- Teach SCHED_4BSD to inform cpu_idle() about high sleep/wakeup rate to
choose optimized handler. In case of x86 it is MONITOR/MWAIT. Also it
will be needed to bypass forthcoming idle tick skipping logic to not
consume resources on events rescheduling when it won't give any benefits.
- Teach SCHED_4BSD to wake up idle CPUs without using IPI. In case of x86,
when MONITOR/MWAIT is active, it require just single memory write. This
doubles performance on some heavily switching test loads.
code associated with overflow or with the drain function. While this
function is not expected to be used often, it produces more information
in the form of an errno that sbuf_overflowed() did.
This reflects actual type used to store and compare child device orders.
Change is mostly done via a Coccinelle (soon to be devel/coccinelle)
semantic patch.
Verified by LINT+modules kernel builds.
Followup to: r212213
MFC after: 10 days
handlers, some of which had to do awkward things to get a large enough
FIXEDLEN buffer.
Note that some sysctl handlers were explicitly outputting a trailing NUL
byte. This behaviour was preserved, though it should not be necessary.
Reviewed by: phk
called when the sbuf internal buffer is filled. For kernel sbufs with a
drain, the internal buffer will never be expanded. For userland sbufs
with a drain, the internal buffer may still be expanded by
sbuf_[v]printf(3).
Sbufs now have three basic uses:
1) static string manipulation. Overflow is marked.
2) dynamic string manipulation. Overflow triggers string growth.
3) drained string manipulation. Overflow triggers draining.
In all cases the manipulation is 'safe' in that overflow is detected and
managed.
Reviewed by: phk (the previous version)
syscall and the same function, but are very different and share almost no code.
To make it easier to read and analyze, split vfs_domount() into
vfs_domount_first() and vfs_domount_update().
Reviewed by: kib
- Correct error paths. The system will be useless on devfs_fixup() failure, so
why bother? Maybe for the same reason why a dead body is washed and dressed
in a nice suit before it is put into a coffin? Maybe system's last will is to
panic without any locks held?
Reviewed by: kib
Also change int -> u_int for order parameter in device_add_child_ordered.
There should not be any ABI change as struct device is private to subr_bus.c
and the API change should be compatible.
To do: change int -> u_int for order parameter of bus_add_child method
and its implementations. The change should also be API compatible, but
is a bit more churn.
Suggested by: imp, jhb
MFC after: 1 week
Add the BIO_ORDERED flag for struct bio and update bio clients to use it.
The barrier semantics of bioq_insert_tail() were broken in two ways:
o In bioq_disksort(), an added bio could be inserted at the head of
the queue, even when a barrier was present, if the sort key for
the new entry was less than that of the last queued barrier bio.
o The last_offset used to generate the sort key for newly queued bios
did not stay at the position of the barrier until either the
barrier was de-queued, or a new barrier (which updates last_offset)
was queued. When a barrier is in effect, we know that the disk
will pass through the barrier position just before the
"blocked bios" are released, so using the barrier's offset for
last_offset is the optimal choice.
sys/geom/sched/subr_disk.c:
sys/kern/subr_disk.c:
o Update last_offset in bioq_insert_tail().
o Only update last_offset in bioq_remove() if the removed bio is
at the head of the queue (typically due to a call via
bioq_takefirst()) and no barrier is active.
o In bioq_disksort(), if we have a barrier (insert_point is non-NULL),
set prev to the barrier and cur to it's next element. Now that
last_offset is kept at the barrier position, this change isn't
strictly necessary, but since we have to take a decision branch
anyway, it does avoid one, no-op, loop iteration in the while
loop that immediately follows.
o In bioq_disksort(), bypass the normal sort for bios with the
BIO_ORDERED attribute and instead insert them into the queue
with bioq_insert_tail(). bioq_insert_tail() not only gives
the desired command order during insertion, but also provides
barrier semantics so that commands disksorted in the future
cannot pass the just enqueued transaction.
sys/sys/bio.h:
Add BIO_ORDERED as bit 4 of the bio_flags field in struct bio.
sys/cam/ata/ata_da.c:
sys/cam/scsi/scsi_da.c
Use an ordered command for SCSI/ATA-NCQ commands issued in
response to bios with the BIO_ORDERED flag set.
sys/cam/scsi/scsi_da.c
Use an ordered tag when issuing a synchronize cache command.
