernel data
structures for the !MAC case, and should have a small (but measurable)
performance benefit (i.e., struct vnode, struct socket) do to memory
conservation and reduced cost of zeroing memory.
NOTE: Users of MAC must recompile their kernel and all MAC modules as a
result of this change. Because this is an API change, third party
MAC modules will also need to be updated to make less use of the '&'
symbol.
Suggestions from: bmilekic
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
vfs_mount_alloc/vfs_mount_destroy functions and take care to completely
destroy the mount point along with its locks. Mount struct has grown in
coplexity recently and depending on each failure path to destroy it
completely isn't working anymore.
2. Eliminate largely identical vfs_mount and vfs_unmount question by
moving the code to handle both cases into a newly introduced vfs_domount
function.
3. Simplify nfs_mount_diskless to always expect an allocated mount
struct and never attempt an allocation/destruction itself. The
vfs_allocroot allocation was there to support 'magic' swap space
configuration for diskless clients that was already removed by PHK some
time ago.
4. Include a vfs_buildopts cleanups by Peter Edwards to validate the
sanity of nmount parameters passed from userland.
Submitted by: (4) Peter Edwards <peter.edwards@openet-telecom.com>
Reviewed by: rwatson
turnstiles to implement blocking isntead of implementing a thread queue
directly. These turnstiles are somewhat similar to those used in Solaris 7
as described in Solaris Internals but are also different.
Turnstiles do not come out of a fixed-sized pool. Rather, each thread is
assigned a turnstile when it is created that it frees when it is destroyed.
When a thread blocks on a lock, it donates its turnstile to that lock to
serve as queue of blocked threads. The queue associated with a given lock
is found by a lookup in a simple hash table. The turnstile itself is
protected by a lock associated with its entry in the hash table. This
means that sched_lock is no longer needed to contest on a mutex. Instead,
sched_lock is only used when manipulating run queues or thread priorities.
Turnstiles also implement priority propagation inherently.
Currently turnstiles only support mutexes. Eventually, however, turnstiles
may grow two queue's to support a non-sleepable reader/writer lock
implementation. For more details, see the comments in sys/turnstile.h and
kern/subr_turnstile.c.
The two primary advantages from the turnstile code include: 1) the size
of struct mutex shrinks by four pointers as it no longer stores the
thread queue linkages directly, and 2) less contention on sched_lock in
SMP systems including the ability for multiple CPUs to contend on different
locks simultaneously (not that this last detail is necessarily that much of
a big win). Note that 1) means that this commit is a kernel ABI breaker,
so don't mix old modules with a new kernel and vice versa.
Tested on: i386 SMP, sparc64 SMP, alpha SMP
ktr_resize_pool(); this eliminates a potential livelock.
Return ENOSPC only if we encountered an out-of-memory condition when
trying to increase the pool size.
Reviewed by: jhb, bde (style)
consistency initialized. Consequently, a number of conditionals that
checked the validity of b_object before passing it to VM_OBJECT_LOCK()
and VM_OBJECT_UNLOCK() are no longer needed.
because RFNOWAIT was being passed to kproc_create.
The result was that shutdown took quite a bit longer because this
errant "child" would not respond to termination signals from init
at system shutdown.
RFNOWAIT dissassociates itself from the caller by attaching to init
as a parent proc. We could have had the taskqueue proc listen for
SIGKILL, but being able to SIGKILL a potentially critical system
process doesn't seem like a good idea.
free one sem_undo with un_cnt == 0 instead of all of them. This is a
temporary workaround until the SLIST_FOREACH_PREVPTR loop gets fixed so
that it doesn't cause cycles in semu_list when removing multiple adjacent
items. It might be easier to just use (doubly-linked) LISTs here instead
of complicated SLIST code to achieve O(1) removals.
This bug manifested itself as a complete lockup under heavy semaphore use
by multiple processes with the SEM_UNDO flag set.
PR: 58984
Since all callers either passed 0 or 1 for clear_ret, define bit 0 in
the flags for use as clear_ret. Reserve bits 1, 2 and 3 for use by MI
code for possible (but unlikely) future use. The remaining bits are for
use by MD code.
