All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ed W <lists@wildgooses.com>
To: johnstul@us.ibm.com, linux-kernel@vger.kernel.org
Subject: Improved TSC calculation
Date: Thu, 14 Apr 2011 12:19:54 +0100	[thread overview]
Message-ID: <4DA6D85A.8000800@wildgooses.com> (raw)

Hi, Thanks for the new stable TSC calculation commit
(08ec0c58fb8a05d3191d5cb6f5d6f81adb419798).

My situation is that I don't have a PM or HPET timer (x86 Alix board),
and my requirements are embedded type use, but with only intermittently
connected network/gps, so accurate timekeeping between reboots is
important.

I had been experimenting with extending the existing PIT timer routines
at boot, but I had the problem that it was taking 1s+ to get a very
stable calculation (which is undesirable for my requirements), however,
having spotted your commit it seems like a much more sensible solution.

Before I try and hack probably an (inadequate) solution myself, do you
have any thoughts on the best solution to extend your commit to non
PM/HEPT machine?  My initial thought was to repeatedly call
pit_calibrate_tsc() with an extended latch, looking for a stable
solution (ie refactor native_calibrate_tsc() ).  Is this workable?
Better ideas?

Thanks

Ed W

             reply	other threads:[~2011-04-14 11:19 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-14 11:19 Ed W [this message]
2011-04-14 18:20 ` Improved TSC calculation john stultz
2011-04-20 15:10   ` Ed W
2011-12-09 13:01   ` Ed W
2011-12-09 18:55     ` john stultz

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=4DA6D85A.8000800@wildgooses.com \
    --to=lists@wildgooses.com \
    --cc=johnstul@us.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.