svn commit: r252209 - in head: share/man/man9 sys/kern sys/sys

[Attilio Rao]

On Thu, Jun 27, 2013 at 4:34 PM, John Baldwin <jhb at freebsd.org> wrote:
> On Wednesday, June 26, 2013 3:26:38 am Andre Oppermann wrote:
>> On 25.06.2013 20:44, John Baldwin wrote:
>> > Author: jhb
>> > Date: Tue Jun 25 18:44:15 2013
>> > New Revision: 252209
>> > URL: http://svnweb.freebsd.org/changeset/base/252209
>> >
>> > Log:
>> >    Several improvements to rmlock(9).  Many of these are based on patches
>> >    provided by Isilon.
>> >    - Add an rm_assert() supporting various lock assertions similar to other
>> >      locking primitives.  Because rmlocks track readers the assertions are
>> >      always fully accurate unlike rw_assert() and sx_assert().
>> >    - Flesh out the lock class methods for rmlocks to support sleeping via
>> >      condvars and rm_sleep() (but only while holding write locks), rmlock
>> >      details in 'show lock' in DDB, and the lc_owner method used by
>> >      dtrace.
>> >    - Add an internal destroyed cookie so that API functions can assert
>> >      that an rmlock is not destroyed.
>> >    - Make use of rm_assert() to add various assertions to the API (e.g.
>> >      to assert locks are held when an unlock routine is called).
>> >    - Give RM_SLEEPABLE locks their own lock class and always use the
>> >      rmlock's own lock_object with WITNESS.
>> >    - Use THREAD_NO_SLEEPING() / THREAD_SLEEPING_OK() to disallow sleeping
>> >      while holding a read lock on an rmlock.
>>
>> Thanks!
>>
>> Would it make sense to move struct rm_queue from struct pcpu itself to
>> using DPCPU as a next step?
>
> Perhaps.  It might make pcpu.h cleaner, aside from that concern I don't think
> it really matters much.

It cannot for performance reasons. I had a comment ready for this but
I'm not sure if it was ever committed.

Attilio


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