lkml.org 
[lkml]   [2008]   [Sep]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v6] Unified trace buffer

    On Fri, 26 Sep 2008, Richard Holden wrote:

    > On 9/26/08 12:05 PM, "Steven Rostedt" <rostedt@goodmis.org> wrote:
    >
    > > ring_buffer_alloc: create a new ring buffer. Can choose between
    > > overwrite or consumer/producer mode. Overwrite will
    > > overwrite old data, where as consumer producer will
    > > throw away new data if the consumer catches up with the
    > > producer. The consumer/producer is the default.
    >
    > Forgive me if I've gotten this wrong but the terminology seems backwards
    > Here, I would think we only throw away new data if the producer catches up
    > with the consumer, if the consumer catches up with the producer we're
    > reading data as fast as it's being written.

    Argh! Yes. I'm the one that is backwards ;-)

    Yeah, that is what I meant. Don't you know? You are suppose to understand
    what I mean, not what I say :)

    >
    > >
    > > ring_buffer_write: writes some data into the ring buffer.
    > >
    > > ring_buffer_peek: Look at a next item in the cpu buffer.
    > > ring_buffer_consume: get the next item in the cpu buffer and
    > > consume it. That is, this function increments the head
    > > pointer.
    >
    > Here too, I would think that consuming data would modify the tail pointer.

    I always get confused with the translation of what the head/tail to
    producer/consumer.

    Here I have the producer adding to the tail, and the consumer reading from
    the head. Perhaps this is backwards? I could change it.

    s/head/foobar/g
    s/tail/head/g
    s/foobar/tail/g

    That could do it.


    > >
    > > Signed-off-by: Steven Rostedt <srostedt@redhat.com>
    >
    > Just trying to understand the terminology before I look at the code so I'm
    > sorry if I have just completely misunderstood.

    Sure, thanks.

    -- Steve



    \
     
     \ /
      Last update: 2008-09-26 20:43    [W:0.024 / U:0.244 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site