- Introduce a finit() which is used to initailize the fields of struct file
in such a way that the ops vector is only valid after the data, type,
and flags are valid.
- Protect f_flag and f_count with atomic operations.
- Remove the global list of all files and associated accounting.
- Rewrite the unp garbage collection such that it no longer requires
the global list of all files and instead uses a list of all unp sockets.
- Mark sockets in the accept queue so we don't incorrectly gc them.
Tested by: kris, pho
machine-independent support for superpages. (The earlier part was
the rewrite of the physical memory allocator.) The remainder of the
code required for superpages support is machine-dependent and will
be added to the various pmap implementations at a later date.
Initially, I am only supporting one large page size per architecture.
Moreover, I am only enabling the reservation system on amd64. (In
an emergency, it can be disabled by setting VM_NRESERVLEVELS to 0
in amd64/include/vmparam.h or your kernel configuration file.)
so that the results end up in the DDB output stream rather than the
console output stream.
This should likely also be done for the vprint() function it calls.
MFC after: 3 months
This option just adds complexity and the new implementation no longer
will support it, so axing it now that it is unused is probabilly the
better idea.
FreeBSD version is bumped in order to reflect the KPI breakage introduced
by this patch.
In the ports tree, kris found that only old OSKit code uses it, but as
it is thought to work only on 2.x kernels serie, version bumping will
solve any problem.
with the interlock), owner of the lock should be only curthread or at
least, for its limited usage, NULL which identifies LK_KERNPROC.
The thread "extra argument" for the lockmgr interface is going to be
removed in the near future, but for the moment, just let kernel run for
some days with this check on in order to find potential deadlocking
places around the kernel and fix them.
p_candebug() will return EAGAIN which, if the other process never
leaves execve(), will result in the sysctl spinning and never returning
to userspace. Processes should always eventually leave execve(), but
spinning in kernel while we wait is bad for countless reasons, and
particularly harmful if execve() itself is deadlocked.
Possibly we should return another error, or return a marker indicating
the thread is in execve() so it can be reported that way in userspace.
Reported by: kris
equivalent with this and so operate the switch.
That call is the only one remaining LK_EXCLUPGRADE consumer and removing
it will prepare the ground for LK_EXCLUPGRADE axing and further
lockmgr improvements.
Discussed with: jeff, ups
mounted FS' problems. These are more along the lines of 'avoiding an
avoidable panic' than a complete solution to removable devices. We
now close the barn door after the horse has gotten lose and has been
hit by a truck, as it were. The barn no longer catches fire in this
case, but the horse is still dead :-).
The vfs_bio.c fix causes us not to put a failed write back into the
dirty pool if the error returned was ENXIO. In that case, the buffer
is treated like any other clean buffer that's being retured. ENXIO
means the device isn't there anymore and will never be there again in
the future, so retrying is futile.
The vfs_mount.c fix treats 'ENXIO' as success for unmounting a file
system. If the device is gone, retrying later won't help and we'll
never be able to unmount the device.
These two are part of a larger patch set submitted by the author. The
other patches will be forth coming. I added comments to these two
patches.
Submitted by: Henrik Gulbrandsen
Reviewed by: phk@
PR: usb/46176 (partial)
dump using mechanically generated/extracted debugging output rather than
a simple memory dump. Current sources of debugging output are:
- DDB output capture buffer, if there is captured output to save
- Kernel message buffer
- Kernel configuration, if included in kernel
- Kernel version string
- Panic message
Textdumps are stored in swap/dump partitions as with regular dumps, but
are laid out as ustar files in order to allow multiple parts to be stored
as a stream of sequentially written blocks. Blocks are written out in
reverse order, as the size of a textdump isn't known a priori. As with
regular dumps, they will be extracted using savecore(8).
One new DDB(4) command is added, "textdump", which accepts "set",
"unset", and "status" arguments. By default, normal kernel dumps are
generated unless "textdump set" is run in order to schedule a textdump.
It can be canceled using "textdump unset" to restore generation of a
normal kernel dump.
Several sysctls exist to configure aspects of textdumps;
debug.ddb.textdump.pending can be set to check whether a textdump is
pending, or set/unset in order to control whether the next kernel dump
will be a textdump from userspace.
