diff options
Diffstat (limited to 'share/man/man9/spl.9')
| -rw-r--r-- | share/man/man9/spl.9 | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/share/man/man9/spl.9 b/share/man/man9/spl.9 index 798c96fd075..bdd8ad28394 100644 --- a/share/man/man9/spl.9 +++ b/share/man/man9/spl.9 @@ -1,4 +1,4 @@ -.\" $OpenBSD: spl.9,v 1.4 2000/07/07 09:08:25 ho Exp $ +.\" $OpenBSD: spl.9,v 1.5 2000/10/12 18:06:03 aaron Exp $ .\" $NetBSD: spl.9,v 1.1 1997/03/11 06:15:05 mikel Exp $ .\" .\" Copyright (c) 1997 Michael Long. @@ -78,9 +78,11 @@ at a higher priority level. A .Nm function exists for each distinct priority level which can exist in -the system. These macros and the corresponding priority levels are +the system. +These macros and the corresponding priority levels are used for various defined purposes, and may be divided into two main -types: hard and soft. Hard interrupts are generated by hardware +types: hard and soft. +Hard interrupts are generated by hardware devices, while soft interrupts are generated by callouts and called from the kernel's periodic timer interrupt service routine. .Pp @@ -88,29 +90,31 @@ In order of highest to lowest priority, the priority-raising macros are: .Bl -tag -width splsoftclockXX .It Fn splhigh -blocks all hard and soft interrupts. It is used for code that cannot -tolerate any interrupts, like hardware context switching code and -the +blocks all hard and soft interrupts. +It is used for code that cannot +tolerate any interrupts, like hardware context switching code and the .Xr ddb 4 in-kernel debugger. .It Fn spltty -blocks hard interrupts from serial interfaces. Code running at this -level may not access the tty subsystem. +blocks hard interrupts from serial interfaces. +Code running at this level may not access the tty subsystem. .It Fn splsched -blocks interrupts that may access scheduler data structures. Code -running at or above this level may not call +blocks interrupts that may access scheduler data structures. +Code running at or above this level may not call .Fn sleep , .Fn tsleep , or .Fn wakeup , nor may it post signals. .It Fn splclock -blocks the hardware clock interrupt. It is used by +blocks the hardware clock interrupt. +It is used by .Fn hardclock to update kernel and process times, and must be used by any other code that accesses time-related data. .It Fn splstatclock -blocks the hardware statistics clock interrupt. It is used by +blocks the hardware statistics clock interrupt. +It is used by .Fn statclock to update kernel profiling and other statistics, and must be used by any code that accesses that data. @@ -136,7 +140,8 @@ blocks soft network interrupts. blocks soft clock interrupts. .El .Pp -Two macros lower the system priority level. They are: +Two macros lower the system priority level. +They are: .Bl -tag -width spllowersoftclockXX .It Fn spllowersoftclock unblocks all interrupts but the soft clock interrupt. |