linux-kernel - [tip:perf/timer] time: Parametrize all tk_fast

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Message-ID: <tip-4498e7467e9e441c18ca12f1ca08460356e0508a@git.kernel.org>
Date:	Fri, 27 Mar 2015 04:45:15 -0700
From:	tip-bot for Peter Zijlstra <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	peterz@...radead.org, mingo@...nel.org, hpa@...or.com,
	tglx@...utronix.de, linux-kernel@...r.kernel.org,
	john.stultz@...aro.org
Subject: [tip:perf/timer] time: Parametrize all tk_fast_mono users

Commit-ID:  4498e7467e9e441c18ca12f1ca08460356e0508a
Gitweb:     http://git.kernel.org/tip/4498e7467e9e441c18ca12f1ca08460356e0508a
Author:     Peter Zijlstra <peterz@...radead.org>
AuthorDate: Thu, 19 Mar 2015 09:36:19 +0100
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Fri, 27 Mar 2015 09:45:08 +0100

time: Parametrize all tk_fast_mono users

In preparation for more tk_fast instances, remove all hard-coded
tk_fast_mono references.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Acked-by: John Stultz <john.stultz@...aro.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Link: http://lkml.kernel.org/r/20150319093400.484279927@infradead.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 kernel/time/timekeeping.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cbb612e..278373e 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -364,18 +364,18 @@ static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
  * slightly wrong timestamp (a few nanoseconds). See
  * @ktime_get_mono_fast_ns.
  */
-static void update_fast_timekeeper(struct tk_read_base *tkr)
+static void update_fast_timekeeper(struct tk_read_base *tkr, struct tk_fast *tkf)
 {
-	struct tk_read_base *base = tk_fast_mono.base;
+	struct tk_read_base *base = tkf->base;
 
 	/* Force readers off to base[1] */
-	raw_write_seqcount_latch(&tk_fast_mono.seq);
+	raw_write_seqcount_latch(&tkf->seq);
 
 	/* Update base[0] */
 	memcpy(base, tkr, sizeof(*base));
 
 	/* Force readers back to base[0] */
-	raw_write_seqcount_latch(&tk_fast_mono.seq);
+	raw_write_seqcount_latch(&tkf->seq);
 
 	/* Update base[1] */
 	memcpy(base + 1, base, sizeof(*base));
@@ -413,20 +413,25 @@ static void update_fast_timekeeper(struct tk_read_base *tkr)
  * of the following timestamps. Callers need to be aware of that and
  * deal with it.
  */
-u64 notrace ktime_get_mono_fast_ns(void)
+static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf)
 {
 	struct tk_read_base *tkr;
 	unsigned int seq;
 	u64 now;
 
 	do {
-		seq = raw_read_seqcount(&tk_fast_mono.seq);
-		tkr = tk_fast_mono.base + (seq & 0x01);
+		seq = raw_read_seqcount(&tkf->seq);
+		tkr = tkf->base + (seq & 0x01);
 		now = ktime_to_ns(tkr->base) + timekeeping_get_ns(tkr);
+	} while (read_seqcount_retry(&tkf->seq, seq));
 
-	} while (read_seqcount_retry(&tk_fast_mono.seq, seq));
 	return now;
 }
+
+u64 ktime_get_mono_fast_ns(void)
+{
+	return __ktime_get_fast_ns(&tk_fast_mono);
+}
 EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns);
 
 /* Suspend-time cycles value for halted fast timekeeper. */
@@ -455,7 +460,7 @@ static void halt_fast_timekeeper(struct timekeeper *tk)
 	memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy));
 	cycles_at_suspend = tkr->read(tkr->clock);
 	tkr_dummy.read = dummy_clock_read;
-	update_fast_timekeeper(&tkr_dummy);
+	update_fast_timekeeper(&tkr_dummy, &tk_fast_mono);
 }
 
 #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
@@ -586,7 +591,7 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
 		memcpy(&shadow_timekeeper, &tk_core.timekeeper,
 		       sizeof(tk_core.timekeeper));
 
-	update_fast_timekeeper(&tk->tkr_mono);
+	update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono);
 }
 
 /**
--
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