NAME¶
__round_jiffies - function to round jiffies to a full second
SYNOPSIS¶
unsigned
long __round_jiffies(unsigned long j,
int cpu);
ARGUMENTS¶
j
the time in (absolute) jiffies that should be
rounded
cpu
the processor number on which the timeout will
happen
DESCRIPTION¶
__round_jiffies rounds an absolute time 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.
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.
The exact rounding is skewed for each processor to avoid all processors firing
at the exact same time, which could lead to lock contention or spurious cache
line bouncing.
The return value is the rounded version of the
j parameter.
COPYRIGHT¶
