Re: SystemTap on 2.6.23-rc8-mm2

[Andy Gospodarek <gospo at redhat dot com>]

On Thu, Oct 04, 2007 at 03:07:00PM -0500, David Smith wrote:
> David Smith wrote:
> >Mike Mason wrote:
> >>Just a heads up... I had to patch buildrun.cxx to get scripts to build 
> >>on 2.6.23-rc8-mm2 (CFLAGS changed to KBUILD_CFLAGS, CPPFLAGS changed 
> >>to KBUILD_CPPFLAGS).  I've attached the patch below.  I don't know 
> >>when or if this change will go into Linus' kernel.  I'm also not sure 
> >>of the best way to ensure the correct CFLAGS are used in build_run.cxx 
> >>(maybe check s.kernel_release?).
> >
> >I've seen this also (and in fact I meant to check something in but got 
> >distracted by my other marker work).  I believe my solution will be 
> >backwards compatible to 2.6.9 kernels - I've tested it on RHEL4 but I 
> >wanted to test f7 and RHEL5 to make sure I didn't break anything.
> 
> I tested this on RHEL4, RHEL5, and f7.  It seemed to work correctly 
> everywhere so I've checked my changes.
> 

Interestingly I just pulled the latest sources and tried against Dave
Miller's net-2.6.24 tree and I'm getting the following errors:

WARNING: ignored message of type 5

For my printfs.  Here's a log:

# /usr/local/bin/stap -vv dma_alloc_coherent.stp
SystemTap translator/driver (version 0.6/0.129 built 2007-10-04)
Copyright (C) 2005-2007 Red Hat, Inc. and others
This is free software; see the source for copying conditions.
Created temporary directory "/tmp/stapWK9BBS"
Searched '/usr/local/share/systemtap/tapset/x86_64/*.stp', found 1
Searched '/usr/local/share/systemtap/tapset/*.stp', found 36
Pass 1: parsed user script and 37 library script(s) in
190usr/0sys/206real ms.
probe dma_alloc_coherent@arch/x86_64/kernel/pci-dma.c:74 kernel
section=.text pc=0xffffffff8021230e
Pass 2: analyzed script: 1 probe(s), 1 function(s), 0 embed(s), 0
global(s) in 200usr/70sys/265real ms.
Pass 3: using cached
/root/.systemtap/cache/37/stap_3785b7bedca3b118c37dcdc110ec39d6_550.c
Pass 4: using cached
/root/.systemtap/cache/37/stap_3785b7bedca3b118c37dcdc110ec39d6_550.ko
Pass 5: starting run.
Running /usr/local/bin/staprun -v -d 6449
/tmp/stapWK9BBS/stap_3785b7bedca3b118c37dcdc110ec39d6_550.ko
WARNING: ignored message of type 5
stapio:cleanup_and_exit:216 CLEANUP AND EXIT  closed=0
stapio:cleanup_and_exit:229 closing control channel
Pass 5: run completed in 30usr/50sys/12659real ms.
Running rm -rf /tmp/stapWK9BBS
[root@core2 stap]# cat dma_alloc_coherent.stp


probe kernel.function("dma_alloc_coherent")
{
        printf("dma_alloc_coherent: size = 0x%x\n",$size);
}


The message:

WARNING: ignored message of type 5

only comes out when I force a call to dma_alloc_coherent (one can do
this by modprobing most any network driver).

Any thoughts?  I dug through the code and I see where the error is
coming from (mainloop.c), but I'm not familiar enough with the stap
interface to know what's happening.

Thanks,

-andy