and release of the global page queues lock required to make the call.
Remove GIANT_REQUIRED from vm_hold_free_pages(). All of its VM operations
are properly synchronized.
count to prevent sockets from being garbage collected during
socket-specific system calls. This is the same approach used in
most VFS-specific system calls, as well as generic file descriptor
system calls such as read() and write().
To do this, add a utility function getsock(), which is logically
identical to getvnode() used for the same purpose in VFS. Unlike
fgetsock(), it returns with the file reference count elevated, but
no bump of the socket reference count. Replace matching calls to
fputsock() with fdrop().
This change is made to all socket system calls other than
sendfile() and accept(), but the approach should be applicable to
those system calls also.
This shaves about four mutex operations off of each of these
system calls, including send() and recv() variants, adding about
1% to pps on minimal UDP packets for UP using netblast, and 4% on
SMP.
Reviewed by: pjd
Extend it with a strategy method.
Add bufstrategy() which do the usual VOP_SPECSTRATEGY/VOP_STRATEGY
song and dance.
Rename ibwrite to bufwrite().
Move the two NFS buf_ops to more sensible places, add bufstrategy
to them.
Add inlines for bwrite() and bstrategy() which calls through
buf->b_bufobj->b_ops->b_{write,strategy}().
Replace almost all VOP_STRATEGY()/VOP_SPECSTRATEGY() calls with bstrategy().
trigger a socket creation race some some kind). Checking for non-NULL socket
and credential is not a bad idea anyway. Unfortunatly too late for the
release.
Reported & tested by: Gilbert Cao
MFC after: 2 weeks
vm_page_sleep_if_busy(). (The motivation being to transition
synchronization of the vm_page's PG_BUSY flag from the global page queues
lock to the per-object lock.)
two loops in agp_generic_bind_memory(). As an intended side-effect, all
of the calls to vm_page_wakeup() are now performed with the containing
vm object lock held.
that indicates that the caller does not want a page with its busy flag set.
In many places, the global page queues lock is acquired and released just
to clear the busy flag on a just allocated page. Both the allocation of
the page and the clearing of the busy flag occur while the containing vm
object is locked. So, the busy flag might as well never be set.
This flag gets set whenever the thread posts an event on the GEOM
event queue, and if the flag is set when the thread is prepared
to return to userland from the kernel, g_waitidle() will be called
to make sure that the posted events have completed.
This can replace an insufficient number of g_waitidle() calls in
various other places, and has the advantage of being failsafe: Any
system call which does a VOP_OPEN()/VOP_CLOSE will now correctly
wait for any geom events it posted as part of spoils or tastes.
Assert that topology and Giant is not held in g_waitidle().
or pru_attach is NULL. With loadable protocols the SPACER dummy protocols
have valid function pointers for all methods to functions returning just
EOPNOTSUPP. Thus the early abort check would not detect immediately that
attach is not supported for this protocol. Instead it would correctly
get the EOPNOTSUPP error later on when it calls the protocol specific
attach function.
Add testing against the pru_attach_notsupp() function pointer to the
early abort check as well.
the final set of traces -- someone with more busdma background
will probably want to review and expand this, as well as port to
other platforms. This tracing is sufficient to identify key
busdma events on i386, and in particular to draw attention to
bounce buffering events that may have a substantial performance
impact.
o Instead of locking and unlocking all over the place, use
lock assertions to make certain that the bfe lock is held
where necessary.
o Create locked and unlocked versions of bfe_init and bfe_start. These
functions can be called from outside the module and by functions
within the bfe module. The calls from outside the module don't
hold the bfe lock so the unlocked versions called by these functions
simple obtain the bfe lock and call the locked version.
- Fix a typo (scp) in the locking macros that only worked because in all the
instances in which it was called the softc pointer happened to be named 'sc'.
- Mark the interrupt MPSAFE
Tested by: matusita, Dario Freni <saturnero@gufi.org>
Silence from: -net, wpaul
