Doug / smarc-fsl-linux-kernel

16 May, 2010

1 commit

  • 3b098e2d7   net: Consistent skb timestamping ... Browse Code »

    With RPS inclusion, skb timestamping is not consistent in RX path.

    If netif_receive_skb() is used, its deferred after RPS dispatch.

    If netif_rx() is used, its done before RPS dispatch.

    This can give strange tcpdump timestamps results.

    I think timestamping should be done as soon as possible in the receive
    path, to get meaningful values (ie timestamps taken at the time packet
    was delivered by NIC driver to our stack), even if NAPI already can
    defer timestamping a bit (RPS can help to reduce the gap)

    Tom Herbert prefer to sample timestamps after RPS dispatch. In case
    sampling is expensive (HPET/acpi_pm on x86), this makes sense.

    Let admins switch from one mode to another, using a new
    sysctl, /proc/sys/net/core/netdev_tstamp_prequeue

    Its default value (1), means timestamps are taken as soon as possible,
    before backlog queueing, giving accurate timestamps.

    Setting a 0 value permits to sample timestamps when processing backlog,
    after RPS dispatch, to lower the load of the pre-RPS cpu.

    Signed-off-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric Dumazet
     

14 Apr, 2009

1 commit

03 Apr, 2009

2 commits

  • 45dad7bd9   documentation: fix unix_dgram_qlen description ... Browse Code »

    Previous description about system parameter in /proc/sys/net/unix/ is
    wrong (or missed). Simply add a new description about unix_dgram_qlen
    according to latest kernel.

    Signed-off-by: Li Xiaodong
    Cc: "David S. Miller"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Li Xiaodong
     
  • 760df93ec   documentation: update Documentation/filesystem/proc.txt and Documentation/sysctls ... Browse Code »

    Now /proc/sys is described in many places and much information is
    redundant. This patch updates the proc.txt and move the /proc/sys
    desciption out to the files in Documentation/sysctls.

    Details are:

    merge
    - 2.1 /proc/sys/fs - File system data
    - 2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem
    - 2.17 /proc/sys/fs/epoll - Configuration options for the epoll interface
    with Documentation/sysctls/fs.txt.

    remove
    - 2.2 /proc/sys/fs/binfmt_misc - Miscellaneous binary formats
    since it's not better then the Documentation/binfmt_misc.txt.

    merge
    - 2.3 /proc/sys/kernel - general kernel parameters
    with Documentation/sysctls/kernel.txt

    remove
    - 2.5 /proc/sys/dev - Device specific parameters
    since it's obsolete the sysfs is used now.

    remove
    - 2.6 /proc/sys/sunrpc - Remote procedure calls
    since it's not better then the Documentation/sysctls/sunrpc.txt

    move
    - 2.7 /proc/sys/net - Networking stuff
    - 2.9 Appletalk
    - 2.10 IPX
    to newly created Documentation/sysctls/net.txt.

    remove
    - 2.8 /proc/sys/net/ipv4 - IPV4 settings
    since it's not better then the Documentation/networking/ip-sysctl.txt.

    add
    - Chapter 3 Per-Process Parameters
    to descibe /proc//xxx parameters.

    Signed-off-by: Shen Feng
    Cc: Randy Dunlap
    Cc: "David S. Miller"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Shen Feng