From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
John Stultz <john.stultz@linaro.org>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [patch 54/55] timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC[_RAW]
Date: Mon, 14 Jul 2014 12:39:26 +0000 (UTC) [thread overview]
Message-ID: <1154261133.13906.1405341566164.JavaMail.zimbra@efficios.com> (raw)
In-Reply-To: <20140714094750.GO9918@twins.programming.kicks-ass.net>
----- Original Message -----
> From: "Peter Zijlstra" <peterz@infradead.org>
> To: "Thomas Gleixner" <tglx@linutronix.de>
> Cc: "LKML" <linux-kernel@vger.kernel.org>, "John Stultz" <john.stultz@linaro.org>, "Steven Rostedt"
> <rostedt@goodmis.org>, "Mathieu Desnoyers" <mathieu.desnoyers@efficios.com>
> Sent: Monday, July 14, 2014 5:47:50 AM
> Subject: Re: [patch 54/55] timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC[_RAW]
>
> On Fri, Jul 11, 2014 at 01:45:19PM -0000, Thomas Gleixner wrote:
> > +static struct tk_fast tk_fast_raw ____cacheline_aligned;
> > +static struct tk_fast tk_fast_mono ____cacheline_aligned;
>
> Question to the 'trace maniacs'; why do you lot need access to mono_raw?
>
> I would much prefer to limit choice here.
For LTTng, which I guess qualifies as bring part of the aforementioned
trace maniacs group, we only need the "tk_fast_mono" clock. We don't
need mono_raw.
We can then correlate with user-space traces by using tk_fast_mono in
kernel-space and using CLOCK_MONOTONIC in userspace.
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2014-07-14 12:39 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-11 13:43 [patch 00/55] timekeeping: 2038, optimizations, NMI safe accessors Thomas Gleixner
2014-07-11 13:43 ` [patch 01/55] tile: Convert VDSO timekeeping to the precise mechanism Thomas Gleixner
2014-07-18 2:32 ` Chris Metcalf
2014-07-11 13:44 ` [patch 02/55] timekeeping: Simplify arch_gettimeoffset() Thomas Gleixner
2014-07-11 14:10 ` Geert Uytterhoeven
2014-07-11 13:44 ` [patch 03/55] hrtimer: Cleanup hrtimer accessors to the timekepeing state Thomas Gleixner
2014-07-11 13:44 ` [patch 04/55] ktime: Kill non-scalar ktime_t implementation for 2038 Thomas Gleixner
2014-07-11 13:44 ` [patch 05/55] ktime: Sanitize ktime_to_us/ms conversion Thomas Gleixner
2014-07-11 13:44 ` [patch 06/55] ktime: Change ktime_set() to take 64bit seconds value Thomas Gleixner
2014-07-11 13:44 ` [patch 07/55] time64: Add time64.h header and define struct timespec64 Thomas Gleixner
2014-07-11 18:41 ` Richard Cochran
2014-07-11 13:44 ` [patch 08/55] time: More core infrastructure for timespec64 Thomas Gleixner
2014-07-11 13:44 ` [patch 09/55] timekeeping: Convert timekeeping core to use timespec64s Thomas Gleixner
2014-07-11 13:44 ` [patch 10/55] time: Consolidate the time accessor prototypes Thomas Gleixner
2014-07-11 13:44 ` [patch 11/55] timekeeping: Provide timespec64 based interfaces Thomas Gleixner
2014-07-11 13:44 ` [patch 12/55] timekeeper: Move tk_xtime to core code Thomas Gleixner
2014-07-11 13:44 ` [patch 13/55] timekeeping: Cache optimize struct timekeeper Thomas Gleixner
2014-07-11 13:44 ` [patch 14/55] timekeeping: Provide internal ktime_t based data Thomas Gleixner
2014-07-16 3:29 ` John Stultz
2014-07-16 7:00 ` Thomas Gleixner
2014-07-16 7:12 ` Thomas Gleixner
2014-07-16 7:20 ` Peter Zijlstra
2014-07-11 13:44 ` [patch 15/55] timekeeping: Use ktime_t based data for ktime_get() Thomas Gleixner
2014-07-11 13:44 ` [patch 16/55] timekeeping: Provide ktime_get_with_offset() Thomas Gleixner
2014-07-11 13:44 ` [patch 17/55] timekeeping: Use ktime_t based data for ktime_get_real() Thomas Gleixner
2014-07-11 13:44 ` [patch 18/55] timekeeping; Use ktime_t based data for ktime_get_boottime() Thomas Gleixner
2014-07-11 13:44 ` [patch 19/55] timekeeping: Use ktime_t based data for ktime_get_clocktai() Thomas Gleixner
2014-07-11 13:44 ` [patch 20/55] timekeeping: Use ktime_t data for ktime_get_update_offsets_now() Thomas Gleixner
