From: "john stultz" <johnstul@us.ibm.com>
To: "John Richard Moser" <nigelenki@comcast.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: gettimeofday(), clock_gettime(), timer_gettime()
Date: Wed, 26 Jul 2006 09:08:46 -0700 [thread overview]
Message-ID: <1f1b08da0607260908u753684c5ocda8b361db65227b@mail.gmail.com> (raw)
In-Reply-To: <44C6D8CD.4040604@comcast.net>
On 7/25/06, John Richard Moser <nigelenki@comcast.net> wrote:
> I'm looking through a few things and noticing some complaints about time
> and performance. Briefly, the following things have come to my attention:
>
> - gettimeofday() is slow, or so they say, needing several milliseconds
> to execute.
No. At worse its several microseconds (PIT takes about 18us, and its terrible!).
More likely you'll see ~1us using ACPI PM or HPET or ~500-100ns
(depending on your system). With vsyscall it can get into the sub
100ns range.
thanks
-john
prev parent reply other threads:[~2006-07-26 16:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-26 2:51 John Richard Moser
2006-07-26 15:22 ` Andi Kleen
2006-07-26 16:15 ` John Richard Moser
2006-07-26 16:08 ` john stultz [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1f1b08da0607260908u753684c5ocda8b361db65227b@mail.gmail.com \
--to=johnstul@us.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=nigelenki@comcast.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®