<li><p>Most SMP-related discussion takes place on the

	  <a href="mailto:freebsd-smp@FreeBSD.org">freebsd-smp</a>

	  mailing list.  You can read more about mailing lists in the

	  <a href="../doc/en_US.ISO8859-1/books/handbook/eresources.html#ERESOURCES-MAIL">

	  Resources on the Internet</a> appendix of the

	  <a href="../doc/en_US.ISO8859-1/books/handbook/index.html">FreeBSD Handbook</a>.</p></li>

      <li><p>Steve Passe has been maintaining a

	  <a href="http://people.FreeBSD.org/~fsmp/SMP/SMP.html">SMP

	  project page</a> that contains additional information, and

	  goes back further in time than this web page.</p></li>

      <li><p>&a.rwatson; is maintaining a page for SMP-related network

	  performance work for the <a href="../projects/netperf/">Netperf

	  project</a>.  In addition, he has a <a

	  href="http://www.watson.org/~robert/freebsd/netperf/">a personal

	  web page with a change log and other information</a>.</p></li>

      <li><p><a href="http://www.osnews.com/">OSNews</a> has run an

	interview with FreeBSD developers &a.rwatson;, &a.jhb;, and

	&a.scottl;, who talk about many features in 6.x, including recent

	SMPng work, SMPVFS, and more.  The <a

	href="http://www.osnews.com/story.php?news_id=10951">article is

	here</a>.</p></li>

      <li><p>A series of man pages on kernel synchronization and threading

	  primitives can be found here:</p>

	    <ul>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=mutex&amp;apropos=0&amp;sektion=9">Kernel Mutexes (mutex(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=mtx_pool&amp;apropos=0&amp;sektion=9">Kernel Mutex Pools (mtx_pool(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=critical&amp;apropos=0&amp;sektion=9">Kernel Critical Sections (critical(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=sx&amp;apropos=0&amp;sektion=9">Kernel Shared/Exclusive Locks (sx(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=condvar&amp;apropos=0&amp;sektion=9">Kernel Condition Variables (condvar(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=sema&amp;apropos=0&amp;sektion=9">Kernel Semaphores (sema(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=sleep&amp;apropos=0&amp;sektion=9">Kernel sleep/wakeup API (sleep(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=kthread&amp;apropos=0&amp;sektion=9">Kernel Threads (kthread(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=ithread&amp;apropos=0&amp;sektion=9">Interrupt Threads (ithread(9))</a></li>

	      <li><a href="http://www.freebsd.org/cgi/man.cgi?query=swi&amp;apropos=0&amp;sektion=9">Software Interrupt Threads (swi(9))</a></li>

	    </ul>

	  <br>

	  <p>In addition, the old <a href="http://www.freebsd.org/cgi/man.cgi?query=spl&amp;apropos=0&amp;sektion=9">SPL man page</a> may be of interest, as it reflects the previous SMP synchronization model.</p>

	</li>

      <li><p>

	  Hiten Pandya's <a

	  href="http://storm.uk.FreeBSD.org/~hiten/smp_synch_rules.html">

	  SMP kernel synchronization rules</a>.</p></li>

      <li><p>&a.dillon; maintained a

	  <a href="http://apollo.backplane.com/FreeBSDSmp/">web page</a>

	  that documented the work he was doing on the SMP project.</p></li>

	  <a href="http://www.usenix.org/events/bsdcon02/full_papers/baldwin/baldwin_html/index.html">

	  "Locking in the Multithreaded FreeBSD Kernel" USENIX paper by &a.jhb;</a>.