While textdumps don't have to be generated as a result of a DDB script
run automatically as part of a kernel panic, this is a particular useful
way to use them, as instead of generating a complete memory dump, a
simple transcript of an automated DDB session can be captured using the
DDB output capture and textdump facilities. This can be used to
generate quite brief kernel bug reports rich in debugging information
but not dependent on kernel symbol tables or precisely synchronized
source code. Most textdumps I generate are less than 100k including
the full message buffer. Using textdumps with an interactive debugging
session is also useful, with capture being enabled/disabled in order to
record some but not all of the DDB session.
MFC after: 3 months
kern.console format as is. Thus, no difference in output format should
appear after this commit.
Reviewed by: cognet@ (mentor)
Approved by: cognet@ (mentor)
for that argument. This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.
Assign approximate why values to all current consumers of the
kdb_enter() interface.
details from consumers.
- Track individual selecters on a per-descriptor basis such that there
are no longer collisions and after sleeping for events only those
descriptors which triggered events must be rescaned.
- Protect the selinfo (per descriptor) structure with a mtx pool mutex.
mtx pool mutexes were chosen to preserve api compatibility with
existing code which does nothing but bzero() to setup selinfo
structures.
- Use a per-thread wait channel rather than a global wait channel.
- Hide select implementation details in a seltd structure which is
opaque to the rest of the kernel.
- Provide a 'selsocket' interface for those kernel consumers who wish to
select on a socket when they have no fd so they no longer have to
be aware of select implementation details.
Tested by: kris
Reviewed on: arch
the ABI when enabled. There is no longer an embedded lock_profile_object
in each lock. Instead a list of lock_profile_objects is kept per-thread
for each lock it may own. The cnt_hold statistic is now always 0 to
facilitate this.
- Support shared locking by tracking individual lock instances and
statistics in the per-thread per-instance lock_profile_object.
- Make the lock profiling hash table a per-cpu singly linked list with a
per-cpu static lock_prof allocator. This removes the need for an array
of spinlocks and reduces cache contention between cores.
- Use a seperate hash for spinlocks and other locks so that only a
critical_enter() is required and not a spinlock_enter() to modify the
per-cpu tables.
- Count time spent spinning in the lock statistics.
- Remove the LOCK_PROFILE_SHARED option as it is always supported now.
- Specifically drop and release the scheduler locks in both schedulers
since we track owners now.
In collaboration with: Kip Macy
Sponsored by: Nokia
on 1/2 of each of the successive limits tied to the limit for
2k clusters.
- Adds real functionality in so that doing a sysctl to change these
actually changes them :-)
MFC after: 1 week
when applicable.
Aquire Giant slightly later for vnlru.
In the syncer, aquire the Giant only when a vnode belongs to the
non-MPsafe fs.
In both speedup_syncer() and syncer_shutdown(), remove the syncer thread from
the lbolt sleep queue after the syncer state is modified, not before.
Herded by: attilio
Tested by: Peter Holm
Reviewed by: ups
MFC after: 1 week
This makes updates mounts such as:
"mount -u -o rdonly" work more like, "mount -u -o ro".
References to "-o rdonly" were changed to "-o ro" in revision 1.60 of
the mount(8) man page,
but some people still like to use "-o rdonly" since it was documented
in earlier versions of FreeBSD.
Requested by: rwatson
MFC after: 1 week
within the jail are never freed. si_cred is only used by the MAC framework so
make the cred reference conditional on it being compiled in, this is not a fix
and will need to be reviewed for any new consumers of si_cred.
This will quell some user complaint when using jails with a default kernel.
Reviewed by: rwatson
MFC after: 3 days
dereferencing. Unaligned access could cause panic on strict alignment
architectures.
Reviewed by: marcel, marius (also tested on sparc64, thanks !)
MFC after: 3 days
support its -k argument:
kern.proc.kstack - dump the kernel stack of a process, if debugging
is permitted.
This sysctl is present if either "options DDB" or "options STACK" is
compiled into the kernel. Having support for tracing the kernel
stacks of processes from user space makes it much easier to debug
(or understand) specific wmesg's while avoiding the need to enter
DDB in order to determine the path by which a process came to be
blocked on a particular wait channel or lock.
