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From: Torben Hohn <torbenh@gmx.de>
To: linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, johnstul@us.ibm.com, hch@infradead.org,
	yong.zhang0@gmail.com, Torben Hohn <torbenh@gmx.de>
Subject: [PATCH 11/18] ia64: switch do_timer() to xtime_update()
Date: Sat, 22 Jan 2011 00:06:57 +0100	[thread overview]
Message-ID: <1295651224-29823-12-git-send-email-torbenh@gmx.de> (raw)
In-Reply-To: <1295651224-29823-1-git-send-email-torbenh@gmx.de>

local_cpu_data->itm_next = new_itm;  does not need to be protected
by this lock. and xtime_update() takes the lock itself.

Signed-off-by: Torben Hohn <torbenh@gmx.de>
---
 arch/ia64/kernel/time.c |   19 +++++--------------
 arch/ia64/xen/time.c    |   13 +++++--------
 2 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 9702fa9..156ad80 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -190,19 +190,10 @@ timer_interrupt (int irq, void *dev_id)
 
 		new_itm += local_cpu_data->itm_delta;
 
-		if (smp_processor_id() == time_keeper_id) {
-			/*
-			 * Here we are in the timer irq handler. We have irqs locally
-			 * disabled, but we don't know if the timer_bh is running on
-			 * another CPU. We need to avoid to SMP race by acquiring the
-			 * xtime_lock.
-			 */
-			write_seqlock(&xtime_lock);
-			do_timer(1);
-			local_cpu_data->itm_next = new_itm;
-			write_sequnlock(&xtime_lock);
-		} else
-			local_cpu_data->itm_next = new_itm;
+		if (smp_processor_id() == time_keeper_id)
+			xtime_update(1);
+
+		local_cpu_data->itm_next = new_itm;
 
 		if (time_after(new_itm, ia64_get_itc()))
 			break;
@@ -222,7 +213,7 @@ skip_process_time_accounting:
 		 * comfort, we increase the safety margin by
 		 * intentionally dropping the next tick(s).  We do NOT
 		 * update itm.next because that would force us to call
-		 * do_timer() which in turn would let our clock run
+		 * xtime_update() which in turn would let our clock run
 		 * too fast (with the potentially devastating effect
 		 * of losing monotony of time).
 		 */
diff --git a/arch/ia64/xen/time.c b/arch/ia64/xen/time.c
index c1c5445..1f8244a 100644
--- a/arch/ia64/xen/time.c
+++ b/arch/ia64/xen/time.c
@@ -139,14 +139,11 @@ consider_steal_time(unsigned long new_itm)
 		run_posix_cpu_timers(p);
 		delta_itm += local_cpu_data->itm_delta * (stolen + blocked);
 
-		if (cpu == time_keeper_id) {
-			write_seqlock(&xtime_lock);
-			do_timer(stolen + blocked);
-			local_cpu_data->itm_next = delta_itm + new_itm;
-			write_sequnlock(&xtime_lock);
-		} else {
-			local_cpu_data->itm_next = delta_itm + new_itm;
-		}
+		if (cpu == time_keeper_id)
+			xtime_update(stolen + blocked);
+
+		local_cpu_data->itm_next = delta_itm + new_itm;
+
 		per_cpu(xen_stolen_time, cpu) += NS_PER_TICK * stolen;
 		per_cpu(xen_blocked_time, cpu) += NS_PER_TICK * blocked;
 	}
-- 
1.7.2.3


  parent reply	other threads:[~2011-01-22  0:15 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-21 23:06 make arch code use xtime_update() instead of do_timer() Torben Hohn
2011-01-21 23:06 ` [PATCH 01/18] move do_timer() from kernel/timer.c into kernel/time/timekeeping.c Torben Hohn
2011-01-22  9:45   ` Thomas Gleixner
2011-01-24 20:32   ` john stultz
2011-01-24 22:10     ` Thomas Gleixner
2011-01-24 22:21       ` Peter Zijlstra
2011-01-24 22:44         ` Thomas Gleixner
2011-01-25  9:08           ` Peter Zijlstra
2011-01-25 10:34             ` Peter Zijlstra
2011-01-25 16:51               ` Peter Zijlstra
2011-01-26  5:56                 ` Yong Zhang
2011-01-26  6:49                   ` Yong Zhang
2011-01-26 10:03                   ` Peter Zijlstra
2011-01-26 11:11                     ` Yong Zhang
2011-01-21 23:06 ` [PATCH 02/18] provide xtime_update() which does not require holding xtime_lock like do_timer() Torben Hohn
2011-01-22 10:36   ` Thomas Gleixner
2011-01-21 23:06 ` [PATCH 03/18] alpha: change do_timer() to xtime_update() Torben Hohn
2011-01-21 23:06 ` [PATCH 04/18] arm: switch from " Torben Hohn
2011-01-21 23:06 ` [PATCH 05/18] arm/mach-clps711x: switch " Torben Hohn
2011-01-21 23:06 ` [PATCH 06/18] blackfin: switch from " Torben Hohn
2011-01-21 23:06 ` [PATCH 07/18] cris/arch-v10: switch " Torben Hohn
2011-01-21 23:06 ` [PATCH 08/18] cris/arch-v32: " Torben Hohn
2011-01-21 23:06 ` [PATCH 09/18] frv: " Torben Hohn
2011-01-22 10:01   ` Thomas Gleixner
2011-01-24 12:51     ` torbenh
2011-01-24 13:09       ` Thomas Gleixner
2011-01-21 23:06 ` [PATCH 10/18] h8300: " Torben Hohn
2011-01-21 23:06 ` Torben Hohn [this message]
2011-01-21 23:06 ` [PATCH 12/18] m32r: switch from " Torben Hohn
2011-01-21 23:06 ` [PATCH 13/18] m68k: switch " Torben Hohn
2011-01-21 23:07 ` [PATCH 14/18] mn10300: switch do_timer() to xtimer_update() Torben Hohn
2011-01-21 23:07 ` [PATCH 15/18] parisc: switch do_timer() to xtime_update() Torben Hohn
2011-01-21 23:07 ` [PATCH 16/18] sparc: " Torben Hohn
2011-01-22  0:51   ` David Miller
2011-01-21 23:07 ` [PATCH 17/18] xtensa: " Torben Hohn
2011-01-21 23:07 ` [PATCH 18/18] make do_timer() and xtime_lock private to the timer code Torben Hohn
2011-01-22 10:14 ` make arch code use xtime_update() instead of do_timer() Thomas Gleixner

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