Commit c7986acb authored Feb 22, 2009 by Ingo Molnar

time: ntp: micro-optimize ntp_update_offset()



Impact: cleanup, no functionality changed

The time_reftime update in ntp_update_offset() to xtime.tv_sec
is a convoluted way of saying that we want to freeze the frequency
and want the 'secs' delta to be 0. Also make this branch unlikely.

This shaves off 8 bytes from the code size:

   text	   data	    bss	    dec	    hex	filename
   2504	    114	    136	   2754	    ac2	ntp.o.before
   2496	    114	    136	   2746	    aba	ntp.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 478b7aab

kernel/time/ntp.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -141,10 +141,10 @@ static void ntp_update_offset(long offset)
		* Select how the frequency is to be controlled
		* and in which mode (PLL or FLL).
		*/
		if (time_status & STA_FREQHOLD \|\| time_reftime == 0)
		time_reftime = xtime.tv_sec;

		secs = xtime.tv_sec - time_reftime;
		if (unlikely(time_status & STA_FREQHOLD \|\| time_reftime == 0))
		secs = 0;

		time_reftime = xtime.tv_sec;

		offset64 = offset;