	</p>

      </li>

      <li>

	<p>

    </ul>

    <a name="subsystems"></a>

    <h2>Subsystems and Staffing (Historical)</h2>

    <p>This is an incomplete list of high-level kernel subsystems and

      current, active staff working on SMP architecture and stability.</p>

    <table class="tblbasic">

      <tr class="heading">

	<th> Subsystem </th>

	<th> Status </th>

	<th> Last updated </th>

	<th> Staffing </th>

      </tr>

      <tr>

	<td> Newbus </td>

	<td> &status.wip; </td>

	<td> 5 October 2003 </td>

	<td> &a.imp;</td>

      </tr>

      <tr>

	<td> VM </td>

	<td> &status.wip; </td>

	<td> 4 October 2003 </td>

	<td> &a.alc;</td>

      </tr>

      <tr>

	<td> Buffer cache </td>

	<td> &status.wip; </td>

	<td> 4 October 2003 </td>

	<td> &a.jeff;, &a.phk; </td>

      </tr>

      <tr>

	<td> VFS </td>

	<td> &status.done; </td>

	<td> 24 January 2005 </td>

	<td> &a.jeff; </td>

      </tr>

      <tr>

	<td> Processes and thread operations </td>

	<td> &status.wip; </td>

	<td> 5 May 2003 </td>

	<td> &a.jhb; </td>

      </tr>

      <tr>

	<td> Scheduler </td>

	<td> &status.done; </td>

	<td> 23 April 2004 </td>

	<td> &a.jhb;, &a.jeff; </td>

      </tr>

      <tr>

	<td> GEOM </td>

	<td> &status.done; </td>

	<td> 5 February 2003 </td>

	<td> &a.phk; </td>

      </tr>

      <tr>

	<td> File descriptors </td>

	<td> &status.done; </td>

	<td> 5 February 2003 </td>

	<td> &a.alfred;, &a.tanimura;, &a.rwatson; </td>

      </tr>

      <tr>

	<td> TTY subsystem </td>

	<td> &status.done; </td>

	<td> 20 August 2008 </td>

	<td> &a.ed; </td>

      </tr>

      <tr>

	<td> Pipe IPC </td>

	<td> &status.done; </td>

	<td> 4 October 2003 </td>

	<td> &a.alfred; </td>

      </tr>

      <tr>

	<td> Socket structures and system calls </td>

	<td> &status.done; </td>

	<td> 25 November 2004 </td>

	<td> &a.sam;, &a.rwatson; </td>

      </tr>

      <tr>

	<td> KQueue </td>

	<td> &status.done; </td>

	<td> 24 November 2004 </td>

	<td> &a.jmg;, &a.green; </td>

      </tr>

      <tr>

	<td> IPv4 </td>

	<td> &status.done; </td>

	<td> 23 April 2004 </td>

	<td> &a.jennifer;, &a.hsu;, &a.sam;, &a.rwatson;, &a.gnn; </td>

      </tr>

      <tr>

	<td> IPv6 </td>

	<td> &status.wip; </td>

	<td> 01 July 2005 </td>

	<td> &a.rwatson;, &a.gnn; </td>

      </tr>

      <tr>

	<td> IPX/SPX </td>

	<td> &status.done; </td>

	<td> 09 January 2005 </td>

	<td> &a.rwatson; </td>

      </tr>

      <tr>

	<td> netatalk </td>

	<td> &status.done; </td>

	<td> 02 February 2005 </td>

	<td> &a.rwatson; </td>

      </tr>

      <tr>

	<td> Network stack infrastructure </td>

	<td> &status.done; </td>

	<td> 28 August 2004 </td>

	<td> &a.hsu;, &a.sam;, &a.rwatson;, &a.mlaier;, &a.luigi;, Maurycy Pawlowski-Wieronski &lt;maurycy@fouk.org&gt;, &a.brooks;,

	  &a.rik; </td>

      </tr>

      <tr>

	<td> NFS Client </td>

	<td> &status.done; </td>

	<td> 19 May 2006 </td>

	<td> &a.mohans; </td>

      </tr>

      <tr>

	<td> NFS Server </td>

	<td> &status.wip; </td>

	<td> 24 February 2007 </td>

	<td> &a.rwatson;, &a.jeff; </td>

      </tr>

    </table>

    <a name="tasks"></a>

    <h2>Tasks (Historical)</h2>

    <p>Following is an incomplete list of general tasks.</p>

    <table class="tblbasic">

      <tr class="heading">

	<th> Task </th>

	<th> Responsible </th>

	<th> Last updated </th>

	<th> Status </th>

      </tr>

      <tr>

	<td> Convert the giant lock from spinning to blocking, add the

	  scheduler lock, add per-CPU idle processes. </td>

	<td> &a.dillon; </td>

	<td> 25 June 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Port the BSD/OS locking primitives (i386). </td>

	<td> &a.jake; </td>

	<td> 3 July 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Implement heavy-weight interrupt threads (i386). </td>

	<td> &a.grog; </td>

	<td> 3 August 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Rewrite the low level interrupt code (i386 UP). </td>

	<td> &a.grog; </td>

	<td> 3 August 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Demonstrated reasonable stability (self-hosted buildworld)

	  (i386 UP). </td>

	<td> -smp developers </td>

	<td> 12 August 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Port the BSD/OS locking primitives (alpha). </td>

	<td> &a.dfr; </td>

	<td> 24 August 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Stub out (disable) spl()s. </td>

	<td> &a.grog; </td>

	<td> 30 August 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Port the BSD/OS ktr code. </td>

	<td> &a.grog;, &a.jhb; </td>

	<td> 30 August 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Rewrite the low level interrupt code (i386 SMP). </td>

	<td> &a.jhb; </td>

	<td> 1 September 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Demonstrated reasonable stability (self-hosted buildworld)

	  (i386 SMP). </td>

	<td> -smp developers </td>

	<td> 6 September 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Demonstrated reasonable stability (self-hosted buildworld)

	  (alpha). </td>

	<td> -smp developers </td>

	<td> 6 September 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make malloc and friends thread-safe. </td>

	<td> &a.jasone; </td>

	<td> 10 September 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Implement msleep(), make tsleep() an msleep() wrapper. </td>

	<td> &a.jake; </td>

	<td> 11 September 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make fxp driver thread-safe. </td>

