svn commit: r323516 - in head/sys: dev/bnxt dev/e1000 kern net sys

Wed Sep 13 19:49:57 UTC 2017

On Wed, Sep 13, 2017 at 7:45 AM, Cy Schubert <Cy.Schubert at komquats.com>
wrote:

> In message <CANCZdfoDjhY0HW+YuErVDRJ0YC4SPXTL0GBYFrTJvpax0
> KcmTA at mail.gmail.c
> om>
> , Warner Losh writes:
> > --001a1141f15ac444250559123c56
> > Content-Type: text/plain; charset="UTF-8"
> >
> > On Wed, Sep 13, 2017 at 1:11 AM, Cy Schubert <Cy.Schubert at komquats.com>
> > wrote:
> >
> > > In message <4D5AE475-5A38-4429-8B71-DBECDFB0A1FF at gmail.com>, Ngie
> Cooper
> > > writes
> > > :
> > > >
> > > > > On Sep 12, 2017, at 18:18, Stephen Hurd <shurd at FreeBSD.org> wrote:
> > > > >
> > > > > Author: shurd
> > > > > Date: Wed Sep 13 01:18:42 2017
> > > > > New Revision: 323516
> > > > > URL: https://svnweb.freebsd.org/changeset/base/323516
> > > > >
> > > > > Log:
> > > > >  Roll up iflib commits from github.  This pulls in most of the work
> > > done
> > > > >  by Matt Macy as well as other changes which he has accepted via
> pull
> > > > >  request to his github repo at https://github.com/mattmacy/
> networking/
> > > > >
> > > > >  This should bring -CURRENT and the github repo into close enough
> sync
> > > to
> > > > >  allow small feature branches rather than a large chain of
> > > interdependant
> > > > >  patches being developed out of tree.  The reset of the
> synchronization
> > > > >  should be able to be completed on github by splitting the
> remaining
> > > > >  changes that are not yet ready into short feature branches for
> later
> > > > >  review as smaller commits.
> > > > >
> > > > >  Here is a summary of changes included in this patch:
> > > > >
> > > > >  1)  More checks when INVARIANTS are enabled for eariler problem
> > > > >      detection
> > > > >  2)  Group Task Queue cleanups
> > > > >      - Fix use of duplicate shortdesc for gtaskqueue malloc type.
> > > > >        Some interfaces such as memguard(9) use the short
> description to
> > > > >        identify malloc types, so duplicates should be avoided.
> > > > >  3)  Allow gtaskqueues to use ithreads in addition to taskqueues
> > > > >      - In some cases, this can improve performance
> > > > >  4)  Better logging when taskqgroup_attach*() fails to set
> interrupt
> > > > >      affinity.
> > > > >  5)  Do not start gtaskqueues until they're needed
> > > > >  6)  Have mp_ring enqueue function enter the ABDICATED rather than
> BUSY
> > > > >      state.  This moves the TX to the gtaskq and allows processing
> to
> > > > >      continue faster as well as make TX batching more likely.
> > > > >  7)  Add an ift_txd_errata function to struct if_txrx.  This allows
> > > > >      drivers to inspect/modify mbufs before transmission.
> > > > >  8)  Add a new IFLIB_NEED_ZERO_CSUM for drivers to indicate they
> need
> > > > >      checksums zeroed for checksum offload to work.  This avoids
> > > modifying
> > > > >      packet data in the TX path when possible.
> > > > >  9)  Use ithreads for iflib I/O instead of taskqueues
> > > > >  10) Clean up ioctl and support async ioctl functions
> > > > >  11) Prefetch two cachlines from each mbuf instead of one up to
> 128B.
> > > We
> > > > >      often need to parse packet header info beyond 64B.
> > > > >  12) Fix potential memory corruption due to fence post error in
> > > > >      bit_nclear() usage.
> > > > >  13) Improved hang detection and handling
> > > > >  14) If the packet is smaller than MTU, disable the TSO flags.
> > > > >      This avoids extra packet parsing when not needed.
> > > > >  15) Move TCP header parsing inside the IS_TSO?() test.
> > > > >      This avoids extra packet parsing when not needed.
> > > > >  16) Pass chains of mbufs that are not consumed by lro to
