Bug 132546

Summary: [patch] sync vm_map_lock(9) with recent locking changes
Product: Documentation Reporter: pluknet <pluknet>
Component: Books & ArticlesAssignee: Tom Rhodes <trhodes>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: Latest   
Hardware: Any   
OS: Any   
Attachments:
Description Flags
file.diff none

Description pluknet 2009-03-11 15:10:01 UTC 
Quoting commit log to vm_map.c, v1.402:

"Resurrect shared map locks allowing greater concurrency during some map
operations, such as page faults.
[..]
MFC after:	6 weeks"

vm_map_lock(9) was not updated to reflect the reality.

Fix: Apply the patch.



Patch attached with submission follows:
Comment 1 dfilter service freebsd_committer freebsd_triage 2009-04-04 00:53:02 UTC 
Author: trhodes
Date: Fri Apr  3 23:52:47 2009
New Revision: 190680
URL: http://svn.freebsd.org/changeset/base/190680

Log:
  Catch up with recent locking changes.
  
  PR:		132546
  Submitted by:	pluknet <pluknet@gmail.com>
  Reviewed by:	alc

Modified:
  head/share/man/man9/vm_map_lock.9

Modified: head/share/man/man9/vm_map_lock.9
==============================================================================
--- head/share/man/man9/vm_map_lock.9	Fri Apr  3 21:13:18 2009	(r190679)
+++ head/share/man/man9/vm_map_lock.9	Fri Apr  3 23:52:47 2009	(r190680)
@@ -73,7 +73,6 @@ The
 .Fn vm_map_lock_read
 macro obtains a read-lock on
 .Fa map .
-Currently this is implemented as an exclusive lock.
 .Pp
 The
 .Fn vm_map_unlock_read
@@ -93,23 +92,18 @@ macro attempts to obtain a read-lock on
 .Fa map .
 It returns FALSE if the lock cannot be immediately acquired;
 otherwise return TRUE with the lock acquired.
-Currently this is implemented as an exclusive lock.
 .Pp
 The
 .Fn vm_map_lock_upgrade
 macro attempts to atomically upgrade a read-lock on
 .Fa map
 to an exclusive lock.
-As read-locks are currently implemented as exclusive locks,
-this macro is a no-op.
 .Pp
 The
 .Fn vm_map_lock_downgrade
 macro attempts to downgrade an exclusive lock on
 .Fa map
 to a read-lock.
-As read-locks are currently implemented as exclusive locks,
-this macro is a no-op.
 .Sh IMPLEMENTATION NOTES
 Currently, all of the locking macros implement their locks as sleep locks.
 .Sh SEE ALSO
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Comment 2 Tom Rhodes freebsd_committer freebsd_triage 2009-04-04 00:56:59 UTC 
State Changed
From-To: open->patched

Patched in CURRENT, thanks!
Comment 3 Tom Rhodes freebsd_committer freebsd_triage 2009-04-04 00:56:59 UTC 
Responsible Changed
From-To: freebsd-doc->trhodes

Over to me, I'll MFC after Alan pushes the change to 7.
Comment 4 Tom Rhodes freebsd_committer freebsd_triage 2012-07-21 16:49:46 UTC 
State Changed
From-To: patched->closed

Changes have been merged for awhile now, thanks.