	<td> &a.cp; </td>

	<td> 17 September 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make mbuf's thread-safe. </td>

	<td> &a.bmilekic; </td>

	<td> 29 September 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock manager re-work. </td>

	<td> &a.jasone; </td>

	<td> 3 October 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Implement heavy-weight interrupt threads (alpha). </td>

	<td> &a.jhb;, &a.dfr; </td>

	<td> 5 October 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Rewrite the low level interrupt code (alpha). </td>

	<td> &a.dfr;, &a.jhb; </td>

	<td> 5 October 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Process accounting. </td>

	<td> &a.tegge;, &a.jhb; </td>

	<td> 5 October 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make ethernet drivers thread-safe. </td>

	<td> &a.wpaul; </td>

	<td> 15 October 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make the mutex headers mostly machine-independent. </td>

	<td> &a.jhb; </td>

	<td> 20 October 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Rename SMP_DEBUG to MUTEX_DEBUG. </td>

	<td> &a.jhb; </td>

	<td> 20 October 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Give each soft interrupt its own thread. </td>

	<td> &a.cp; </td>

	<td> 25 October 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make sf_bufs (sendfile(2)) thread-safe. </td>

	<td> &a.bmilekic; </td>

	<td> 5 November 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make the witness code work correctly. </td>

	<td> &a.jhb; </td>

	<td> 18 November 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Split the ktr-specific code out of db_interface.c. </td>

	<td> &a.jhb;  </td>

	<td> 15 December 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Convert the sio driver to using a spin mutex. </td>

	<td> &a.jhb; </td>

	<td> 18 December 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Implement condition variables. </td>

	<td> &a.jake;, &a.jasone; </td>

	<td> 15 January 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add a flag to mtx_init() (MTX_RECURSE) that denotes

	  whether a mutex is allowed to recurse. </td>

	<td> &a.bmilekic; </td>

	<td> 19 January 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make the zone allocator thread-safe. </td>

	<td> &a.des; </td>

	<td> 21 January 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Convert simplelocks to mutexes. </td>

	<td> &a.jasone; </td>

	<td> 24 January 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make kernel preemptive with respect to interrupts. </td>

	<td> &a.jake; </td>

	<td> 31 January 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Cleanup of mutex API. </td>

	<td> &a.bmilekic; </td>

	<td> 8 February 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Remove COM_LOCK. </td>

	<td> &a.markm; </td>

	<td> 11 February 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Merge various scheduling classes into one run queue.

	  Modify scheduler to support preemptable kernel. </td>

	<td> &a.jake; </td>

	<td> 11 February 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make priority propagation work correctly. </td>

	<td> &a.jake; </td>

	<td> 11 February 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make most of the interrupt thread code MI and shared

	  between hardware and software interrupts. </td>

	<td> &a.jhb; </td>

	<td> 18 February 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add protection to struct jail and jail-related functionality. </td>

	<td> &a.rwatson; </td>

	<td> 20 February 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Implement sx (shared/exclusive) locks. </td>

	<td> &a.jasone; </td>

	<td> 5 March 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Generalize/improve witness to handle more complex locking

	  primitives (mtx, sx). </td>

	<td> &a.jhb; </td>

	<td> 28 March 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Convert the allproc and proctree locks from lockmgr locks

	  to sx locks. </td>

	<td> &a.jhb; </td>

	<td> 28 March 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make mbuf system use condition variables instead of

	  msleep()/wakeup(). </td>

	<td> &a.bmilekic; </td>

	<td> 2 April 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Remove &lt;sys/mutex.h&gt; includes from other kernel

	  headers such as <vm/vm_zone.h>, <sys/resourcevar.h>,

	  &lt;sys/ucred.h&gt;, and &lt;sys/mbuf.h&gt;. </td>

	<td> &a.markm; </td>

	<td> 15 May 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Cleanup the various mp_machdep.c's, unify various SMP

	  API's such as IPI delivery, etc. </td>

	<td> &a.jhb; </td>

	<td> 15 May 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make most of the forward_* and forwarded_* functions MI. </td>

	<td> &a.jhb; </td>

	<td> 15 May 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Complete the MD support for SMP on the Alpha platform.</td>

	<td> &a.gallatin;, &a.dfr;, &a.jhb; </td>

	<td> 15 May 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Convert select() to use condition variables. </td>

	<td> &a.tanimura; </td>

	<td> 15 May 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add a "giant" lock around the VM subsystem. </td>

	<td> &a.alfred; </td>

	<td> 13 June 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Introduce a modified slab allocator for the mbuf subsystem. </td>

	<td> &a.bmilekic; </td>

	<td> 21 June 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add a witness_assert() function to handle lock assertions. </td>

	<td> &a.jhb; </td>

	<td> 27 June 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Extend sx locks to support try lock operations. </td>

	<td> &a.jhb; </td>

	<td> 27 June 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Document KTR. </td>

