svn commit: r335531 - head/share/man/man9

[Eitan Adler]

Author: eadler
Date: Fri Jun 22 06:04:22 2018
New Revision: 335531
URL: https://svnweb.freebsd.org/changeset/base/335531

Log:
  epoch.9: fix some style and speeling issues
  
  Reported by:	Yutaro Hayakawa <yhayakawa3720 at gmail.com> (spelling)
  Differential Revision: https://reviews.freebsd.org/D15961

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

Modified: head/share/man/man9/epoch.9
==============================================================================
--- head/share/man/man9/epoch.9	Fri Jun 22 04:54:51 2018	(r335530)
+++ head/share/man/man9/epoch.9	Fri Jun 22 06:04:22 2018	(r335531)
@@ -1,5 +1,5 @@
 .\"
-.\" Copyright (C) 2018 Matthew Macy <mmacy at FreeBSD.org>. 
+.\" Copyright (C) 2018 Matthew Macy <mmacy at FreeBSD.org>.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
@@ -65,15 +65,15 @@
 .Sh DESCRIPTION
 Epochs are used to guarantee liveness and immutability of data by
 deferring reclamation and mutation until a grace period has elapsed.
-Epochs do not have any lock ordering issues. Entering and leaving
-an epoch section will never block.
+Epochs do not have any lock ordering issues.
+Entering and leaving an epoch section will never block.
 .Pp
 Epochs are allocated with
 .Fn epoch_alloc
 and freed with
 .Fn epoch_free .
 The flags passed to epoch_alloc determine whether preemption is
-allowed during a section or not (the dafult), as specified by
+allowed during a section or not (the default), as specified by
 EPOCH_PREEMPT.
 Threads indicate the start of an epoch critical section by calling
 .Fn epoch_enter .
@@ -104,16 +104,17 @@ INVARIANTS can assert that a thread is in an epoch by 
 .Fn in_epoch .
 .Pp
 The epoch API currently does not support sleeping in epoch_preempt sections.
-A caller cannot do epoch_enter recursively on different preemptible epochs. A
-caller should never call
+A caller cannot do epoch_enter recursively on different preemptible epochs.
+A caller should never call
 .Fn epoch_wait
 in the middle of an epoch section as this will lead to a deadlock.
 .Pp
-Note that epochs are not a straight replacement for read locks. Callers
-must use safe list and tailq traversal routines in an epoch (see ck_queue).
+Note that 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
+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 RETURN VALUES
 .Fn in_epoch
@@ -123,11 +124,11 @@ 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. Thus the wait time for the waiter is
+prevented from leaving the section.
+Thus the wait time for the waiter is
 potentially unbounded.
 .Sh EXAMPLES
 Async free example:
-
 Thread 1:
 .Bd -literal
 int
@@ -164,7 +165,7 @@ void
 if_purgeaddrs(struct ifnet *ifp)
 {
 
-    /* .... */	
+    /* .... *
     IF_ADDR_WLOCK(ifp);
     CK_STAILQ_REMOVE(&ifp->if_addrhead, ifa, ifaddr, ifa_link);
     IF_ADDR_WUNLOCK(ifp);
@@ -172,10 +173,11 @@ if_purgeaddrs(struct ifnet *ifp)
 }
 .Ed
 .Pp
-Thread 1 traverses the ifaddr list in an epoch. Thread 2 unlinks
-with the corresponding epoch safe macro, marks as logically free,
-and then defers deletion. More general mutation or a synchronous
-free would have to follow a a call to
+Thread 1 traverses the ifaddr list in an epoch.
+Thread 2 unlinks with the corresponding epoch safe macro, marks as logically free,
+and then defers deletion.
+More general mutation or a synchronous
+free would have to follow a call to
 .Fn epoch_wait .
 .Sh ERRORS
 None.