Re: [patch, v2.6.22-rc6] sys_time() speedup

From: Mark Lord
Date: Mon Jun 25 2007 - 20:23:00 EST


Ingo Molnar wrote:
Subject: [patch] sys_time() speedup
From: Ingo Molnar <mingo@xxxxxxx>

improve performance of sys_time(). sys_time() returns time in seconds, but it does so by calling do_gettimeofday() and then returning the tv_sec portion of the GTOD time. But the data structure "xtime", which is updated by every timer/scheduler tick, already offers HZ granularity time.

How well synchronized is xtime with real-time ?

Programs invoking sys_time() do expect it to be as accurate
as gettimeofday(), even if only at 1-second boundaries.

Cheers
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