[Gluster-devel] gluster IRC and use systemtap can't output glusterfs backtrace

[Krishnan Parthasarathi]

To probe functions in specific translators you need to
specify the path to the corresponding .so file in the process
provider.

For eg, to probe functions in fuse translator,

stap -d /usr/local/sbin/glusterfs --ldd -e 'probe process("/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so").function("*"){print_ubacktrace()}'

The following is the output I see, when I write files using dd on
a GlusterFS native mount,

<snip>

0x31d7cf5e1d : clone+0x6d/0x90 [/usr/lib64/libc-2.17.so]
 0x7f7977a1c834 : fuse_resolve+0x74/0x4f0 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a1cd3e : fuse_resolve_all+0x8e/0xb0 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a1cd80 : fuse_resolve_and_resume+0x20/0x30 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a3507e : fuse_thread_proc+0x2ae/0x690 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x31d8407c53 : start_thread+0xc3/0x310 [/usr/lib64/libpthread-2.17.so]
 0x31d7cf5e1d : clone+0x6d/0x90 [/usr/lib64/libc-2.17.so]
 0x7f7977a1e4d0 : fuse_fd_ctx_get+0x0/0x40 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a1c84c : fuse_resolve+0x8c/0x4f0 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a1cd3e : fuse_resolve_all+0x8e/0xb0 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a1cd80 : fuse_resolve_and_resume+0x20/0x30 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a3507e : fuse_thread_proc+0x2ae/0x690 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x31d8407c53 : start_thread+0xc3/0x310 [/usr/lib64/libpthread-2.17.so]
 0x31d7cf5e1d : clone+0x6d/0x90 [/usr/lib64/libc-2.17.so]
 0x7f7977a1c1e0 : fuse_resolve_continue+0x0/0x100 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a1c9f8 : fuse_resolve+0x238/0x4f0 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a1cd3e : fuse_resolve_all+0x8e/0xb0 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a1cd80 : fuse_resolve_and_resume+0x20/0x30 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x7f7977a3507e : fuse_thread_proc+0x2ae/0x690 [/usr/local/lib/glusterfs/3.5qa2/xlator/mount/fuse.so]
 0x31d8407c53 : start_thread+0xc3/0x310 [/usr/lib64/libpthread-2.17.so]
 0x31d7cf5e1d : clone+0x6d/0x90 [/usr/lib64/libc-2.17.so]

</snip>

Hope that helps,
Krish


----- Original Message -----
> See inline for response.
> 
> ----- Original Message -----
> > hi everyone!
> > I meet three question:
> > 
> > question one:
> > 
> > I use IRC client(mirc) config server is:  irc.freenode.net  or  irc.gnu.org
> > but always can't connect, follwing errors:
> > Connect retry #1 irc,freenode,net (6667) (dns pool)
> > unable to connect server (connect timed out)
> > 
> > 
> > 
> > question two:
> > I system is centos6.4，glusterfs version is 3.4.
> > I want to use systemtap watch glusterfs function backtrace,
> > when I configure glusterfs source code, execute the following operation:
> > ./configure --enable--systemtap
> > but checking dtrace happen error，because in my system，no dtrace，my
> > question is --enable--systemtap why need dtrace?  it must have dtrace?
> 
> I think the systemtap folks have retained certain symbols from dtrace
> so that code instrumented with systemtap user specified probes are compatible
> with systems that have dtrace but not systemtap in them.
> 
> > 
> > question three:
> > when I do io test in glusterfs client. I execute following command:
> > stap -d /usr/local/sbin/glusterfs --ldd -e 'probe
> > process("glusterfs").function("*"){print_ubacktrace()}'
> > 
> > the result is  there is nothing output, and  the stap command S state,
> > no return.
> 
> For 'process' systemtap provider, you don't need to compile glusterfs with
> "--enable-systemtap". I am not sure why you are not seeing any of the probes
> firing in your stap script. Let me try this same and share my results on this
> thread.
> 
> Hope that helps,
> Krish
> 
> > 
> > thank you answer me!
> > _______________________________________________
> > Gluster-devel mailing list
> > Gluster-devel at gluster.org
> > http://supercolony.gluster.org/mailman/listinfo/gluster-devel
> > 
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