On 07/07/2017 09:36 PM, Krister Johansen wrote: > On Thu, Jul 06, 2017 at 04:41:30PM -0300, Arnaldo Carvalho de Melo wrote: >> Em Wed, Jul 05, 2017 at 06:48:08PM -0700, Krister Johansen escreveu: >>> Teach perf how to resolve symbols from binaries that are in a different >>> mount namespace from the tool. This allows perf to generate meaningful >>> stack traces even if the binary resides in a different mount namespace >>> from the tool. >> >> I was trying to find a way to test after applying each of the patches in >> this series, when it ocurred to me that if a process that appears on a >> perf.data file has exit, how can we access /proc/%ITS_PID/something? > > You're correct. We can't access /proc/<PID>/whatever once the process > has exited. That was the impeteus for patches 4 and 6, which allow us > to capture the binary (and debuginfo, if it exists) into the buildid > cache so that if we do have a trace that exists after a process or > container exists, we'll still be able to resolve some of the symbols. > > -K >
Any ideas on how to extend this to be able to resolve symbols after the process/container exited? I believe it boils down on how to interpret the mnt inode number in the PERF_RECORD_NAMESPACE record... Can this be done post-mortem? Maybe the PERF_RECORD_NAMESPACE record has to contain more data than just the inode number? -- Thomas Richter, Dept 3303, IBM LTC Boeblingen Germany -- Vorsitzende des Aufsichtsrats: Martina Koederitz Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294
