From: Richard Cochran <richardcochran@gmail.com>
To: Vladimir Oltean <olteanv@gmail.com>
Cc: min.li.xe@renesas.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 3/3] ptp: idt82p33: optimize _idt82p33_adjfine
Date: Thu, 5 Nov 2020 09:02:04 -0800 [thread overview]
Message-ID: <20201105170204.GA5258@hoboy.vegasvil.org> (raw)
In-Reply-To: <20201105003556.tpgvlh3ponyxzjjl@skbuf>
On Thu, Nov 05, 2020 at 02:35:56AM +0200, Vladimir Oltean wrote:
> On the other hand and with all due respect, saying that it may have been
> 'buggy on some archs back in the day' and then not bringing any evidence
> is a bit of a strange claim to make.
You're right. I made the effort to look back into the days of v3.0,
and the only thing I could find is that the 32 bit implementation of
div_s64 does extra operations and invokes an additional function call.
But the difference in performance, if any, is probably not very large.
> I am actively using div_s64 in drivers/net/dsa/sja1105/sja1105_ptp.c
> successfully on arm and arm64.
Yeah, I see div_s64 has found its way into the ntp code, too, so it
must be fine.
Thanks,
Richard
next prev parent reply other threads:[~2020-11-05 17:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-04 16:01 [PATCH net-next 1/3] ptp: idt82p33: add adjphase support min.li.xe
2020-11-04 16:01 ` [PATCH net-next 2/3] ptp: idt82p33: use i2c_master_send for bus write min.li.xe
2020-11-04 16:43 ` Richard Cochran
2020-11-04 16:01 ` [PATCH net-next 3/3] ptp: idt82p33: optimize _idt82p33_adjfine min.li.xe
2020-11-04 16:46 ` Richard Cochran
2020-11-05 0:35 ` Vladimir Oltean
2020-11-05 17:02 ` Richard Cochran [this message]
2020-11-04 16:42 ` [PATCH net-next 1/3] ptp: idt82p33: add adjphase support Richard Cochran
2020-11-04 21:56 ` Jakub Kicinski
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=20201105170204.GA5258@hoboy.vegasvil.org \
--to=richardcochran@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=min.li.xe@renesas.com \
--cc=netdev@vger.kernel.org \
--cc=olteanv@gmail.com \
/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;
as well as URLs for NNTP newsgroup(s).