	<td> &a.jhb; </td>

	<td> 28 June 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make fork_return, fork_exit, ast, and userret MI. </td>

	<td> &a.jhb; </td>

	<td> 29 June 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make sched_lock's savecrit a per-process property saved

	  and restored in mi_switch and initialized in fork_exit. </td>

	<td> &a.jhb; </td>

	<td> 30 June 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make ast() loop. </td>

	<td> &a.jhb; </td>

	<td> 10 August 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add upgrade/downgrade sx lock operations. </td>

	<td> &a.kan;, &a.jasone; </td>

	<td> 13 August 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Implement semaphores. </td>

	<td> &a.jasone; </td>

	<td> 14 August 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add support for upgrade/downgrades in witness. </td>

	<td> &a.jhb; </td>

	<td> 23 August 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make most of cpu_wait() and cpu_exit() MI. </td>

	<td> &a.peter; </td>

	<td> 9 September 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Split NFS into client and server. </td>

	<td> &a.peter; </td>

	<td> 18 Oct 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock taskqueues. </td>

	<td> &a.arr;, &a.jhb; </td>

	<td> 25 October 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add a per-thread ucred reference. </td>

	<td> &a.jhb; </td>

	<td> 25 October 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make most of the per-CPU stuff MI. </td>

	<td> &a.jhb; </td>

	<td> 11 December 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make critical section saved state per-thread instead of per-lock

	  so that interlocking spin locks work properly. </td>

	<td> &a.jhb; </td>

	<td> 17 December 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Replace the APIC-specific imen_mtx with a MI-named icu_lock to

	  protect interrupt controllers and associated data within the kernel

	  for both i386 and alpha. </td>

	<td> &a.jhb; </td>

	<td> 20 December 2001 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Use the per-thread critical section nesting level in the mutex

	    and interrupt thread code to automatically determine when to not

	    preempt.  This makes the MTX_NOSWITCH, SWI_SWITCH, and

	    SWI_NOSWITCH flags obsolete as the kernel will be able to figure

	    out the proper behavior on its own. </td>

	<td> &a.jhb; </td>

	<td> 5 January 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock struct filedesc and struct file. </td>

	<td> &a.tanimura;, &a.alfred; </td>

	<td> 12 January 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock struct pgrp, struct session, and struct sigio. </td>

	<td> &a.tanimura; </td>

	<td> 23 February 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock pipe implementation, but not sigio/fown, VM interactions. </td>

	<td> &a.alfred; </td>

	<td> 27 February 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Move to explicit reference counting for soft vnode references.

	  </td>

	<td> &a.phk; </td>

	<td> 8 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Initialize mutex pools early enough that sx locks can be used

	  for VM. </td>

	<td> &a.green; </td>

	<td> 14 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

        <td> Place a global lock (sellock) around selinfo structures to fix a

          variety of lock order reversals, and make select() MP-safe. </td>

        <td> &a.alfred;, &a.davidc; </td>

        <td> 14 March 2002 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Push down Giant on read, write, pread, pwrite system calls,

	  acquiring Giant in the per-subsystem fileop layer for sockets, VFS,

	  etc.</td>

	<td> &a.alfred; </td>

	<td> 15 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock down kernel module structures. </td>

	<td> &a.arr; </td>

	<td> 18 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock down kernel linker globals.</td>

	<td> &a.arr; </td>

	<td> 18 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Rewrite kernel memory allocator to be a slab allocator that

	  uses per-cpu caches. </td>

	<td> &a.jeff; </td>

	<td> 21 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Replace incorrect use of MD critical section API to disable

	  interrupts with a specific interrupt disable API. </td>

	<td> &a.imp;, &a.dfr;, &a.benno;, &a.jhb; </td>

	<td> 21 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock down access to the shared p_args "process arguments"

	  structure through appropriate protection of that structure and

	  references to it. </td>

	<td> &a.mini; </td>

	<td> 31 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Move from flags/tsleep lock to sx locks to protect sysctl

	  tree from updates during sysctl operations. </td>

	<td> &a.mini; </td>

	<td> 1 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Create/port userland tool to manage KTR event dumps. </td>

	<td> &a.jake; </td>

	<td> 1 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Create MTX_SYSINIT and SX_SYSINIT macros that allow for

	  initializing locks that are subsystem independent. </td>

	<td> &a.arr; </td>

	<td> 2 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

 	<td> Lock down the global securelevel variable. </td>

	<td> &a.arr; </td>

	<td> 2 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make grow_stack() MI.  Possibly even a macro or inline. </td>

	<td> &a.alc; </td>

	<td> 6 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock use of p_fd, which otherwise can result in corrupted

	  p_fd panics during heavy operation.  Start with a global,

	  and move to per-proc locking. </td>

	<td> &a.alfred;, &a.tanimura; </td>

	<td> 8 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock struct pargs. </td>

	<td> &a.mini; </td>

	<td> 9 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock sysctl hierarchy. </td>

