e940eb3c1b
Yunsheng Lin says:
====================
Some optimization for lockless qdisc
Patch 1: remove unnecessary seqcount operation.
Patch 2: implement TCQ_F_CAN_BYPASS.
Patch 3: remove qdisc->empty.
Performance data for pktgen in queue_xmit mode + dummy netdev
with pfifo_fast:
threads unpatched patched delta
1 2.60Mpps 3.21Mpps +23%
2 3.84Mpps 5.56Mpps +44%
4 5.52Mpps 5.58Mpps +1%
8 2.77Mpps 2.76Mpps -0.3%
16 2.24Mpps 2.23Mpps -0.4%
Performance for IP forward testing: 1.05Mpps increases to
1.16Mpps, about 10% improvement.
V3: Add 'Acked-by' from Jakub and 'Tested-by' from Vladimir,
and resend based on latest net-next.
V2: Adjust the comment and commit log according to discussion
in V1.
V1: Drop RFC tag, add nolock_qdisc_is_empty() and do the qdisc
empty checking without the protection of qdisc->seqlock to
aviod doing unnecessary spin_trylock() for contention case.
RFC v4: Use STATE_MISSED and STATE_DRAINING to indicate non-empty
qdisc, and add patch 1 and 3.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.