2014-07-11 13:44 ` [patch 21/55] timekeeping; Use ktime based data for ktime_get_update_offsets_tick() Thomas Gleixner
2014-07-11 13:44 ` [patch 22/55] timekeeping: Provide ktime_mono_to_any() Thomas Gleixner
2014-07-11 13:44 ` [patch 23/55] timerfd: Use ktime_mono_to_real() Thomas Gleixner
2014-07-11 13:44 ` [patch 24/55] input: evdev: " Thomas Gleixner
2014-07-11 13:44 ` [patch 25/55] drm: " Thomas Gleixner
2014-07-11 13:44 ` [patch 26/55] timekeeping: Remove ktime_get_monotonic_offset() Thomas Gleixner
2014-07-11 13:44 ` [patch 27/55] timekeeping: Provide ktime_get[*]_ns() helpers Thomas Gleixner
2014-07-11 13:44 ` [patch 28/55] time-export-nsecs-to-jiffies.patch Thomas Gleixner
2014-07-11 13:44 ` [patch 29/55] sched: Make task->real_start_time nanoseconds based Thomas Gleixner
2014-07-11 13:44 ` [patch 30/55] sched: Make task->start_time " Thomas Gleixner
2014-07-11 13:44 ` [patch 31/55] delayacct: Make accounting nanosecond based Thomas Gleixner
2014-07-11 13:44 ` [patch 32/55] delayacct: Remove braindamaged type conversions Thomas Gleixner
2014-07-11 13:44 ` [patch 33/55] powerpc: cell: Use ktime_get_ns() Thomas Gleixner
2014-07-11 17:02 ` Arnd Bergmann
2014-07-11 13:44 ` [patch 34/55] connector: " Thomas Gleixner
2014-07-11 13:44 ` [patch 35/55] mfd: cros_ec_spi: " Thomas Gleixner
2014-07-11 14:52 ` Lee Jones
2014-07-12 19:40 ` Thomas Gleixner
2014-07-14 7:07 ` Lee Jones
2014-07-11 13:44 ` [patch 36/55] misc: ioc4: " Thomas Gleixner
2014-07-11 17:03 ` Arnd Bergmann
2014-07-12 0:26 ` Greg Kroah-Hartman
2014-07-11 13:44 ` [patch 37/55] net: mlx5: " Thomas Gleixner
2014-07-11 13:44 ` [patch 38/55] fs: lockd: " Thomas Gleixner
2014-07-11 14:04 ` Trond Myklebust
2014-07-11 13:44 ` [patch 39/55] hwmon: ibmaem: " Thomas Gleixner
2014-07-11 13:44 ` [patch 40/55] iio: Use ktime_get_real_ns() Thomas Gleixner
2014-07-13 9:21 ` Jonathan Cameron
2014-07-11 13:44 ` [patch 41/55] arm: bL_switcher:k " Thomas Gleixner
2014-07-11 13:45 ` [patch 42/55] x86: kvm: Use ktime_get_boot_ns() Thomas Gleixner
2014-07-11 13:45 ` [patch 43/55] x86: kvm: Make kvm_get_time_and_clockread() nanoseconds based Thomas Gleixner
2014-07-11 13:45 ` [patch 44/55] timekeeping: Remove monotonic_to_bootbased Thomas Gleixner
2014-07-11 13:45 ` [patch 45/55] timekeeping: Use ktime_get_boottime() for get_monotonic_boottime() Thomas Gleixner
2014-07-11 13:45 ` [patch 46/55] timekeeping: Provide ktime_get_raw() Thomas Gleixner
2014-07-11 13:45 ` [patch 47/55] hangcheck-timer: Use ktime_get_raw_ns() Thomas Gleixner
2014-07-11 17:03 ` Arnd Bergmann
2014-07-12 0:27 ` Greg Kroah-Hartman
2014-07-11 13:45 ` [patch 48/55] drm: i915: Use nsec based interfaces Thomas Gleixner
2014-07-14 9:21 ` Daniel Vetter
2014-07-11 13:45 ` [patch 49/55] drm: vmwgfx: " Thomas Gleixner
2014-07-11 13:45 ` [patch 50/55] wireless: ath9k: Get rid of timespec conversions Thomas Gleixner
2014-07-11 13:45 ` [patch 51/55] clocksource: Make delta calculation a function Thomas Gleixner
2014-07-14 8:31 ` Peter Zijlstra
2014-07-16 3:50 ` John Stultz
2014-07-16 6:58 ` Thomas Gleixner
2014-07-11 13:45 ` [patch 52/55] clocksource: Move cycle_last validation to core code Thomas Gleixner
2014-07-11 13:45 ` [patch 53/55] seqcount: Provide raw_read_seqcount() Thomas Gleixner
2014-07-11 13:45 ` [patch 54/55] timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC[_RAW] Thomas Gleixner
2014-07-11 20:04 ` Mathieu Desnoyers
2014-07-12 8:11 ` Thomas Gleixner
2014-07-12 13:59 ` Mathieu Desnoyers
2014-07-12 19:31 ` Thomas Gleixner
2014-07-12 14:53 ` Mathieu Desnoyers
2014-07-12 19:28 ` Thomas Gleixner
2014-07-12 20:04 ` Thomas Gleixner
2014-07-12 20:33 ` Mathieu Desnoyers
2014-07-14 8:37 ` Peter Zijlstra
2014-07-14 9:04 ` Thomas Gleixner
2014-07-14 9:45 ` Peter Zijlstra
2014-07-14 9:47 ` Peter Zijlstra
2014-07-14 12:39 ` Mathieu Desnoyers [this message]
2014-07-14 14:15 ` Thomas Gleixner
2014-07-11 13:45 ` [patch 55/55] ftrace: Provide trace clocks mono and mono_raw Thomas Gleixner
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