> if_input()
> > > > >      rather call if_input() for each mbuf.
> > > > >  17) Re-arrange packet header loads to get as much work as possible
> > > done
> > > > >      before a cache stall.
> > > > >  18) Lock the context when calling IFDI_ATTACH_PRE()/IFDI_ATTACH_
> > > POST()/
> > > > >      IFDI_DETACH();
> > > > >  19) Attempt to distribute RX/TX tasks across cores more sensibly,
> > > > >      especially when RX and TX share an interrupt.  RX will
> attempt to
> > > > >      take the first threads on a core, and TX will attempt to take
> > > > >      successive threads.
> > > > >  20) Allow iflib_softirq_alloc_generic() to request affinity to the
> > > same
> > > > >      cpus an interrupt has affinity with.  This allows TX queues to
> > > > >      ensure they are serviced by the socket the device is on.
> > > > >  21) Add new iflib sysctls to net.iflib:
> > > > >      - timer_int - interval at which to run per-queue timers in
> ticks
> > > > >      - force_busdma
> > > > >  22) Add new per-device iflib sysctls to dev.X.Y.iflib
> > > > >      - rx_budget allows tuning the batch size on the RX path
> > > > >      - watchdog_events Count of watchdog events seen since load
> > > > >  23) Fix error where netmap_rxq_init() could get called before
> > > > >      IFDI_INIT()
> > > > >  24) e1000: Fixed version of r323008: post-cold sleep instead of
> DELAY
> > > > >      when waiting for firmware
> > > > >      - After interrupts are enabled, convert all waits to sleeps
> > > > >      - Eliminates e1000 software/firmware synchronization busy
> waits
> > > after
> > > > >        startup
> > > > >  25) e1000: Remove special case for budget=1 in em_txrx.c
> > > > >      - Premature optimization which may actually be incorrect with
> > > > >        multi-segment packets
> > > > >  26) e1000: Split out TX interrupt rather than share an interrupt
> for
> > > > >      RX and TX.
> > > > >      - Allows better performance by keeping RX and TX paths
> separate
> > > > >  27) e1000: Separate igb from em code where suitable
> > > > >      Much easier to understand separate functions and "if (is_igb)"
> > > than
> > > > >      previous tests like "if (reg_icr & (E1000_ICR_RXSEQ |
> > > E1000_ICR_LSC))"
> > > > >
> > > > >  #blamebruno
> > > > >
> > > > >  Reviewed by:    sbruno
> > > > >  Approved by:    sbruno (mentor)
> > > > >  Sponsored by:    Limelight Networks
> > > > >  Differential Revision:    https://reviews.freebsd.org/D12235
> > > >
> > > > *gasps at the LoC count and number of changed drivers*
> > > >
> > > > Could someone please better break this up in the future..?
> > >
> > > Agreed. Down the road parsing out individual commits in this jumbo
> commit
> > > will be difficult to parse. IMO this may as well have simply been,
> import
> > > from https://github.com/mattmacy/networking/, just like Mr. Torvalds
> does
> > > at kernel.org. I expect to see a commit like this there but not here.
> Can
> > > we break this down to its functional commits?
> >
> >
> > I use git + svn for other things. It should be possible to use that to
> push
> > the changes in 'machine gun style' (meaning 27 changes pushed so fast
> they
> > show up as 27 consecutive r numbers). I do change curation, etc with it
> so
> > I get good sized commits. That's why you'll often see 10 or 20 commits
> from
> > me show up in a matter of a couple of minutes. git svn dcommit is to
> blame,
> > but so is about two dozen git rebases and other git crazy along the way.
> > Something like that would be useful here. I'd be quite happy to walk
> people
> > through my setup if it helps to reduce this.
>
> I'm interested.

Start with

https://wiki.freebsd.org/GitWorkflow/GitSvn

Once you get through that, we can chat...

Warner