On 2019-02-09 03:25, Mo Zhou wrote:
Hi folks,
For most programs the "-march=native" option is not expected to bring
any
significant performance improvement. However for some scientific
applications
this proposition doesn't hold. When I was creating the tensorflow
debian
package, I observed a significant performance gap between generic code
and
kabylake (Intel 7XXX Series) code[1].
...
Generally speaking, in order to bump the ISA baseline for a given
package, one
could add the -march=xxx flag to {C,CXX,F}FLAGS by modifying
debian/rules.
However SIMDebian employes a more economic approach to this end:
forking
dpkg[5] and injecting -march=xxx flag to the system default flag list.
With the
resulting dpkg package, most debian packages could be rebuilt with
bumped ISA
baseline without any code modification.
I think it would be more constructive to provide arch-specific packages
for eigen/blas etc on amd64 which Conflict/Replace/Provide the standard
packages.
That way a local administrator can choose to install them if they help
improve performance.
Hacking dpkg itself for this purpose and forking an entire linux
distribution is way too invasive and distracts from solving the actual
problem.
Drew
