From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Eric Dumazet <edumazet@google.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Chris Mason <clm@fb.com>, Arjan van de Ven <arjan@infradead.org>,
rt@linutronix.de, Rik van Riel <riel@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
George Spelvin <linux@sciencehorizons.net>,
Len Brown <lenb@kernel.org>
Subject: [patch V2 16/20] tick/sched: Remove pointless empty function
Date: Fri, 17 Jun 2016 13:26:43 -0000 [thread overview]
Message-ID: <20160617131004.142603386@linutronix.de> (raw)
In-Reply-To: 20160617121134.417319325@linutronix.de
[-- Attachment #1: ticksched_Remove_pointless_empty_function.patch --]
[-- Type: text/plain, Size: 2021 bytes --]
This was a failed attempt to optimize the timer expiry in idle, which was
disabled and never revisited. Remove the cruft.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Mason <clm@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: rt@linutronix.de
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
---
kernel/time/tick-sched.c | 33 +--------------------------------
1 file changed, 1 insertion(+), 32 deletions(-)
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1092,35 +1092,6 @@ static void tick_nohz_switch_to_nohz(voi
tick_nohz_activate(ts, NOHZ_MODE_LOWRES);
}
-/*
- * When NOHZ is enabled and the tick is stopped, we need to kick the
- * tick timer from irq_enter() so that the jiffies update is kept
- * alive during long running softirqs. That's ugly as hell, but
- * correctness is key even if we need to fix the offending softirq in
- * the first place.
- *
- * Note, this is different to tick_nohz_restart. We just kick the
- * timer and do not touch the other magic bits which need to be done
- * when idle is left.
- */
-static void tick_nohz_kick_tick(struct tick_sched *ts, ktime_t now)
-{
-#if 0
- /* Switch back to 2.6.27 behaviour */
- ktime_t delta;
-
- /*
- * Do not touch the tick device, when the next expiry is either
- * already reached or less/equal than the tick period.
- */
- delta = ktime_sub(hrtimer_get_expires(&ts->sched_timer), now);
- if (delta.tv64 <= tick_period.tv64)
- return;
-
- tick_nohz_restart(ts, now);
-#endif
-}
-
static inline void tick_nohz_irq_enter(void)
{
struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
@@ -1131,10 +1102,8 @@ static inline void tick_nohz_irq_enter(v
now = ktime_get();
if (ts->idle_active)
tick_nohz_stop_idle(ts, now);
- if (ts->tick_stopped) {
+ if (ts->tick_stopped)
tick_nohz_update_jiffies(now);
- tick_nohz_kick_tick(ts, now);
- }
}
#else
next prev parent reply other threads:[~2016-06-17 13:28 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-17 13:26 [patch V2 00/20] timer: Refactor the timer wheel Thomas Gleixner
2016-06-17 13:26 ` [patch V2 01/20] timer: Make pinned a timer property Thomas Gleixner
2016-06-17 13:26 ` [patch V2 02/20] x86/apic/uv: Initialize timer as pinned Thomas Gleixner
2016-06-17 13:26 ` [patch V2 03/20] x86/mce: " Thomas Gleixner
2016-06-17 13:26 ` [patch V2 05/20] driver/net/ethernet/tile: " Thomas Gleixner
2016-06-21 18:14 ` Peter Zijlstra
2016-06-17 13:26 ` [patch V2 04/20] cpufreq/powernv: " Thomas Gleixner
2016-06-17 13:26 ` [patch V2 06/20] drivers/tty/metag_da: " Thomas Gleixner
2016-06-17 13:26 ` [patch V2 07/20] drivers/tty/mips_ejtag: " Thomas Gleixner
2016-06-17 13:26 ` [patch V2 08/20] net/ipv4/inet: Initialize timers " Thomas Gleixner
2016-06-17 13:26 ` [patch V2 09/20] timer: Remove mod_timer_pinned Thomas Gleixner
2016-06-17 13:26 ` [patch V2 10/20] hlist: Add hlist_is_singular_node() helper Thomas Gleixner
2016-06-17 13:26 ` [patch V2 11/20] timer: Give a few structs and members proper names Thomas Gleixner
2016-06-17 13:26 ` [patch V2 12/20] timer: Switch to a non cascading wheel Thomas Gleixner
2016-06-18 9:55 ` George Spelvin
2016-06-24 10:06 ` Thomas Gleixner
2016-06-17 13:26 ` [patch V2 13/20] timer: Remove slack leftovers Thomas Gleixner
2016-06-17 13:26 ` [patch V2 14/20] timer: Move __run_timers() function Thomas Gleixner
2016-06-17 13:26 ` [patch V2 15/20] timer: Optimize collect timers for NOHZ Thomas Gleixner
2016-06-17 13:26 ` Thomas Gleixner [this message]
2016-06-17 13:26 ` [patch V2 17/20] timer: Forward wheel clock whenever possible Thomas Gleixner
2016-06-17 13:26 ` [patch V2 18/20] timer: Only wake softirq if necessary Thomas Gleixner
2016-06-17 13:26 ` [patch V2 19/20] timer: Split out index calculation Thomas Gleixner
2016-06-17 13:26 ` [patch V2 20/20] timer: Optimization for same expiry time in mod_timer() Thomas Gleixner
2016-06-17 13:48 ` [patch V2 00/20] timer: Refactor the timer wheel Eric Dumazet
2016-06-17 13:57 ` Thomas Gleixner
2016-06-17 14:25 ` Eric Dumazet
2016-06-20 13:56 ` Thomas Gleixner
2016-06-20 14:46 ` Arjan van de Ven
2016-06-20 14:46 ` Thomas Gleixner
2016-06-20 14:49 ` Arjan van de Ven
2016-06-20 19:03 ` Rik van Riel
2016-06-21 2:48 ` Eric Dumazet
2016-06-17 14:26 ` Arjan van de Ven
2016-06-20 15:05 ` Paul E. McKenney
2016-06-20 15:13 ` Thomas Gleixner
2016-06-20 15:41 ` Paul E. McKenney
2016-06-22 7:37 ` Mike Galbraith
2016-06-22 8:44 ` Thomas Gleixner
2016-06-22 9:06 ` Mike Galbraith
2016-06-22 13:37 ` Mike Galbraith
2016-06-22 10:28 ` [LTP] " Cyril Hrubis
2016-06-23 8:27 ` Thomas Gleixner
2016-06-23 11:47 ` Cyril Hrubis
2016-06-23 13:58 ` George Spelvin
2016-06-23 14:10 ` Thomas Gleixner
2016-06-23 15:11 ` Cyril Hrubis
2016-06-23 15:21 ` Thomas Gleixner
2016-06-23 16:31 ` Cyril Hrubis
2016-06-26 19:00 ` Pavel Machek
2016-06-26 19:21 ` Arjan van de Ven
2016-06-26 20:02 ` Pavel Machek
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