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From: Anton Blanchard <anton@samba•org>
To: benh@kernel•crashing.org, paulus@samba•org, johnstul@us•ibm.com,
	miltonm@bga•com
Cc: linuxppc-dev@lists•ozlabs.org
Subject: [PATCH 4/6] powerpc/time: Remove unnecessary sanity check of decrementer expiration
Date: Thu, 24 Nov 2011 17:07:20 +1100	[thread overview]
Message-ID: <20111124060847.366751627@samba.org> (raw)
In-Reply-To: 20111124060716.362614789@samba.org

The clockevents code uses max_delta_ns to avoid calling a
clockevent with too large a value.

Remove the redundant version of this in the timer_interrupt
code.

Signed-off-by: Anton Blanchard <anton@samba•org>
---

Index: linux-build/arch/powerpc/kernel/time.c
===================================================================
--- linux-build.orig/arch/powerpc/kernel/time.c	2011-11-17 10:12:28.891690395 +1100
+++ linux-build/arch/powerpc/kernel/time.c	2011-11-17 10:13:54.241143987 +1100
@@ -572,7 +572,6 @@ void timer_interrupt(struct pt_regs * re
 	struct pt_regs *old_regs;
 	struct decrementer_clock *decrementer =  &__get_cpu_var(decrementers);
 	struct clock_event_device *evt = &decrementer->event;
-	u64 now;
 
 	/* Ensure a positive value is written to the decrementer, or else
 	 * some CPUs will continue to take decrementer exceptions.
@@ -607,16 +606,9 @@ void timer_interrupt(struct pt_regs * re
 		get_lppaca()->int_dword.fields.decr_int = 0;
 #endif
 
-	now = get_tb_or_rtc();
-	if (now >= decrementer->next_tb) {
-		decrementer->next_tb = ~(u64)0;
-		if (evt->event_handler)
-			evt->event_handler(evt);
-	} else {
-		now = decrementer->next_tb - now;
-		if (now <= DECREMENTER_MAX)
-			set_dec((int)now);
-	}
+	decrementer->next_tb = ~(u64)0;
+	if (evt->event_handler)
+		evt->event_handler(evt);
 
 #ifdef CONFIG_PPC_ISERIES
 	if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())

  parent reply	other threads:[~2011-11-24  6:07 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-24  6:07 [PATCH 0/6] ppc time fixes Anton Blanchard
2011-11-24  6:07 ` [PATCH 1/6] powerpc/time: Handle wrapping of decrementer Anton Blanchard
2011-11-28 17:44   ` Scott Wood
2011-11-28 20:01     ` Benjamin Herrenschmidt
2011-11-24  6:07 ` [PATCH 2/6] powerpc/time: Use clockevents_calc_mult_shift Anton Blanchard
2011-11-24  6:25   ` Kumar Gala
2011-11-28 11:47     ` Anton Blanchard
2011-11-24  6:07 ` [PATCH 3/6] powerpc/time: Use clocksource_register_hz Anton Blanchard
2011-11-28 23:30   ` john stultz
2011-11-24  6:07 ` Anton Blanchard [this message]
2011-11-24  6:07 ` [PATCH 5/6] powerpc/time: Fix some style issues Anton Blanchard
2011-11-24  6:07 ` [PATCH 6/6] powerpc/time: Optimise decrementer_check_overflow Anton Blanchard

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