From: Peter Zijlstra <peterz@infradead.org>
To: john.stultz@linaro.org, tglx@linutronix.de
Cc: pawel.moll@arm.com, adrian.hunter@intel.com, mingo@kernel.org,
eranian@google.com, linux-kernel@vger.kernel.org,
acme@kernel.org, dsahern@gmail.com, fweisbec@gmail.com,
jolsa@redhat.com, namhyung@gmail.com, paulus@samba.org,
rostedt@goodmis.org, sonnyrao@chromium.org, ak@linux.intel.com,
vincent.weaver@maine.edu, peterz@infradead.org
Subject: [RFC][PATCH 3/4] time: Parametrize all tk_fast_mono users
Date: Thu, 19 Mar 2015 10:31:40 +0100 [thread overview]
Message-ID: <20150319093400.484279927@infradead.org> (raw)
In-Reply-To: <20150319093137.149794496@infradead.org>
[-- Attachment #1: peterz-fast-raw-3.patch --]
[-- Type: text/plain, Size: 2566 bytes --]
In preparation for more tk_fast instances, remove all hard-coded
tk_fast_mono references.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/time/timekeeping.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -364,18 +364,18 @@ static inline s64 timekeeping_get_ns(str
* 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(struc
* 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
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 ti
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);
}
/**
next prev parent reply other threads:[~2015-03-19 9:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-19 9:31 [RFC][PATCH 0/4] Another go at ktime_get_raw_fast_ns() Peter Zijlstra
2015-03-19 9:31 ` [RFC][PATCH 1/4] time: Rename timekeeper::tkr to timekeeper::tkr_mono Peter Zijlstra
2015-03-27 11:44 ` [tip:perf/timer] time: Rename timekeeper::tkr to timekeeper:: tkr_mono tip-bot for Peter Zijlstra
2015-03-19 9:31 ` [RFC][PATCH 2/4] time: Add timerkeeper::tkr_raw Peter Zijlstra
2015-03-27 11:44 ` [tip:perf/timer] " tip-bot for Peter Zijlstra
2015-03-19 9:31 ` Peter Zijlstra [this message]
2015-03-27 11:45 ` [tip:perf/timer] time: Parametrize all tk_fast_mono users tip-bot for Peter Zijlstra
2015-03-19 9:31 ` [RFC][PATCH 4/4] time: Introduce tk_fast_raw Peter Zijlstra
2015-03-27 11:45 ` [tip:perf/timer] " tip-bot for Peter Zijlstra
2015-03-24 15:20 ` [RFC][PATCH 0/4] Another go at ktime_get_raw_fast_ns() John Stultz
2015-03-24 15:48 ` Peter Zijlstra
2015-03-24 16:00 ` John Stultz
2015-03-24 21:02 ` John Stultz
2015-03-25 14:58 ` Peter Zijlstra
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