Wrap some lines to 80 columns.
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
sys/geom/geom_io.c
Mark bios with the BIO_FLUSH command as BIO_ORDERED.
Sponsored by: Spectra Logic Corporation
MFC after: 1 month
thread in a racy manner, which can lead to attempting to migrate a
thread that is pinned to a CPU. Instead, have sched_switch() determine
which CPU a thread should run on if the current one is not allowed.
KASSERT in sched_bind() that the thread is not yet pinned to a CPU.
KASSERT in sched_switch() that only migratable threads or those moving
due to a sched_bind() are changing CPUs.
sched_affinity code came from jhb@.
MFC after: 2 weeks
- add rm_try_rlock().
- add RM_SLEEPABLE to use sx(9) as the back-end lock in order to sleep while
holding the write lock.
- change rm_noreadtoken to a cpu bitmask to indicate which CPUs need to go
through the lock/unlock in order to synchronize. As a side effect, this
also avoids IPI to CPUs without any readers during rm_wlock.
Discussed with: ups@, rwatson@ on arch@
Sponsored by: Isilon Systems, Inc.
signals, because it is managed by debugger, however a normal signal sent to
a interruptibly sleeping thread wakes up the thread so it will handle the
signal when the process leaves the stopped state.
PR: 150138
MFC after: 1 week
least one execute bit set, otherwise execve(2) will return EACCES even
for an user with PRIV_VFS_EXEC privilege.
Add the check also to vaccess(9), vaccess_acl_nfs4(9) and
vaccess_acl_posix1e(9). This makes access(2) to better agree with
execve(2). Because ZFS doesn't use vaccess(9) for VEXEC, add the check
to zfs_freebsd_access() too. There may be other file systems which are
not using vaccess*() functions and need to be handled separately.
PR: kern/125009
Reviewed by: bde, trasz
Approved by: pjd (ZFS part)
for socket, when specified POLLIN|POLLOUT in events, you would have one
selfd registered for receiving socket buffer, and one for sending. Now,
if both events are not ready to fire at the time of the initial scan,
but are simultaneously ready after the sleep, pollrescan() would iterate
over the pollfd struct twice. Since both times revents is not zero,
returned value would be off by one.
Fix this by recalculating the return value in pollout().
PR: kern/143029
MFC after: 2 weeks
Actually it is hard to properly handle such a failure, especially in MNT_UPDATE
case. The only reason for the vfs_allocate_syncvnode() function to fail is
getnewvnode() failure. Fortunately it is impossible for current implementation
of getnewvnode() to fail, so we can assert this and make
vfs_allocate_syncvnode() void. This in turn free us from handling its failures
in the mount code.
Reviewed by: kib
MFC after: 1 month
rather than forging ahead and interpreting garbage buffer content
and dirent structures.
This change backs out r211684 which was essentially a no-op.
MFC after: 1 week
standard kill(). On other systems, SI_LWP is generated by lwp_kill().
This will allow conforming applications to differentiate between
signals generated by standard events and those generated by other
implementation events in a manner compatible with existing practice.
- Bump __FreeBSD_version
the uio_offset adjustment instead to calculate a correct *len.
Without this change, we run off the end of the directory data
we're reading and panic horribly for nfs filesystems.
MFC after: 1 week
use '-' in probe names, matching the probe names in Solaris.[1]
Add userland SDT probes definitions to sys/sdt.h.
Sponsored by: The FreeBSD Foundation
Discussed with: rwaston [1]
LK_CANRECURSE after a lock is created. Use them to implement macros that
otherwise manipulated the flags directly. Assert that the associated
lockmgr lock is exclusively locked by the current thread when manipulating
these flags to ensure the flag updates are safe. This last change required
some minor shuffling in a few filesystems to exclusively lock a brand new
vnode slightly earlier.
Reviewed by: kib
MFC after: 3 days