This change is triggered by a need on ia64 to have another knob for
get_mcontext().
in the log message for kern_sched.c 1.83 (which should have been
repo-copied to preserve history for this file), the (4BSD) scheduler
algorithm only works right if stathz is nearly 128 Hz. The old
commit lock said 64 Hz; the scheduler actually wants nearly 16 Hz
but there was a scale factor of 4 to give the requirement of 64 Hz,
and rev.1.83 changed the scale factor so that the requirement became
128 Hz. The change of the scale factor was incomplete in the SMP
case. Then scheduling ticks are provided by smp_ncpu CPUs, and the
scheduler cannot tell the difference between this and 1 CPU providing
scheduling ticks smp_ncpu times faster, so we need another scale
factor of smp_ncp or an algorithm change.
This quick fix uses the scale factor without even trying to optimize
the runtime divisions required for this as is done for the other
scale factor.
The main algorithmic problem is the clamp on the scheduling tick counts.
This was 295; it is now approximately 295 * smp_ncpu. When the limit
is reached, threads get free timeslices and scheduling becomes very
unfair to the threads that don't hit the limit. The limit can be
reached and maintained in the worst case if the load average is larger
than (limit / effective_stathz - 1) / 2 = 0.65 now (was just 0.08 with
2 CPUs before this change), so there are algorithmic problems even for
a load average of 1. Fortunately, the worst case isn't common enough
for the problem to be very noticeable (it is mainly for niced CPU hogs
competing with less nice CPU hogs).
thread being waken up. The thread waken up can run at a priority as
high as after tsleep().
- Replace selwakeup()s with selwakeuppri()s and pass appropriate
priorities.
- Add cv_broadcastpri() which raises the priority of the broadcast
threads. Used by selwakeuppri() if collision occurs.
Not objected in: -arch, -current
whether or not the isr needs to hold Giant when running; Giant-less
operation is also controlled by the setting of debug_mpsafenet
o mark all netisr's except NETISR_IP as needing Giant
o add a GIANT_REQUIRED assertion to the top of netisr's that need Giant
o pickup Giant (when debug_mpsafenet is 1) inside ip_input before
calling up with a packet
o change netisr handling so swi_net runs w/o Giant; instead we grab
Giant before invoking handlers based on whether the handler needs Giant
o change netisr handling so that netisr's that are marked MPSAFE may
have multiple instances active at a time
o add netisr statistics for packets dropped because the isr is inactive
Supported by: FreeBSD Foundation
since there is no direct association between M:N thread and kse,
sometimes, a thread does not have a kse, in that case, return a pctcpu
from its last kse, it is not perfect, but gives a good number to be
displayed.
Instead, let the vm objects be lazily instantiated at fault time. This
results in the allocation of fewer vm objects and vm map entries due to
aggregation in the vm system.
o move it from subr_bus.c to netisr.c where it more properly belongs
o add NET_PICKUP_GIANT and NET_DROP_GIANT macros that will be used to
grab Giant as needed when MPSAFE operation is enabled
Supported by: FreeBSD Foundation
Introduce two new macros MNT_ILOCK(mp)/MNT_IUNLOCK(mp) to
operate on this mutex transparently.
Eventually new mutex will be protecting more fields in
struct mount, not only vnode list.
Discussed with: jeff
1.36 +73 -60 src/sys/compat/linux/linux_ipc.c
1.83 +102 -48 src/sys/kern/sysv_shm.c
1.8 +4 -0 src/sys/sys/syscallsubr.h
That change was intended to support vmware3, but
wantrem parameter is useless because vmware3 uses SYSV shared memory
to talk with X server and X server is native application.
The patch worked because check for wantrem was not valid
(wantrem and SHMSEG_REMOVED was never checked for SHMSEG_ALLOCATED segments).
Add kern.ipc.shm_allow_removed (integer, rw) sysctl (default 0) which when set
to 1 allows to return removed segments in
shm_find_segment_by_shmid() and shm_find_segment_by_shmidx().
