need for most calls to vm_page_busy(). Specifically, most calls to
vm_page_busy() occur immediately prior to a call to vm_page_remove().
In such cases, the containing vm object is locked across both calls.
Consequently, the setting of the vm page's PG_BUSY flag is not even
visible to other threads that are following the synchronization
protocol.
This change (1) eliminates the calls to vm_page_busy() that
immediately precede a call to vm_page_remove() or functions, such as
vm_page_free() and vm_page_rename(), that call it and (2) relaxes the
requirement in vm_page_remove() that the vm page's PG_BUSY flag is
set. Now, the vm page's PG_BUSY flag is set only when the vm object
lock is released while the vm page is still in transition. Typically,
this is when it is undergoing I/O.
control the number of lines per page rather than a constant. The variable
can be examined and changed in ddb as '$lines'. Setting the variable to
0 will effectively turn off paging.
- Change db_putchar() to force out pending whitespace before outputting
newlines and carriage returns so that one can rub out content on the
current line via '\r \r' type strings.
- Change the simple pager to rub out the --More-- prompt explicitly when
the routine exits.
- Add some aliases to the simple pager to make it more compatible with
more(1): 'e' and 'j' do a single line. 'd' does half a page, and
'f' does a full page.
MFC after: 1 month
Inspired by: kris
This is magic and no other operating system do so (i.e. Solaris, Tru64,
Linux, AIX, HP-UX, Irix, MacOS X, NetBSD).
Discussed on: current@
Reported by: S³awek ¯ak <zaks@prioris.mini.pw.edu.pl>
for modules linked into the kernel or loaded very early, panics will
result otherwise, as the CV code it calls will panic due to its use
of a mutex before it is initialized.
outside of the nice threshold due to a recently awoken thread with a
lower nice value. This further reduces the amount of time a positively
niced thread gets while running in conjunction with a workload that has
many short sleeps (ie buildworld).
check for TD_ON_RUNQ() no longer means the thread is really on a run-
queue. I suspect this state should be re-evaluated as it must mean
something else now. This fixes ULE+KSE+PREEMPTION on UP x86.
At some point later the syncer will unlearn about vnodes and the filesystems
method called by the syncer will know enough about what's in bo_private to
do the right thing.
[1] Ok, I know, but I couldn't resist the pun.
buf->b-dev.
Put a bio between the buf passed to dev_strategy() and the device driver
strategy routine in order to not clobber fields in the buf.
Assert copyright on vfs_bio.c and update copyright message to canonical
text. There is no legal difference between John Dysons two-clause
abbreviated BSD license and the canonical text.
an inordinate amount of synchronous console output that is fairly
undesirable on slower serial console. It's easily hit by accident
when frobbing other sysctls late at night.
Give ffs it's own bufobj->bo_ops vector and create a private strategy
routine, (currently misnamed for forwards compatibility), which is
just a copy of the generic bufstrategy routine except we call
softdep_disk_prewrite() directly instead of through the buf_prewrite()
indirection.
Teach UFS about the need for softdep_disk_prewrite() and call the
function directly in FFS.
Remove buf_prewrite() from the default bufstrategy() and from the
global bio_ops method vector.
We keep si_bsize_phys around for now as that is the simplest way to pull
the number out of disk device drivers in devfs_open(). The correct solution
would be to do an ioctl(DIOCGSECTORSIZE), but the point is probably mooth
when filesystems sit on GEOM, so don't bother for now.
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().
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.
without a mountpoint. In this scenario, there's no useful source for
a label on the vnode, since we can't query the mountpoint for the
labeling strategy or default label.
jest, of most excellent fancy: he hath taught me lessons a thousand
times; and now, how abhorred in my imagination it is! my gorge rises
at it. Here were those hacks that I have curs'd I know not how
oft. Where be your kludges now? your workarounds? your layering
violations, that were wont to set the table on a roar?
Move the skeleton of specfs into devfs where it now belongs and
bury the rest.
Initialize b_bufobj for all buffers.
Make incore() and gbincore() take a bufobj instead of a vnode.
Make inmem() local to vfs_bio.c
Change a lot of VI_[UN]LOCK(bp->b_vp) to BO_[UN]LOCK(bp->b_bufobj)
also VI_MTX() to BO_MTX(),
Make buf_vlist_add() take a bufobj instead of a vnode.
Eliminate other uses of bp->b_vp where bp->b_bufobj will do.
Various minor polishing: remove "register", turn panic into KASSERT,
use new function declarations, TAILQ_FOREACH_SAFE() etc.
Add bufobj_wref(), bufobj_wdrop() and bufobj_wwait() to handle the write
count on a bufobj. Bufobj_wdrop() replaces vwakeup().
Use these functions all relevant places except in ffs_softdep.c where
the use if interlocked_sleep() makes this impossible.
Rename b_vnbufs to b_bobufs now that we touch all the relevant files anyway.
