Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1528925

Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage!

From Steven Rostedt <rostedt@goodmis.org>
Newsgroups linux.kernel
Subject Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage!
Date 2016-11-24 03:10 +0100
Message-ID <sGRE6-4x0-9@gated-at.bofh.it> (permalink)
References (4 earlier) <sG0T7-4em-21@gated-at.bofh.it> <sG1ct-4DY-23@gated-at.bofh.it> <sG1ct-4DY-21@gated-at.bofh.it> <sG1vP-4LN-1@gated-at.bofh.it> <sG1Fw-4P0-21@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

On Mon, 21 Nov 2016 10:37:00 -0800
Andi Kleen <andi@firstfloor.org> wrote:

> > It tries to be optimized. I "unoptimized" it a while back to pull out
> > all the inlines that were done in the tracepoint itself. That is, the
> > trace_<tracepoint>() function is inlined in the code itself. By
> > breaking that up a bit, I was able to save a bunch of text because the
> > tracepoints were bloating the kernel tremendously.  
> 
> Just adding a few inlines won't fix the gigantic bloat that is currently
> there. See the PT trace I posted earlier (it was even truncated, it's
> actually worse). Just a single enabled trace point took about a us.
> 
> POPF can cause some serializion but it won't be more than a few tens
> of cycles, which would be a few percent at best.
> 
> Here is it again untruncated:
> 
> http://halobates.de/tracepoint-trace
> 

I took a look at this and forced some more functions to be inlined. I
did a little tweaking here and there. Could you pull my tree and see if
things are better?  I don't currently have the hardware to run this
myself.

git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git

  branch: ftrace/core


Thanks!

-- Steve

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Jiri Olsa <jolsa@redhat.com> - 2016-11-21 02:00 +0100
  Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-11-21 10:10 +0100
    Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Peter Zijlstra <peterz@infradead.org> - 2016-11-21 10:50 +0100
      Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-11-21 12:10 +0100
  Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Peter Zijlstra <peterz@infradead.org> - 2016-11-21 10:30 +0100
    Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Jiri Olsa <jolsa@redhat.com> - 2016-11-21 10:40 +0100
      Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Peter Zijlstra <peterz@infradead.org> - 2016-11-21 10:50 +0100
        Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Jiri Olsa <jolsa@redhat.com> - 2016-11-21 12:30 +0100
          Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Peter Zijlstra <peterz@infradead.org> - 2016-11-21 12:40 +0100
            Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Jiri Olsa <jolsa@redhat.com> - 2016-11-21 13:50 +0100
      Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Peter Zijlstra <peterz@infradead.org> - 2016-11-21 14:00 +0100
        Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-21 15:30 +0100
          Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Peter Zijlstra <peterz@infradead.org> - 2016-11-21 15:40 +0100
            Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Borislav Petkov <bp@alien8.de> - 2016-11-21 16:40 +0100
              Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Peter Zijlstra <peterz@infradead.org> - 2016-11-21 16:50 +0100
                Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Borislav Petkov <bp@alien8.de> - 2016-11-21 17:10 +0100
        Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-21 15:30 +0100
    Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Andi Kleen <andi@firstfloor.org> - 2016-11-21 18:10 +0100
      Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Peter Zijlstra <peterz@infradead.org> - 2016-11-21 18:20 +0100
        Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Andi Kleen <andi@firstfloor.org> - 2016-11-21 18:50 +0100
          Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Andi Kleen <andi@firstfloor.org> - 2016-11-21 19:10 +0100
            Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-21 19:30 +0100
              Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Andi Kleen <andi@firstfloor.org> - 2016-11-21 19:40 +0100
                Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-21 20:10 +0100
                Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-21 20:20 +0100
                Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Andi Kleen <andi@firstfloor.org> - 2016-11-21 21:50 +0100
                Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-11-22 09:20 +0100
                Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-22 15:40 +0100
                Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Andi Kleen <andi@firstfloor.org> - 2016-11-22 20:10 +0100
                Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-24 03:10 +0100
          Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-21 19:10 +0100
        Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-21 19:00 +0100
          Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Steven Rostedt <rostedt@goodmis.org> - 2016-11-21 19:30 +0100
            Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-11-21 21:20 +0100

csiph-web