MFC after: 1 week
waitrunningbufspace() calls so that they are always able to
proceed and clean up buffer space.
Submitted by: Brian Fundakowski Feldman <green@freebsd.org>
Use zpfind() to see if the process became a zombie if pfind() doesn't find it
and if the caller wants to know about process death, so that the caller knows
the process died even if it happened before the kevent was actually registered.
MFC after: 1 week
This fixes a race condition (specifically with signal events) that could
lead to the kn being re-inserted into the list after it has been destroyed,
which is not something we want to happen.
PR: kern/58258
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.
idle. They figure out that we're idle fast enough that the cache pollution
introduces by scanning their run queue is more expensive than waiting
a little longer.
- Add kseq_setidle() to mark us as being idle. Use this in place of
kseq_find().
- Remove kseq_load_highest(), kseq_find() was the only consumer of this
interface. kseq_balance() has it's own customized version that finds the
lowest and highest loads simultaneously.
Continuously told that this would be faster by: terry
the total load, the timeshare load, and the number of threads that can
be migrated to another cpu. Account for these seperately.
- Introduce a KSE_CAN_MIGRATE() macro which determines whether or not a KSE
can be migrated to another CPU. Currently, this only checks to see if
we're an interrupt handler. Eventually this will also be used to support
CPU binding.
wasn't curthread, i.e. when we receive a thread pointer to use
as a function argument. Use VOP_UNLOCK/vrele in these cases.
The only case there td != curthread known at the moment is
boot() calling sync with thread0 pointer.
This fixes the panic on shutdown people have reported.
slice assignment. Add a comment describing what it does.
- Remove a stale XXX comment, the nice should not impact the interactivity,
nice adjustments only effect non-interactive tasks in ULE.
- Don't allow nice -20 tasks to totally starve nice 0 tasks. Give them at
least SCHED_SLICE_MIN ticks. We still allow nice 0 tasks to starve nice
+20 tasks as intended.
- SCHED_PRI_NRESV does not have the off by one error in PRIO_TOTAL so we
do not have to account for it in the few places that we use it.
Requested by: bde
0 and SCHED_SLP_RUN_MAX * 2. This allows us to simplify the algorithm
quite a bit. Before, it dealt with arbitrary values which required us
to do nasty integer division tricks that didn't quite work out correctly.
- Chnage sched_wakeup() to detect conditions where the slp+runtime could
exceed SCHED_SLP_RUN_MAX * 2. This can happen if we go to sleep for
longer than 6 seconds. In this case, we'll just clear the runtime and
set the sleep time to the max.
- Define a new function, sched_interact_fork() which updates the slp+runtime
of a newly forked thread. We want to limit the amount of history retained
from the parent so that we learn the child's behavior quickly. We don't,
however want to decay it to nothing. Previously, we would simply divide
each parameter by 100 whenever we forked. After a few forks the values
would reach 0 and tasks would not be considered interactive.
- Add another KTR entry, cleanup some existing entries.
- Remove a useless sched_interact_update() from sched_priority(). This is
already done by the callers that require it.
- Add an IPI based mechanism for migrating kses. This mechanism is
broken down into several components. This is intended to reduce cache
thrashing by eliminating most cases where one cpu touches another's
run queues.
- kseq_notify() appends a kse to a lockless singly linked list and
conditionally sends an IPI to the target processor. Right now this is
protected by sched_lock but at some point I'd like to get rid of the
global lock. This is why I used something more complicated than a
standard queue.
- kseq_assign() processes our list of kses that have been assigned to us
by other processors. This simply calls sched_add() for each item on the
list after clearing the new KEF_ASSIGNED flag. This flag is used to
indicate that we have been appeneded to the assigned queue but not
added to the run queue yet.
- In sched_add(), instead of adding a KSE to another processor's queue we
use kse_notify() so that we don't touch their queue. Also in sched_add(),
if KEF_ASSIGNED is already set return immediately. This can happen if
a thread is removed and readded so that the priority is recorded properly.
