From: Thomas Gleixner <tglx@linutronix.de>
To: Kaiwan N Billimoria <kaiwan.billimoria@gmail.com>
Cc: Llillian@star-ark.net, agordeev@linux.ibm.com,
akpm@linux-foundation.org, alexander.shishkin@linux.intel.com,
anna-maria@linutronix.de, bigeasy@linutronix.de,
catalin.marinas@arm.com, chenhuacai@kernel.org,
francesco@valla.it, frederic@kernel.org,
guoweikang.kernel@gmail.com, jstultz@google.com,
kpsingh@kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, mark.rutland@arm.com,
maz@kernel.org, mingo@kernel.org, pmladek@suse.com,
rrangel@chromium.org, sboyd@kernel.org, urezki@gmail.com,
v-singh1@ti.com, will@kernel.org,
Kaiwan N Billimoria <kaiwan.billimoria@gmail.com>
Subject: Re: [RFC PATCH] time: introduce BOOT_TIME_TRACKER and minimal boot timestamp
Date: Tue, 02 Sep 2025 12:52:37 +0200 [thread overview]
Message-ID: <87a53d2kju.ffs@tglx> (raw)
In-Reply-To: <20250902070253.936687-1-kaiwan.billimoria@gmail.com>
On Tue, Sep 02 2025 at 12:32, Kaiwan N. Billimoria wrote:
> So, just confirming: here 1409443611 divided by 200 MHz gives us 7.047218055s
> since boot, and thus the actual timestamp here is that plus 0.000001s yes?
> (Over 7s here? yes, it's just that I haven't yet setup U-Boot properly for uSD
> card boot, thus am manually loading commands in U-Boot to boot up, that's all).
Looks about right.
> A question (perhaps very stupid): will the hwcnt - the output of the read() -
> be guaranteed to be (close to) the number of increments since processor
> power-up (or reset)? Meaning, it's simply a hardware feature and agnostic to
> what code the core was executing (ROM/BL/kernel), yes?
Under the assumption that nothing on the way resets the counter.
Thanks
tglx
next prev parent reply other threads:[~2025-09-02 13:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-23 4:40 [RFC PATCH] time: introduce BOOT_TIME_TRACKER and minimal boot timestamp vishnu singh
2025-08-23 22:53 ` Thomas Gleixner
2025-08-23 23:12 ` Thomas Gleixner
2025-09-01 4:05 ` Kaiwan N Billimoria
2025-09-01 5:57 ` Kaiwan N Billimoria
2025-09-02 7:02 ` [RFC PATCH] time: introduce BOOT_TIME_TRACKER and minimal boot timestamp Kaiwan N Billimoria
2025-09-02 10:52 ` Thomas Gleixner [this message]
2025-09-02 13:39 ` Kaiwan N Billimoria
2025-09-02 21:32 ` Thomas Gleixner
-- strict thread matches above, loose matches on Subject: below --
2025-08-23 4:19 vishnu singh
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