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More cleanup.

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This commit is contained in:
brueffer 2007-11-11 19:40:46 +00:00
parent 208beedc88
commit 8febd76b4e
1 changed files with 14 additions and 12 deletions
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26
share/man/man9/rmlock.9
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@ -39,7 +39,7 @@
.Nm rm_wunlock ,
.Nm rm_wowned ,
.Nm RM_SYSINIT
.Nd mostly read lock - a kernel reader/writer lock optimized for mostly read access patterns
.Nd kernel reader/writer lock optimized for mostly read access patterns
.Sh SYNOPSIS
.In sys/param.h
.In sys/lock.h
@ -91,7 +91,8 @@ can be locked while holding a non-spin mutex, and an
cannot be held while sleeping.
The
.Nm
locks have full priority propagation like mutexes. The
locks have full priority propagation like mutexes.
The
.Va rm_priotracker
structure argument supplied in
.Fn rm_rlock
@ -113,19 +114,22 @@ as mostly reader lock, described by
Optionally allowing readers to recurse by setting
.Dv LO_RECURSABLE
in
.Fa opts
.Fa opts .
The name description is used solely for debugging purposes.
This function must be called before any other operations
on the lock.
.It Fn rm_rlock "struct rmlock *rm" "struct rm_priotracker* tracker"
.It Fn rm_rlock "struct rmlock *rm" "struct rm_priotracker* tracker"
Lock
.Fa rm
as a reader. Using
as a reader.
Using
.Fa tracker
to track read owners of a lock for priority propagation.
This data structure is only used internally by
.Nm
and must persist until rm_runlock has been called.
and must persist until
.Fn rm_runlock
has been called.
This data structure can be allocated on the stack since
rmlocks cannot be held while sleeping.
If any thread holds this lock exclusively, the current thread blocks,
@ -147,7 +151,7 @@ If there are any shared owners of the lock, the current thread blocks.
The
.Fn rm_wlock
function cannot be called recursively.
.It Fn rm_runlock "struct rmlock *rm" "struct rm_priotracker* tracker"
.It Fn rm_runlock "struct rmlock *rm" "struct rm_priotracker* tracker"
This function releases a shared lock previously acquired by
.Fn rm_rlock .
The
@ -169,12 +173,11 @@ This function returns a non-zero value if the current thread owns an
exclusive lock on
.Fa rm .
.El
.El
.Sh SEE ALSO
.Xr locking 9 ,
.Xr mutex 9 ,
.Xr panic 9 ,
.Xr rwlock 9,
.Xr rwlock 9 ,
.Xr sema 9 ,
.Xr sx 9
.Sh HISTORY
@ -192,16 +195,15 @@ This manual page was written by
for rwlock and modified to reflect rmlock by
.An "Stephan Uphoff" .
.Sh BUGS
.Pp
The
.Nm
implementation is currently not optimized for single processor systems.
.Pp
The
.Nm
implementation uses a single per cpu list shared by all
implementation uses a single per CPU list shared by all
rmlocks in the system.
If rmlocks become popular, hashing to multiple per cpu queues may
If rmlocks become popular, hashing to multiple per CPU queues may
be needed to speed up the writer lock process.
.Pp
The