From: Ben Hutchings <bhutchings@solarflare.com>
To: David Decotigny <david.decotigny@google.com>
Cc: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Ian Campbell <ian.campbell@citrix.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Subject: Re: [PATCH net-next v1 0/9] forcedeth: stats & debug enhancements
Date: Wed, 9 Nov 2011 23:41:13 +0000 [thread overview]
Message-ID: <1320882073.2781.20.camel@bwh-desktop> (raw)
In-Reply-To: <cover.1320875577.git.david.decotigny@google.com>
On Wed, 2011-11-09 at 14:09 -0800, David Decotigny wrote:
> These changes implement the ndo_get_stats64 API and add a few more
> stats and debugging features for forcedeth. They also ensure that
> stats updates are correct in SMP systems, 32 or 64-bits.
>
> Regarding the "implement ndo_get_stats64() API" patch, I'm not sure
> I'm using the right way to protect the 64b stats. Ideally, I would
> like them to be non-blocking (u64_stats_sync.h), but as there are
> several sources for updates, I don't think I can do without locking or
> per-CPU stats.
The important thing is that the fast path remains fast, and I think
you've achieved that (due to patch 4/9). The data path doesn't have to
acquire the stats lock and it only has to use atomic operations in some
error cases.
> Would per-CPU stats be better here (note: I expect the
> contention on netdev_priv(dev)->stats_lock to be _VERY_ low)?
[...]
Only queue-less software devices should maintain per-CPU stats. For any
device with queues, servicing of each queue must already be serialised
and software stats can be maintained per-queue. In the single-queue
case this means per-device.
Ben.
--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
prev parent reply other threads:[~2011-11-09 23:41 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-09 22:09 [PATCH net-next v1 0/9] forcedeth: stats & debug enhancements David Decotigny
2011-11-09 22:09 ` [PATCH net-next v1 1/9] forcedeth: Add messages to indicate using MSI or MSI-X David Decotigny
2011-11-09 22:09 ` [PATCH net-next v1 2/9] forcedeth: allow to silence "TX timeout" debug messages David Decotigny
2011-11-09 22:09 ` [PATCH net-next v1 3/9] forcedeth: expose module parameters in /sys/module David Decotigny
2011-11-09 22:09 ` [PATCH net-next v1 4/9] forcedeth: stats for rx_packets based on hardware registers David Decotigny
2011-11-10 18:45 ` David Decotigny
2011-11-09 22:09 ` [PATCH net-next v1 5/9] forcedeth: implement ndo_get_stats64() API David Decotigny
2011-11-09 23:43 ` Ben Hutchings
2011-11-09 22:09 ` [PATCH net-next v1 6/9] forcedeth: account for dropped RX frames David Decotigny
2011-11-09 22:09 ` [PATCH net-next v1 7/9] forcedeth: new ethtool stat counter for TX timeouts David Decotigny
2011-11-09 22:09 ` [PATCH net-next v1 8/9] forcedeth: stats updated with a deferrable timer David Decotigny
2011-11-09 22:09 ` [PATCH net-next v1 9/9] forcedeth: whitespace/indentation fixes David Decotigny
2011-11-09 23:41 ` Ben Hutchings [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=1320882073.2781.20.camel@bwh-desktop \
--to=bhutchings@solarflare.com \
--cc=davem@davemloft.net \
--cc=david.decotigny@google.com \
--cc=eric.dumazet@gmail.com \
--cc=ian.campbell@citrix.com \
--cc=jeffrey.t.kirsher@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox