Messages in this thread | | | Date | Mon, 28 Oct 2013 14:42:13 +0200 | From | Pekka Enberg <> | Subject | Re: [PATCH v4 2/3] Support for perf to probe into SDT markers: |
| |
On 10/28/13 1:23 PM, Masami Hiramatsu wrote: > By the way, what happens if multiple binaries has same SDT marker? > Yeah, perf list shows just one and ignores others. However, if we > probe one, and run binary which use the other one, user will never > see the marker. > > So, it still needs a concrete binary path to list or, we should > support a syntax which specify actual binary, as like as below. > > perf probe 'my_event=%libc:setjmp@/lib64/libc.so.6' > > And perf list may show the marker as in same syntax (for copy&paste). > > # perf list --sdt > %libc:setjmp@/lib64/libc.so.6 > ... > > Note that we need '%' to separate namespace :(, since user can define > any marker(provider) name in their binary...
Sure, you need to support that sort of 'fully qualified name' for duplicate symbols but the default 'libc:setjmp' should still point to system libc.
This is an example where tracing libc that's relevant to most of the users should take priority over the 'duplicate marker in obscure executable' corner case case.
Pekka
| |