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Date: Mon, 17 Oct 2011 17:24:42 -0700
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From: Garrett Cooper <yanegomi@gmail.com>
To: Arnaud Lacombe <lacombar@gmail.com>
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Cc: Ed Schouten <ed@80386.nl>, FreeBSD Current <freebsd-current@freebsd.org>
Subject: Re: [PATCH] Prepend timestamp in msgbuf
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On Mon, Oct 17, 2011 at 5:18 PM, Arnaud Lacombe <lacombar@gmail.com> wrote:
> Hi,
>
> On Mon, Oct 17, 2011 at 6:22 PM, Ed Schouten <ed@80386.nl> wrote:
>> Ah, missed something.
>>
>>> + =A0 =A0 =A0 =A0 =A0 =A0 getnanouptime(&ts);
>>> + =A0 =A0 =A0 =A0 =A0 =A0 err =3D snprintf(buf, sizeof buf, "[%zd.%.6ld=
] ",
>>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ts.tv_sec, ts.tv_nsec / 1000);
>>
>> It seems we also have a getmicrouptime(), which returns a struct
>> timeval.
> fixed.
>
>> Also a more general question: is it actually safe to call
>> getnanouptime() here? This code gets executed from an arbitrary context,
>> right?
>>
> right, but getmicrouptime() is not doing much magic. Just reading a
> cached value, do an arithmetic conversion. I do not really see any
> unsafe part.

Based on glancing around other areas of the kernel, I'd assume that
using this KPI as-is is fine because I don't see any locking employed
elsewhere...
-Garrett