From f8090b56cadf2a8dd828ebd5b7e3bc95d72e7acb Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Sun, 28 Oct 2012 07:37:42 +0100 Subject: [PATCH] time.7: Add a subsection on timer slack Signed-off-by: Michael Kerrisk --- man7/time.7 | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/man7/time.7 b/man7/time.7 index 764228430..5d8fedc11 100644 --- a/man7/time.7 +++ b/man7/time.7 @@ -23,7 +23,7 @@ .\" 2008-06-24, mtk: added some details about where jiffies come into .\" play; added section on high-resolution timers. .\" -.TH TIME 7 2010-02-25 "Linux" "Linux Programmer's Manual" +.TH TIME 7 2012-10-28 "Linux" "Linux Programmer's Manual" .SH NAME time \- overview of time and timers .SH DESCRIPTION @@ -171,6 +171,18 @@ see .BR timerfd_create (2), and .BR timer_create (2). +.SS Timer Slack +Since Linux 2.6.28, it is possible to control the "timer slack" +value for a thread. +The timer slack is the length of time by +which the kernel may delay the wake-up of certain +system calls that block with a timeout. +Permitting this delay allows the kernel to coallesce wake-up events, +thus possibly reducing the number of system wake-ups and saving power. +For more details, see the description of +.B PR_SET_TIMERSLACK +in +.BR prctl (2). .SH "SEE ALSO" .ad l .nh