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author | Gordon Bergling <gbe@FreeBSD.org> | 2020-12-05 11:18:37 +0000 |
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committer | Gordon Bergling <gbe@FreeBSD.org> | 2020-12-05 11:18:37 +0000 |
commit | 2f3e7fb2cc8ddbc20711e82809430bf7c5eb88b3 (patch) | |
tree | d7ee8bd6fb11587fddaf6df2971039abd333a5d4 /share | |
parent | 935b2ac1f11515ec247712824a1f7911011763d5 (diff) | |
download | src-test2-2f3e7fb2cc8ddbc20711e82809430bf7c5eb88b3.tar.gz src-test2-2f3e7fb2cc8ddbc20711e82809430bf7c5eb88b3.zip |
epoch(9): Fix a few mandoc related issues
- sections out of conventional order: Sh EXAMPLES
- sections out of conventional order: Sh SEE ALSO
- skipping end of block that is not open: El
Notes
Notes:
svn path=/head/; revision=368368
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man9/epoch.9 | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/share/man/man9/epoch.9 b/share/man/man9/epoch.9 index 70ab8d799ed5..e81b715f872a 100644 --- a/share/man/man9/epoch.9 +++ b/share/man/man9/epoch.9 @@ -210,20 +210,6 @@ This function can sleep and is not optimized for performance. .Sh RETURN VALUES .Fn in_epoch curepoch will return 1 if curthread is in curepoch, 0 otherwise. -.Sh CAVEATS -One must be cautious when using -.Fn epoch_wait_preempt . -Threads are pinned during epoch sections, so if a thread in a section is then -preempted by a higher priority compute bound thread on that CPU, it can be -prevented from leaving the section indefinitely. -.Pp -Epochs are not a straight replacement for read locks. -Callers must use safe list and tailq traversal routines in an epoch (see ck_queue). -When modifying a list referenced from an epoch section safe removal -routines must be used and the caller can no longer modify a list entry -in place. -An item to be modified must be handled with copy on write -and frees must be deferred until after a grace period has elapsed. .Sh EXAMPLES Async free example: Thread 1: @@ -280,12 +266,6 @@ free would have to follow a call to The .Nm kernel programming interface is under development and is subject to change. -.El -.Sh HISTORY -The -.Nm -framework first appeared in -.Fx 11.0 . .Sh SEE ALSO .Xr locking 9 , .Xr mtx_pool 9 , @@ -295,3 +275,22 @@ framework first appeared in .Xr sleep 9 , .Xr sx 9 , .Xr timeout 9 +.Sh HISTORY +The +.Nm +framework first appeared in +.Fx 11.0 . +.Sh CAVEATS +One must be cautious when using +.Fn epoch_wait_preempt . +Threads are pinned during epoch sections, so if a thread in a section is then +preempted by a higher priority compute bound thread on that CPU, it can be +prevented from leaving the section indefinitely. +.Pp +Epochs are not a straight replacement for read locks. +Callers must use safe list and tailq traversal routines in an epoch (see ck_queue). +When modifying a list referenced from an epoch section safe removal +routines must be used and the caller can no longer modify a list entry +in place. +An item to be modified must be handled with copy on write +and frees must be deferred until after a grace period has elapsed. |