adds probes for mutexes, reader/writer and shared/exclusive locks to
gather contention statistics and other locking information for
dtrace scripts, the lockstat(1M) command and other potential
consumers.
Reviewed by: attilio jhb jb
Approved by: gnn (mentor)
that DTrace uses.
This fixes a bug that would have affected kernels built with MAC and all
kernels built after the mpsafetty integration.
The bug will be apparent in RELENG7 on MAC kernels.
Reported by: kan
After I removed all the unit2minor()/minor2unit() calls from the kernel
yesterday, I realised calling minor() everywhere is quite confusing.
Character devices now only have the ability to store a unit number, not
a minor number. Remove the confusion by using dev2unit() everywhere.
This commit could also be considered as a bug fix. A lot of drivers call
minor(), while they should actually be calling dev2unit(). In -CURRENT
this isn't a problem, but it turns out we never had any problem reports
related to that issue in the past. I suspect not many people connect
more than 256 pieces of the same hardware.
Reviewed by: kib
we free memory from underneath them.
This fixes an occasional panic I've been seeing in softclock() where a bad
pointer would be encountered when pushing DTrace hard.
Except for the case where we use the cloner library (clone_create() and
friends), there is no reason to enforce a unique device minor number
policy. There are various drivers in the source tree that allocate unr
pools and such to provide minor numbers, without using them themselves.
Because we still need to support unique device minor numbers for the
cloner library, introduce a new flag called D_NEEDMINOR. All cdevsw's
that are used in combination with the cloner library should be marked
with this flag to make the cloning work.
This means drivers can now freely use si_drv0 to store their own flags
and state, making it effectively the same as si_drv1 and si_drv2. We
still keep the minor() and dev2unit() routines around to make drivers
happy.
The NTFS code also used the minor number in its hash table. We should
not do this anymore. If the si_drv0 field would be changed, it would no
longer end up in the same list.
Approved by: philip (mentor)
(Don't ask for a vendor import of this yet, we're in the early days of svn)
Instead of using cyclic timers to call the state clean and deadman callbacks,
use a callout on FreeBSD to avoid the deadlock on FreeBSD due to trying to
send interprocessor interrupts with interrupts disabled.
Reported by: ps, jhb, peter, thompsa
