On Mon, Sep 30, 2013 at 05:44:41PM +0200, Stephane Eranian wrote: > Hi, > > I was alerted by people trying to use the PERF_RECORD_MMAP2 > record to disambiguate virtual address mappings that there is a case > where the record does not contain enough information. > > As you know, the MMAP2 record adds the major, minor, ino number, > inode generation numbers to a mapping. But it does that only for > file or pseudo -file backed mappings. That covers file mmaps and also > SYSV shared memory segments. > > However there is a another kind of situation that arises in some > multi-process benchmarks where a region of memory is cloned > using VM_CLONE. As such, the virtual addresses match between > the processes but the major, minor, inode, inode generation fields > are all zeroes because there is no inode associated with the mapping. > Yet, it is important for the tool to know the mappings between the > processes are pointing to the same physical data. > > We need to cover this case and I am seeking for advice on how to > best address this need given that we discarded using the plain physical > address for disambiguation.
Urgh.. who in his bloody mind is playing VM_CLNOE games that is not pthread_creatE() ? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