	<td> &a.mini; </td>

	<td> 9 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make {o,}sigreturn() MPSAFE. </td>

	<td> &a.alc; </td>

	<td> 11 April 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Rewrite kernel memory allocator so that Giant is not required

	  for malloc() or free(). </td>

	<td> &a.jeff; </td>

	<td> 2 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Replace complex shared/exclusive locking scheme in the VM

	  system with a purely exclusive lockmgr locking scheme, simplifying

	  locking and removing potential livelock/deadlock scenarios. </td>

	<td> &a.green;, &a.alc; </td>

	<td> 3 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Push down Giant into readv/writev system calls in style of

	  read/write/pread/pwrite once malloc no longer requires Giant in

	  the handling of iovec structures for uio. </td>

	<td> &a.alc; </td>

	<td> 9 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Push down Giant in mprotect(), minherit(), and madvise() so

	  that it is no longer acquired and released directly. </td>

	<td> &a.alc; </td>

	<td> 18 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Update suser() and p_can*() APIs to accept threads instead of

	  processes. </td>

	<td> &a.jhb; </td>

	<td> 18 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Broadly transition to td_ucred from p_ucred once KSE dependencies

	  are in place. </td>

	<td> &a.jhb; </td>

	<td> 18 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add a witness_sleep() check to uma_zalloc() to catch code

	  calling malloc() or uma_zalloc() while holding non-sleepable

	  locks. </td>

	<td> &a.jhb; </td>

	<td> 20 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Optimize UP support by changing spin locks to only perform

	  critical section enter and exits. </td>

	<td> &a.jhb; </td>

	<td> 21 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make sleep mutexes spin if the current lock holder is

	    executing on another CPU. </td>

	<td> &a.jhb; </td>

	<td> 21 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add support for the IA32 pause instruction to spin loops in

	  locks. </td>

	<td> &a.jhb; </td>

	<td> 21 May 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make KTRACE write into tracefiles asynchronously. </td>

	<td> &a.jhb; </td>

	<td> 7 June 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

        <td> Remove Giant from modnext(2), modfnext(2),

          modstat(2),and modfind(2).</td>

        <td> &a.arr; </td>

        <td> 25 June 2002 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Fix synchronization of TLB flushes and invlpg() on x86 SMP. </td>

	<td> &a.peter; </td>

	<td> 12 July 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add KTR(9) tracing for mutex contention. </td>

	<td> &a.iedowse; </td>

	<td> 26 Augist 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make cpu_coredump MI. </td>

	<td> &a.peter; </td>

	<td> 7 September 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add a subsystem lock to the accounting code. </td>

	<td> &a.arr; </td>

	<td> 11 September 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Allow KTR(9) to write trace records to alq(9) record facility.

	  </td>

	<td> &a.jeff; </td>

	<td> 22 September 2002 </tD>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Create mechanism in cdevsw structure to protect

	  thread-unsafe drivers. </td>

	<td> &a.phk; </td>

	<td> 27 September 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Fix SIGXPU and other #if 0'd things in mi_switch(). </td>

	<td> &a.jhb; </td>

	<td> 30 September 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock down TrustedBSD MAC implementation. </td>

	<td> &a.rwatson; </td>

	<td> 11 November 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock eventhandlers. </td>

	<td> &a.msmith;, &a.mini;, &a.jhb; </td>

	<td> 11 March 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Fix PHOLD() so that it blocks to guarantee PS_INMEM. </td>

	<td> &a.jhb; </td>

	<td> 22 April 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Fix various procfs_machdep.c to not use sched_lock. </td>

	<td> &a.jhb; </td>

	<td> 22 April 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock all references to process credentials and remove Giant

	  from process credential-related system calls. </td>

	<td> &a.jhb; </td>

	<td> 1 May 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Merge the procsig and sigacts structures, move the new sigacts

	  structure out of the U-area and add appropriate locking. </td>

	<td> &a.jhb; </td>

        <td> 13 May 2003 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Remove Giant from the kill() and killpg() system calls. </td>

	<td> &a.jhb; </td>

        <td> 13 May 2003 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Enhance the mutex pool implementation to allow creation and

	  use of multiple, dynamically allocated pools with adjustable pool

	  sizes and mutex options. </td>

	<td> &a.truckman; </td>

        <td> 16 July 2003 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Create mutex profiling tool for the kernel so as to measure

	  contention and behavior of kernel mutexes. </td>

	<td> &a.eivind;, &a.des; </td>

	<td> 31 March 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock down linker_file_t structures in the kernel linker.</td>

	<td> &a.arr; </td>

	<td> 19 June 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock pipe implementation: VM optimizations. </td>

