From 3171a0305d62e6627a24bff35af4f997e4988a80 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Fri, 29 Sep 2006 02:00:32 -0700 Subject: [PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem) Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390 timer interrupt handler with this change. Currently update_times() calculates ticks by "jiffies - wall_jiffies", but callers of do_timer() should know how many ticks to update. Passing ticks get rid of this redundant calculation. Also there are another redundancy pointed out by Martin Schwidefsky. This cleanup make a barrier added by 5aee405c662ca644980c184774277fc6d0769a84 needless. So this patch removes it. As a bonus, this cleanup make wall_jiffies can be removed easily, since now wall_jiffies is always synced with jiffies. (This patch does not really remove wall_jiffies. It would be another cleanup patch) Signed-off-by: Atsushi Nemoto Cc: Martin Schwidefsky Cc: "Eric W. Biederman" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: john stultz Cc: Andi Kleen Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Richard Henderson Cc: Ivan Kokshaysky Acked-by: Russell King Cc: Ian Molton Cc: Mikael Starvik Acked-by: David Howells Cc: Yoshinori Sato Cc: Hirokazu Takata Acked-by: Ralf Baechle Cc: Kyle McMartin Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Paul Mundt Cc: Kazumoto Kojima Cc: Richard Curnow Cc: William Lee Irwin III Cc: "David S. Miller" Cc: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Cc: Miles Bader Cc: Chris Zankel Acked-by: "Luck, Tony" Cc: Geert Uytterhoeven Cc: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/kernel/time.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'arch/s390/kernel/time.c') diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index 1981c6199fa..abab42e9f5f 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -166,7 +166,7 @@ EXPORT_SYMBOL(do_settimeofday); void account_ticks(struct pt_regs *regs) { __u64 tmp; - __u32 ticks, xticks; + __u32 ticks; /* Calculate how many ticks have passed. */ if (S390_lowcore.int_clock < S390_lowcore.jiffy_timer) { @@ -204,6 +204,7 @@ void account_ticks(struct pt_regs *regs) */ write_seqlock(&xtime_lock); if (S390_lowcore.jiffy_timer > xtime_cc) { + __u32 xticks; tmp = S390_lowcore.jiffy_timer - xtime_cc; if (tmp >= 2*CLK_TICKS_PER_JIFFY) { xticks = __div(tmp, CLK_TICKS_PER_JIFFY); @@ -212,13 +213,11 @@ void account_ticks(struct pt_regs *regs) xticks = 1; xtime_cc += CLK_TICKS_PER_JIFFY; } - while (xticks--) - do_timer(regs); + do_timer(xticks); } write_sequnlock(&xtime_lock); #else - for (xticks = ticks; xticks > 0; xticks--) - do_timer(regs); + do_timer(ticks); #endif #ifdef CONFIG_VIRT_CPU_ACCOUNTING -- cgit v1.2.3