From: Ben Hutchings <bhutchings@solarflare.com>
To: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
Stephen Hemminger <shemminger@vyatta.com>
Subject: Re: [RFT PATCH 3/9] net: ethtool: break association of ETH_FLAG_* with NETIF_F_*
Date: Mon, 20 Jun 2011 21:11:21 +0100 [thread overview]
Message-ID: <1308600681.2701.159.camel@bwh-desktop> (raw)
In-Reply-To: <51d2fd4cf6855c2285ca9bcd8d267abedcbc599c.1308596963.git.mirq-linux@rere.qmqm.pl>
On Mon, 2011-06-20 at 21:14 +0200, Michał Mirosław wrote:
> This is the only place where NETIF_F_* feature flags are exposed
> to userspace.
Except sysfs.
> After this patch feature flags may be changed/reordered freely.
[...]
Really, what do you think was the point of exposing features through
sysfs if they are going to be changed?
Oh, but they have been changed already:
v2.5.70
net-sysfs added
v2.6.15
+#define NETIF_F_UFO 8192 /* Can offload UDP Large Send*/
v2.6.18
-#define NETIF_F_TSO 2048 /* Can offload TCP/IP segmentation */
-#define NETIF_F_UFO 8192 /* Can offload UDP Large Send*/
+#define NETIF_F_GSO 2048 /* Enable software GSO. */
+#define NETIF_F_GSO_SHIFT 16
+#define NETIF_F_TSO (SKB_GSO_TCPV4 << NETIF_F_GSO_SHIFT)
+#define NETIF_F_UFO (SKB_GSO_UDP << NETIF_F_GSO_SHIFT)
+#define NETIF_F_GSO_ROBUST (SKB_GSO_DODGY << NETIF_F_GSO_SHIFT)
+#define NETIF_F_TSO_ECN (SKB_GSO_TCP_ECN << NETIF_F_GSO_SHIFT)
+#define NETIF_F_TSO6 (SKB_GSO_TCPV6 << NETIF_F_GSO_SHIFT)
v2.6.23
+#define NETIF_F_IPV6_CSUM 16 /* Can checksum TCP/UDP over IPV6 */
+#define NETIF_F_MULTI_QUEUE 16384 /* Has multiple TX/RX queues */
v2.6.24
+#define NETIF_F_NETNS_LOCAL 8192 /* Does not change network namespaces */
v2.6.27
-#define NETIF_F_MULTI_QUEUE 16384 /* Has multiple TX/RX queues */
v2.6.29
+#define NETIF_F_GRO 16384 /* Generic receive offload */
(I've omitted changes that use previously unused bits.)
If we're going to keep changing features (maybe even more often) then we
have to do something about this sysfs attribute. Maybe get rid of it
(as it seems not to be widely used, thankfully). Maybe fix it to use
the same feature values as today, but no new features. But certainly
don't pretend that feature flags are not exposed.
Ben.
--
Ben Hutchings, Senior Software 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.
next prev parent reply other threads:[~2011-06-20 20:11 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-20 19:14 [RFT PATCH 0/9] Cleanup and extension of netdev features Michał Mirosław
2011-06-20 19:14 ` [RFT PATCH 2/9] net: remove legacy ethtool ops Michał Mirosław
2011-06-20 19:14 ` [RFT PATCH 3/9] net: ethtool: break association of ETH_FLAG_* with NETIF_F_* Michał Mirosław
2011-06-20 20:11 ` Ben Hutchings [this message]
2011-06-20 20:27 ` David Miller
2011-06-20 20:51 ` Stephen Hemminger
2011-06-20 20:52 ` David Miller
2011-06-20 21:30 ` Ben Hutchings
2011-06-20 19:14 ` [RFT PATCH 5/9] net: Define enum for net device features Michał Mirosław
2011-06-20 19:14 ` [RFT PATCH 4/9] net: introduce and use netdev_features_t for device features sets Michał Mirosław
2011-06-20 21:01 ` Ben Hutchings
2011-06-20 19:14 ` [RFT PATCH 9/9] net: move NOCACHE_COPY checks to netdev_fix_features() Michał Mirosław
2011-06-20 19:14 ` [RFT PATCH 7/9] ethtool: prepare for larger netdev_features_t type Michał Mirosław
2011-06-20 21:16 ` Ben Hutchings
2011-06-23 17:50 ` Mahesh Bandewar
2011-06-23 18:03 ` Ben Hutchings
2011-06-23 18:21 ` Mahesh Bandewar
2011-06-23 18:55 ` Ben Hutchings
2011-06-23 20:38 ` Mahesh Bandewar
2011-06-20 19:14 ` [RFT PATCH 8/9] net: extend netdev_features_t to 64 bits Michał Mirosław
2011-06-20 19:14 ` [RFT PATCH 6/9] net: ethtool: use C99 array initialization for feature-names table Michał Mirosław
2011-06-20 19:35 ` [RFT PATCH 0/9] Cleanup and extension of netdev features David Miller
2011-06-20 19:47 ` Michał Mirosław
2011-06-20 19:55 ` [IGNORE PATCH 1/9] Intel net drivers: convert to ndo_fix_features Michał Mirosław
2011-06-21 21:43 ` [RFT PATCH 0/9] Cleanup and extension of netdev features Ben Greear
2011-06-21 21:52 ` Ben Hutchings
2011-06-21 23:27 ` Jeff Kirsher
2011-06-23 17:42 ` Mahesh Bandewar
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