	<td> &nbsp; </td>

	<td> 4 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

        <td> Reimplement i386 interrupt and SMP code so that SMP kernels

	  work on UP boxes and SMP can be enabled in GENERIC. </td>

        <td> &a.jhb; </td>

        <td> 3 November 2003 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

        <td> Implement generic turnstiles to use when blocking on non-sleepable

	  locks. </td>

        <td> &a.jhb; </td>

        <td> 11 November 2003 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Split witness_lock() into witness_checkorder() and

	  witness_lock().  witness_checkorder() would be called before

	  acquiring a lock to increase the changes of detecting and warning

	  about a reversal prior to deadlocking.  witness_lock() would

	  simply update witness' internal state to note that a lock has

	  been acquired. </td>

	<td> &a.jhb; </td>

	<td> 24 January 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock per-process resource limits. </td>

	<td> &a.mtm;, &a.jhb; </td>

	<td> 4 February 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

        <td> Implement a sleep queue abstraction to be used by both msleep()

	  and condition variables.  This new abstraction should use a hash

	  table of sleep queues with a spin lock on each sleep queue chain

	  similar to turnstile chain locks to make sched_lock finger

	  grained.</td>

        <td> &a.jhb; </td>

        <td> 27 February 2004 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

        <td> Remove Giant from jail(2). </td>

        <td> &a.arr;, &a.rwatson; </td>

        <td> 23 April 2004 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Add subsystem locking to NFSv2, NFSv3 server, permitting upcalls

	  and other network-related elements to run Giant-free. </td>

	<td> &a.rwatson; </td>

	<td> 24 July 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add KTR(9) tracing for UMA allocation/free events. </td>

	<td> &a.rwatson; </td>

	<td> 05 August 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add KTR(9) tracing for GEOM I/O events. </td>

	<td> &a.rwatson; </td>

	<td> 21 October 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add KTR(9) tracing for busdma events. </td>

	<td> &a.rwatson; </td>

	<td> 23 October 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add KTR(9) tracing for critical sections. </td>

	<td> &a.rwatson; </td>

	<td> 07 November 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Make the kernel fully preemptive. </td>

	<td> &a.jhb; </td>

	<td> 24 November 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock pipe implementation: sigio/fown-related evil. </td>

	<td> &a.alfred; </td>

	<td> 24 November 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

       <td> Lock down the SysV IPC code. </td>

	<td> &a.alfred; </td>

	<td> 24 November 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock contention measurement tool to measure heat of various

	  locks, including Giant, and permit more directed performance and

	  locking strategy optimization. </td>

	<td> &a.rwatson; </td>

	<td> 24 November 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add KTR(9) tracing to scheduler run queues. </td>

	<td> &a.jeff; </td>

	<td> 26 December 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Review locking strategy and correctness of VFS operations

	  and fix up various failure modes associated with enabling

	  VFS locking assertions. </td>

	<td> &a.jeff; </td>

	<td> 01 January 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Document in-vnode locking strategy, clean it up. </td>

	<td> &a.jeff; </td>

	<td> 01 January 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Run cross-file system VFS without Giant, acquiring Giant

	  conditionally based on a file system flag. </td>

	<td> &a.jeff; </td>

	<td> 01 January 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Run UFS file system MPSAFE. </td>

	<td> &a.jeff; </td>

	<td> 01 January 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add KTR(9) tracing for buffer cache events. </td>

	<td> &a.jeff; </td>

	<td> 24 January 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Break out critical section and spin lock APIs, and re-optimize

	  critical sections to not disable interrupts in hardware due to

	  the high cost on some hardware architectures. </td>

	<td> &a.jhb; </td>

	<td> 04 April 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Modify uma(9) to use critical sections to protect per-CPU

	  statistics, instead of mutexdes, in order to optimize access. </td>

	<td> &a.rwatson; </td>

	<td> 29 April 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Migrate malloc(9) to per-CPU statistics, and use critical

	  sections to optimize access to those statistics. </td>

	<td> &a.rwatson; </td>

	<td> 29 May 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add KTR(9) support for KTR_VFS to trace additional VFS events,

	  rather than mechanically inserted KTR_VOP events. </td>

	<td> &a.jeff; </td>

	<td> 11 June 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Push the grabbing of Giant into Linux i386 ABI system calls.</td>

	<td> &a.jhb; </td>

	<td> 13 July 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Push the grabbing of Giant into Linux AXP ABI system calls.</td>

	<td> &a.jhb; </td>

	<td> 13 July 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Push the grabbing of Giant into SVR4 i386 ABI system calls.</td>

	<td> &a.jhb; </td>

	<td> 13 July 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Push the grabbing of Giant into OSF/1 AXP ABI system calls.</td>

	<td> &a.jhb; </td>

	<td> 13 July 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Push the grabbing of Giant into IBCS i386 ABI system calls.</td>

