* Eric Blake (ebl...@redhat.com) wrote: > On 11/12/2015 12:56 PM, Dr. David Alan Gilbert wrote: > > >> One thing I still can't understand, why the unit test in host environment > >> shows > >> 'memcmp()' have better performance? > > Have you tried running under a profiler, to see if there are hotspots or > at least get an idea of where the time is being spent? > > > > > Are you aware of any program other than QEMU that also wants to do something > > similar? Finding whether a block of memory is zero, sounds like something > > that would be useful in lots of places, I just can't think which ones. > > At least dd, cp, and probably several other utilities. It would be nice > to post an RFE to glibc to see if they can come up with a dedicated > interface that is faster than memcmp(), although that still only helps > us when targetting a system new enough to have that interface.
I've just posted that RFE: https://sourceware.org/bugzilla/show_bug.cgi?id=19920 Dave > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