- Introduce per-architecture stack_machdep.c to hold stack_save(9).
- Introduce per-architecture machine/stack.h to capture any common
definitions required between db_trace.c and stack_machdep.c.
- Add new kernel option "options STACK"; we will build in stack(9) if it is
defined, or also if "options DDB" is defined to provide compatibility
with existing users of stack(9).
Add new stack_save_td(9) function, which allows the capture of a stacktrace
of another thread rather than the current thread, which the existing
stack_save(9) was limited to. It requires that the thread be neither
swapped out nor running, which is the responsibility of the consumer to
enforce.
Update stack(9) man page.
Build tested: amd64, arm, i386, ia64, powerpc, sparc64, sun4v
Runtime tested: amd64 (rwatson), arm (cognet), i386 (rwatson)
its -f and -v arguments:
kern.proc.filedesc - dump file descriptor information for a process, if
debugging is permitted, including socket addresses, open flags, file
offsets, file paths, etc.
kern.proc.vmmap - dump virtual memory mapping information for a process,
if debugging is permitted, including layout and information on
underlying objects, such as the type of object and path.
These provide a superset of the information historically available
through the now-deprecated procfs(4), and are intended to be exported
in an ABI-robust form.
linker interfaces for looking up function names and offsets from
instruction pointers. Create two variants of each call: one that is
"DDB-safe" and avoids locking in the linker, and one that is safe for
use in live kernels, by virtue of observing locking, and in particular
safe when kernel modules are being loaded and unloaded simultaneous to
their use. This will allow them to be used outside of debugging
contexts.
Modify two of three current stack(9) consumers to use the DDB-safe
interfaces, as they run in low-level debugging contexts, such as inside
lockmgr(9) and the kernel memory allocator.
Update man page.
information in support of DDB(4); these functions bypass normal linker
locking as they may run in contexts where locking is unsafe (such as the
kernel debugger).
Add a new interface linker_ddb_search_symbol_name(), which looks up a
symbol name and offset given an address, and also
linker_search_symbol_name() which does the same but *does* follow the
locking conventions of the linker.
Unlike existing functions, these functions place the name in a
caller-provided buffer, which is stable even after linker locks have been
released. These functions will be used in upcoming revisions to stack(9)
to support kernel stack trace generation in contexts as part of a live,
rather than suspended, kernel.
per-cpu area. cp_time[] goes away and a new function creates a merged
cp_time-like array for things like linprocfs, sysctl etc. The
atomic ops for updating cp_time[] in statclock go away, and the scope
of the thread lock is reduced.
sysctl kern.cp_time returns a backwards compatible cp_time[] array.
A new kern.cp_times sysctl returns the individual per-cpu stats.
I have pending changes to make top and vmstat optionally show per-cpu
stats.
I'm very aware that there are something like 5 or 6 other versions "out
there" for doing this - but none were handy when I needed them.
I did merge my changes with John Baldwin's, and ended up replacing a
few chunks of my stuff with his, and stealing some other code.
Reviewed by: jhb
Partly obtained from: jhb
Currently, Giant is not too much contented so that it is ok to treact it
like any other mutexes.
Please don't forget to update your own custom config kernel files.
Approved by: cognet, marcel (maintainers of arches where option is
not enabled at the moment)
currently, before to spin the turnstile spinlock is acquired and the
waiters flag is set.
This is not strictly necessary, so just spin before to acquire the
spinlock and to set the flags.
This will simplify a lot other functions too, as now we have the waiters
flag set only if there are actually waiters.
This should make wakeup/sleeping couplet faster under intensive mutex
workload.
This also fixes a bug in rw_try_upgrade() in the adaptive case, where
turnstile_lookup() will recurse on the ts_lock lock that will never be
really released [1].
[1] Reported by: jeff with Nokia help
Tested by: pho, kris (earlier, bugged version of rwlock part)
Discussed with: jhb [2], jeff
MFC after: 1 week
[2] John had a similar patch about 6.x and/or 7.x about mutexes probabilly
should never be moved by one lock to another.
As, luckily, nothing in our tree is using it, axe the function.
This breaks lockmgr KPI, so interested, third-party modules should update
their source code with appropriate replacement.
Ok'ed by: ups, rwatson
MFC after: 3 days