	<td> &a.jhb; </td>

	<td> 13 July 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Add a new witness check for exiting threads to verify that

	  an exiting thread holds no locks. </td>

	<td> &a.jhb; </td>

	<td> 2 September 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

        <td> Implement atomic_fetchadd() for ints. </td>

        <td> &a.jhb; </td>

        <td> 27 September 2005 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

        <td> Implement a simple reference count API using atomic operations and

	  use this to replace locks that just protect a reference count. </td>

        <td> &a.jhb; </td>

        <td> 27 September 2005 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Split the interrupt handler list out of struct ithread into

	  its own structure and only start up kthreads for interrupt

	  vectors that actually have threaded interrupt handlers. </td>

	<td> &a.jhb; </td>

	<td> 25 October 2005 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock aio(4). </td>

	<td> &a.davidxu; </td>

	<td> 22 January 2006 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Implement reader/writer locks. </td>

	<td> &a.jhb; </td>

	<td> 27 January 2006 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

        <td> Remove the MPSAFE syscall flag from the syscall table. </td>

        <td> &a.jhb; </td>

        <td> 28 July 2006 </td>

        <td> &status.done; </td>

      </tr>

      <tr>

	<td> Add sufficient synchronization to printf to avoid printing

	  problems but not so much it doesn't work in debugging contexts. </td>

	<td> &a.jb; </td>

	<td> 1 November 2006 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Expand mutex profiling tool to also profile sx locks. </td>

	<td> &a.kmacy; </td>

	<td> 11 November 2006 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock down the TTY subsystem. </td>

	<td> &a.ed; </td>

	<td> 20 August 2008 </td>

	<td> &status.done; </td>

      </tr>

      <!-- WIP -->

      <tr>

	<td> Lock struct proc. </td>

	<td> &a.jhb; </td>

	<td> 20 February 2001 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Fix clock locking to be the same on all platforms. </td>

	<td> &a.jhb; </td>

	<td> 16 November 2001 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Make use of process locking and process reference counting

	  to protect debugging interfaces (and procfs). </td>

	<td> &a.jhb; </td>

	<td> 27 February 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Make use of process locking to protect process monitoring

	  sysctls, including those employed by 'ps' and related tools.

	<td> &a.jhb; </td>

	<td> 27 February 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Lock down newbus infrastructure to support driver

	  fine-graining. </td>

	<td> &a.imp; </td>

	<td> 28 February 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> SMPng architecture document. </td>

	<td> &a.jhb;, &a.rwatson; </td>

	<td> 28 February 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Move to shared lock for VOP_GETATTR() to reduce blocking during

	  frequent lightweight VFS operations.  Modify namei() to provide

	  a LOOKUP_SHARED flag to indicate when the lock required may be

	  shared instead of exclusive. </td>

	<td> &a.jeff; </td>

	<td> 11 March 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Document existing vm_map locking and verify it's correctness. </td>

	<td> &a.alc; </td>

	<td> 18 May 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Document existing vm_object locking and verify it's

	  correctness. </td>

	<td> &a.alc; </td>

	<td> 4 May 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Implement lazy interrupt thread switching (context

	  stealing) on i386. </td>

	<td> &a.bmilekic;, &a.kan; </td>

	<td> 10 December 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Implement lazy interrupt thread switching (context

	  stealing) on sparc64. </td>

	<td> &a.jake; </td>

	<td> 10 December 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Switch from using lockmgr in VM to using a mutex or exclusive

	  sxlock.  Push down Giant on all VM except for vm_object/VFS and

	  vm_page/pmap components. </td>

	<td> &a.alc; </td>

	<td> 10 December 2002 </td>

	<td> &status.wip; </td>

      </tr>

      <tr>

	<td> Modify device driver API to permit drivers to more easily

	  split "in interrupt context" and "in interrupt thread"