- In sched_rem() return immediately if KEF_ASSIGNED is set. All callers
immediately readd simply to adjust priorites etc.
- In sched_choose(), if we're running an IDLE task or the per cpu idle thread
set our cpumask bit in 'kseq_idle' so that other processors may know that
we are idle. Before this, make a single pass through the run queues of
other processors so that we may find work more immediately if it is
available.
- In sched_runnable(), don't scan each processor's run queue, they will IPI
us if they have work for us to do.
- In sched_add(), if we're adding a thread that can be migrated and we have
plenty of work to do, try to migrate the thread to an idle kseq.
- Simplify the logic in sched_prio() and take the KEF_ASSIGNED flag into
consideration.
- No longer use kseq_choose() to steal threads, it can lose it's last
argument.
- Create a new function runq_steal() which operates like runq_choose() but
skips threads based on some criteria. Currently it will not steal
PRI_ITHD threads. In the future this will be used for CPU binding.
- Create a kseq_steal() that checks each run queue with runq_steal(), use
kseq_steal() in the places where we used kseq_choose() to steal with
before.
clobbers this variable. Long ago, when the idle loop wasn't in a
process, it set switchtime.tv_sec to zero to indicate that the time
needs to be read after the idle loop finishes. The special case for
this isn't needed now that there is an idle process (for each CPU).
The time is read in the normal way when the idle process is switched
away from. The seconds component of the time is only zero for the
first second after the uptime is set, and the mostly-dead code was only
executed during this time. (This was slightly broken by using uptimes
instead of times relative to the Epoch -- in the original version the
seconds component of the time was only 0 for the first second after
the Epoch.)
In mi_switch(), moved the setting of switchticks to just after the
first (and now only) setting of switchtime. This setting used to be
delayed since a late setting was needed for the idle case and an early
setting was not needed. Now the early setting is needed so that
fork_exit() doesn't need to set either switchtime or switchticks.
Removed now-completely-rotted comment attached to this. Most of the
code described by the comment had already moved to sched_switch().
begin with sched_lock held but not recursed, so this variable was
always 0.
Removed fixup of sched_lock.mtx_recurse after context switches in
sched_switch(). Context switches always end with this variable in the
same state that it began in, so there is no need to fix it up. Only
sched_lock.mtx_lock really needs a fixup.
Replaced fixup of sched_lock.mtx_recurse in fork_exit() by an assertion
that sched_lock is owned and not recursed after it is fixed up. This
assertion much match the one in mi_switch(), and if sched_lock were
recursed then a non-null fixup of sched_lock.mtx_recurse would probably
be needed again, unlike in sched_switch(), since fork_exit() doesn't
return to its caller in the normal way.
with an mbuf until it is reclaimed. This is in contrast to tags that
vanish when an mbuf chain passes through an interface. Persistent tags
are used, for example, by MAC labels.
Add an m_tag_delete_nonpersistent function to strip non-persistent tags
from mbufs and use it to strip such tags from packets as they pass through
the loopback interface and when turned around by icmp. This fixes problems
with "tag leakage".
Pointed out by: Jonathan Stone
Reviewed by: Robert Watson
Contributed by: Thomaswuerfl@gmx.de
- In sched_prio(), adjust the run queue for threads which may need to move
to the current queue due to priority propagation .
- In sched_switch(), fix style bug introduced when the KSE support went in.
Columns are 80 chars wide, not 90.
- In sched_switch(), Fix the comparison in the idle case and explicitly
re-initialize the runq in the not propagated case.
- Remove dead code in sched_clock().
- In sched_clock(), If we're an IDLE class td set NEEDRESCHED so that threads
that have become runnable will get a chance to.
- In sched_runnable(), if we're not the IDLETD, we should not consider
curthread when examining the load. This mimics the 4BSD behavior of
returning 0 when the only runnable thread is running.
- In sched_userret(), remove the code for setting NEEDRESCHED entirely.
This is not necessary and is not implemented in 4BSD.
- Use the correct comparison in sched_add() when checking to see if an idle
prio task has had it's priority temporarily elevated.
