powerpc: Eliminate unused do_gtod variable (3cc69878) · Commits · 戴 / test

arch/powerpc/include/asm/time.h

+0 −20

Original line number	Diff line number	Diff line
		@@ -48,26 +48,6 @@ extern unsigned long ppc_proc_freq;
		extern unsigned long ppc_tb_freq;
		#define DEFAULT_TB_FREQ 125000000UL

		/*
		* By putting all of this stuff into a single struct we
		* reduce the number of cache lines touched by do_gettimeofday.
		* Both by collecting all of the data in one cache line and
		* by touching only one TOC entry on ppc64.
		*/
		struct gettimeofday_vars {
		u64 tb_to_xs;
		u64 stamp_xsec;
		u64 tb_orig_stamp;
		};

		struct gettimeofday_struct {
		unsigned long tb_ticks_per_sec;
		struct gettimeofday_vars vars[2];
		struct gettimeofday_vars * volatile varp;
		unsigned var_idx;
		unsigned tb_to_us;
		};

		struct div_result {
		u64 result_high;
		u64 result_low;

arch/powerpc/kernel/time.c

+0 −35

Original line number	Diff line number	Diff line
		@@ -164,8 +164,6 @@ static u64 tb_to_ns_scale __read_mostly;
		static unsigned tb_to_ns_shift __read_mostly;
		static unsigned long boot_tb __read_mostly;

		static struct gettimeofday_struct do_gtod;

		extern struct timezone sys_tz;
		static long timezone_offset;

		@@ -415,31 +413,9 @@ void udelay(unsigned long usecs)
		}
		EXPORT_SYMBOL(udelay);


		/*
		* There are two copies of tb_to_xs and stamp_xsec so that no
		* lock is needed to access and use these values in
		* do_gettimeofday. We alternate the copies and as long as a
		* reasonable time elapses between changes, there will never
		* be inconsistent values. ntpd has a minimum of one minute
		* between updates.
		*/
		static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
		u64 new_tb_to_xs)
		{
		unsigned temp_idx;
		struct gettimeofday_vars *temp_varp;

		temp_idx = (do_gtod.var_idx == 0);
		temp_varp = &do_gtod.vars[temp_idx];

		temp_varp->tb_to_xs = new_tb_to_xs;
		temp_varp->tb_orig_stamp = new_tb_stamp;
		temp_varp->stamp_xsec = new_stamp_xsec;
		smp_mb();
		do_gtod.varp = temp_varp;
		do_gtod.var_idx = temp_idx;

		/*
		* tb_update_count is used to allow the userspace gettimeofday code
		* to assure itself that it sees a consistent view of the tb_to_xs and
		@@ -515,9 +491,7 @@ static int __init iSeries_tb_recal(void)
		tb_ticks_per_sec = new_tb_ticks_per_sec;
		calc_cputime_factors();
		div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres );
		do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
		tb_to_xs = divres.result_low;
		do_gtod.varp->tb_to_xs = tb_to_xs;
		vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
		vdso_data->tb_to_xs = tb_to_xs;
		}
		@@ -989,15 +963,6 @@ void __init time_init(void)
		sys_tz.tz_dsttime = 0;
		}

		do_gtod.varp = &do_gtod.vars[0];
		do_gtod.var_idx = 0;
		do_gtod.varp->tb_orig_stamp = tb_last_jiffy;
		__get_cpu_var(last_jiffy) = tb_last_jiffy;
		do_gtod.varp->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC;
		do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
		do_gtod.varp->tb_to_xs = tb_to_xs;
		do_gtod.tb_to_us = tb_to_us;

		vdso_data->tb_orig_stamp = tb_last_jiffy;
		vdso_data->tb_update_count = 0;
		vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;

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