	  code so as to acknowledge interrupts faster.  This will permit

	  lower latency in interrupt handling. </td>

	<td> &a.piso; </td>

	<td> 24 February 2007 </td>

	<td> &status.wip; </td>

      </tr>

      <!-- Stalled -->

      <!-- Not Started -->

      <tr>

	<td> Conditionalize atomic ops in the SMP code that are used

	  for debugging statistics. </td>

	<td> &a.peter; </td>

	<td> 15 March 2001 </td>

	<td> &status.new; </td>

      </tr>

      <tr>

	<td> Axe schedcpu() in favor of event driven priority updates as

	  much as possible. </td>

	<td> &nbsp; </td>

	<td> 7 September 2001 </td>

	<td> &status.new; </td>

      </tr>

      <tr>

	<td> Fix *hold (e.g. crhold) to return reference to object. </td>

	<td> &nbsp; </td>

	<td> 7 September 2001 </td>

	<td> &status.new; </td>

      </tr>

      <tr>

	<td> Add witness checking for lockmgr locks. </td>

	<td> &nbsp; </td>

	<td> 7 September 2001 </td>

	<td> &status.new; </td>

      </tr>

      <tr>

	<td> Add ICU spin locks on ia64. </td>

	<td> &nbsp; </td>

	<td> 4 January 2002 </td>

	<td> &status.new; </td>

      </tr>

      <tr>

	<td> Add a witness_sleep() check to copyin/out() and s/fuword(). </td>

	<td> &a.jhb; </td>

	<td> 7 June 2002 </td>

	<td> &status.new; </td>

      </tr>

      <tr>

	<td> Remove Giant from mi_startup() and push Giant down into

	  individual SYSINIT functions.  Many SYSINIT functions probably do

	  not need Giant anyway. </td>

	<td> &nbsp; </td>

	<td> 21 October 2005 </td>

	<td> &status.new; </td>

      </tr>

<!--

      <tr>

        <td>  </td>

        <td> &nbsp; </td>

        <td> D M 2002 </td>

        <td> &status.new; </td>

      </tr>

-->

    </table>

    <p>This table lists the todo subtasks for multithreading the network

      stack.</p>

    <table class="tblbasic">

      <tr class="heading">

	<th> Task </th>

	<th> Responsible </th>

	<th> Last updated </th>

	<th> Status </th>

      </tr>

      <tr>

	<td> Protect network interface queues. </td>

	<td> &a.jlemon; </td>

	<td> 24 November 2000 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock up IP. </td>

	<td> &a.jennifer;, &a.hsu; </td>

	<td> 10 June 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock up TCP. </td>

	<td> &a.jennifer;, &a.hsu;, &a.sam;, &a.rwatson;</td>

	<td> 24 November 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock up UDP. </td>

	<td> &a.jennifer;, &a.hsu;, &a.rwatson; </td>

	<td> 24 November 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock ifaddr reference counts. </td>

	<td> &a.hsu; </td>

	<td> 18 December 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock up ifnet list. </td>

	<td> &a.hsu; </td>

	<td> 21 December 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock radix trees. </td>

	<td> &a.hsu; </td>

	<td> 23 December 2002 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock up ARP. </td>

	<td> &a.hsu; </td>

	<td> 16 January 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock up raw IP. </td>

	<td> &a.sam;, &a.rwatson; </td>

	<td> 24 July 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock divert sockets. </td>

	<td> &a.sam; </td>

	<td> 4 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock ipfw2. </td>

	<td> &a.sam; </td>

	<td> 4 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock DUMMYNET. </td>

	<td> &a.sam; </td>

	<td> 4 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock ethernet bridge. </td>

	<td> &a.sam; </td>

	<td> 4 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock IP fragment queues. </td>

	<td> &a.rwatson; </td>

	<td> 4 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock routing entries. </td>

	<td> &a.sam; </td>

	<td> 4 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock FAST_IPSEC. </td>

	<td> &a.sam; </td>

	<td> 4 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Permit parallel entry into isr processing. </td>

	<td> &a.rwatson;, &a.sam; </td>

	<td> 11 October 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock if_disc "discard interface". </td>

	<td> &a.rwatson; </td>

	<td> 9 March 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock if_faith "IPv6-to-IPv4 TCP relay interface. " </td>

	<td> &a.sam;, &a.rwatson; </td>

	<td> 9 March 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock if_gif "generic tunnel interface". </td>

	<td> &a.rwatson; </td>

	<td> 9 March 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Review ECN tunnel support (ip_ecn.c). </td>

	<td> &a.rwatson; </td>

	<td> 9 March 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> if_tap global and softc locking. </td>

	<td> &a.rwatson; </td>

	<td> 23 April 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> if_tun global and softc locking. </td>

	<td> &a.rwatson; </td>

	<td> 23 April 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> netatalk/aarp.c locking. </td>

	<td> &a.rwatson; </td>

	<td> 23 April 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Cache socket MAC label in inpcb label for IPv4 sockets so that

	  the label can be used safely at the inet layer without socket

	  locks. </tD>

	<td> &a.rwatson; </td>

	<td> 23 April 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> IP encapsulation subroutines (ip_encap.c). </td>

	<td> &a.rwatson; </td>

	<td> 23 April 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock globals in loopback interface (if_loop.c). </td>

	<td> &a.rwatson; </td>

	<td> 23 April 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Use m_tags in if_gif to limit looping configurations, rather

	  than a non-MPSAFE static coutner. </td>

	<td> &a.ru; </td>

	<td> 23 April 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> netatalk DDP PCB locking. </td>

	<td> &a.rwatson; </td>

	<td> 24 July 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock up syncache. </td>

	<td> &a.hsu;, &a.sam; </td>

	<td> 10 November 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Permit IP forwarding path to run Giant-free. </td>

	<td> &a.sam; </td>

	<td> 1 December 2003 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock &unix; domain protocols, fifofs. </td>

	<td> &a.sam;, &a.rwatson; </td>

	<td> 24 July 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Giant lock over NFS server to protect against so_upcall() w/o Giant </td>

	<td> &a.rwatson; </td>

	<td> 24 July 2004 </td>

	<td> &status.done; </td>

      </tr>

      <tr>

	<td> Lock interface cloning meta-data. </td>