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  1. 06 Apr, 2011 33 commits
  3. 05 Apr, 2011 7 commits
    • Ben Hutchings's avatar
      sfc: Implement ethtool_ops::set_phys_id instead of ethtool_ops::phys_id · c5e129ac
      Ben Hutchings authored 
      Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
      c5e129ac
    • Ben Hutchings's avatar
      ethtool: Change ETHTOOL_PHYS_ID implementation to allow dropping RTNL · 68f512f2
      Ben Hutchings authored 
      The ethtool ETHTOOL_PHYS_ID command runs for an arbitrarily long
period of time, holding the RTNL lock.  This blocks routing updates,
device enumeration, and various important operations that one might
want to keep running while hunting for the flashing LED.

We need to drop the RTNL lock during this operation, but currently the
core implementation is a thin wrapper around a driver operation and
drivers may well depend upon holding the lock.

Define a new driver operation 'set_phys_id' with an argument that sets
the ID indicator on/off/inactive/active (the last optional, for any
driver or firmware that prefers to handle blinking asynchronously).
When this is defined, the ethtool core drops the lock while waiting
and only acquires it around calls to this operation.

Deprecate the 'phys_id' operation in favour of this.  It can be
removed once all in-tree drivers are converted.
Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
      68f512f2
    • Ben Hutchings's avatar
      ethtool: Fill out and update comment for struct ethtool_ops · 8717d07b
      Ben Hutchings authored 
      Briefly document all operations (except get_rx_ntuple), including
whether they may return an error code and whether they are deprecated.
Also mention some things that should be handled by the ethtool core
rather than by drivers.

Briefly document general requirements for callers.
Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
      8717d07b
    • Ben Hutchings's avatar
      ethtool: Convert struct ethtool_ops comment to kernel-doc format · e20b5b61
      Ben Hutchings authored 
      Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
      e20b5b61
    • Ben Hutchings's avatar
      sfc: Implement generic features interface · abfe9039
      Ben Hutchings authored 
      Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
      abfe9039
    • Ben Hutchings's avatar
      sfc: Enable all TSO features on VLANs · f82d9a67
      Ben Hutchings authored 
      The TSO code already supports IPv6 on VLAN, so enable it.
Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
      f82d9a67
    • Tom Herbert's avatar
      net: Allow no-cache copy from user on transmit · c6e1a0d1
      Tom Herbert authored 
      This patch uses __copy_from_user_nocache on transmit to bypass data
cache for a performance improvement.  skb_add_data_nocache and
skb_copy_to_page_nocache can be called by sendmsg functions to use
this feature, initial support is in tcp_sendmsg.  This functionality is
configurable per device using ethtool.

Presumably, this feature would only be useful when the driver does
not touch the data.  The feature is turned on by default if a device
indicates that it does some form of checksum offload; it is off by
default for devices that do no checksum offload or indicate no checksum
is necessary.  For the former case copy-checksum is probably done
anyway, in the latter case the device is likely loopback in which case
the no cache copy is probably not beneficial.

This patch was tested using 200 instances of netperf TCP_RR with
1400 byte request and one byte reply.  Platform is 16 core AMD x86.

No-cache copy disabled:
   672703 tps, 97.13% utilization
   50/90/99% latency:244.31 484.205 1028.41

No-cache copy enabled:
   702113 tps, 96.16% utilization,
   50/90/99% latency 238.56 467.56 956.955

Using 14000 byte request and response sizes demonstrate the
effects more dramatically:

No-cache copy disabled:
   79571 tps, 34.34 %utlization
   50/90/95% latency 1584.46 2319.59 5001.76

No-cache copy enabled:
   83856 tps, 34.81% utilization
   50/90/95% latency 2508.42 2622.62 2735.88

Note especially the effect on latency tail (95th percentile).

This seems to provide a nice performance improvement and is
consistent in the tests I ran.  Presumably, this would provide
the greatest benfits in the presence of an application workload
stressing the cache and a lot of transmit data happening.
Signed-off-by: default avatarTom Herbert <therbert@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c6e1a0d1
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