'\" t .\" Title: round_jiffies_relative .\" Author: [FIXME: author] [see http://docbook.sf.net/el/author] .\" Generator: DocBook XSL Stylesheets v1.79.1 .\" Date: January 2017 .\" Manual: Driver Basics .\" Source: Kernel Hackers Manual 4.8.15 .\" Language: English .\" .TH "ROUND_JIFFIES_RELATI" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "Driver Basics" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" round_jiffies_relative \- function to round jiffies to a full second .SH "SYNOPSIS" .HP \w'unsigned\ long\ round_jiffies_relative('u .BI "unsigned long round_jiffies_relative(unsigned\ long\ " "j" ");" .SH "ARGUMENTS" .PP \fIj\fR .RS 4 the time in (relative) jiffies that should be rounded .RE .SH "DESCRIPTION" .PP \fBround_jiffies_relative\fR rounds a time delta in the future (in jiffies) up or down to (approximately) full seconds\&. This is useful for timers for which the exact time they fire does not matter too much, as long as they fire approximately every X seconds\&. .PP By rounding these timers to whole seconds, all such timers will fire at the same time, rather than at various times spread out\&. The goal of this is to have the CPU wake up less, which saves power\&. .PP The return value is the rounded version of the \fIj\fR parameter\&. .SH "COPYRIGHT" .br