From: David Miller <davem@davemloft.net>
To: fenghua.yu@intel.com
Cc: michael.chan@broadcom.com, netdev@vger.kernel.org,
tglx@linutronix.de, luto@kernel.org, peterz@infradead.org,
tony.luck@intel.com, David.Laight@ACULAB.COM,
ravi.v.shankar@intel.com
Subject: Re: [PATCH] drivers/net/b44: Change to non-atomic bit operations
Date: Tue, 24 Dec 2019 16:18:26 -0800 (PST) [thread overview]
Message-ID: <20191224.161826.37676943451935844.davem@davemloft.net> (raw)
In-Reply-To: <1576884551-9518-1-git-send-email-fenghua.yu@intel.com>
From: Fenghua Yu <fenghua.yu@intel.com>
Date: Fri, 20 Dec 2019 15:29:11 -0800
> On x86, accessing data across two cache lines in one atomic bit
> operation (aka split lock) can take over 1000 cycles.
This happens during configuration of WOL, nobody cares that the atomic
operations done in this function take 1000 cycles each.
I'm not applying this patch. It is gratuitous, and the commit message
talks about "performance" considuations (cycle counts) that completely
don't matter here.
If you are merely just arbitrarily trying to remove locked atomic
operations across the tree for it's own sake, then you should be
completely honest about that in your commit message.
next prev parent reply other threads:[~2019-12-25 0:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-20 23:29 [PATCH] drivers/net/b44: Change to non-atomic bit operations Fenghua Yu
2019-12-25 0:18 ` David Miller [this message]
2019-12-25 1:10 ` Fenghua Yu
2019-12-25 2:23 ` David Miller
2020-01-02 21:27 ` [Patch v2] drivers/net/b44: Change to non-atomic bit operations on pwol_mask Luck, Tony
2020-01-05 22:22 ` David Miller
2019-12-25 20:24 ` [PATCH] drivers/net/b44: Change to non-atomic bit operations Stephen Hemminger
2020-01-02 18:22 ` Luck, Tony
2020-01-03 8:47 ` David Laight
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=20191224.161826.37676943451935844.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=David.Laight@ACULAB.COM \
--cc=fenghua.yu@intel.com \
--cc=luto@kernel.org \
--cc=michael.chan@broadcom.com \
--cc=netdev@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=ravi.v.shankar@intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.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).