From: David Vrabel <david.vrabel@citrix.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Tim Deegan <tim@xen.org>, Keir Fraser <keir@xen.org>,
Jan Beulich <JBeulich@suse.com>,
Xen-devel <xen-devel@lists.xen.org>
Subject: Re: [PATCH v2 2/5] x86/time: Always count s_time from Xen boot
Date: Mon, 3 Mar 2014 10:59:17 +0000 [thread overview]
Message-ID: <53146085.6060400@citrix.com> (raw)
In-Reply-To: <1393613824-13230-3-git-send-email-andrew.cooper3@citrix.com>
On 28/02/14 18:57, Andrew Cooper wrote:
> From: Tim Deegan <tim@xen.org>
>
> In the early-boot clock, before the calibration routines kick in,
> count time from Xen boot rather than from when the BSP's TSC was 0.
>
> Signed-off-by: Tim Deegan <tim@xen.org>
>
> Stash the timestamp in head.S as a good approximation of when we actually
> started, rather than measuing "time since we ran early_time_init()"
Is this difference/accuracy interesting? It seems more obvious to me to
just read the TSC in early_time_init().
David
next prev parent reply other threads:[~2014-03-03 10:59 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-28 18:56 [RFC PATCH v2 0/5] Improvements to console timestamps Andrew Cooper
2014-02-28 18:57 ` [PATCH v2 1/5] x86/time: Avoid redundant this_cpu() Andrew Cooper
2014-02-28 18:57 ` [PATCH v2 2/5] x86/time: Always count s_time from Xen boot Andrew Cooper
2014-03-03 10:59 ` David Vrabel [this message]
2014-03-06 16:01 ` [PATCH v3] " Tim Deegan
2014-03-06 16:15 ` Jan Beulich
2014-03-06 16:18 ` Andrew Cooper
2014-02-28 18:57 ` [PATCH v2 3/5] x86/time: Initialise time earlier during start_secondary() Andrew Cooper
2014-03-04 9:02 ` Jan Beulich
2014-03-04 10:40 ` Andrew Cooper
2014-02-28 18:57 ` [PATCH v2 4/5] [RFC] xen/console: Provide timestamps as an offset since boot Andrew Cooper
2014-03-03 10:53 ` David Vrabel
2014-02-28 18:57 ` [PATCH v2 5/5] [RFC] Traditional console timestamps including milliseconds Andrew Cooper
2014-03-01 4:06 ` Julien Grall
2014-03-03 10:35 ` Andrew Cooper
2014-03-04 9:14 ` Jan Beulich
2014-03-04 10:30 ` Andrew Cooper
2014-03-04 20:51 ` Don Slutz
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