lkml.org 
[lkml]   [2010]   [Nov]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [RFC][PATCH 0/2] tracing: Have trace_printk()s in the events/ directory
    From
    Date
    On Thu, 2010-11-18 at 11:41 +0100, Peter Zijlstra wrote:
    > On Wed, 2010-11-17 at 22:58 -0500, Steven Rostedt wrote:
    > > For example, I added a trace_printk() in kernel/sched.c at line 2180
    > > and it creates:
    > >
    > > # ls /debug/tracing/events/printk/kernel/sched.c/2180/
    > > enable format
    > >
    > > The format is the printk format:
    > >
    > > # cat /debug/tracing/events/printk/kernel/sched.c/2180/format
    > > "migrate task %s:%d"
    >
    > *groan*, so you're creating a tracepoint per instance?
    >
    > That's going to be massive pain for perf.. I really don't see the point
    > in splitting all that out.

    a) The file directory was what was asked about in the referenced email.
    b) This is just an example of a way to display it to the user, which
    seems to be very intuitive.
    c) Perf can implement the details anyway it wants. It can make a single
    tracepoint callback and have the enabling of the points as a special
    filter.
    d) This was just an RFC that Frederic asked if I would do. I thought it
    would be a fun challenge and did it. Let it bit rot in hell for all I
    care, I wasn't taking it any further anyway.

    -- Steve




    \
     
     \ /
      Last update: 2010-11-18 13:13    [W:4.019 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site