On Tue, Oct 13, 2015 at 5:47 AM, Liu Ting ting.liu@freescale.com wrote:
When upgrading meta-linaro/meta-linaro-toolchain from daisy to fido, we faced drastic performance downgrade (-34.06%) on linux ipv4 forwarding. The board is ls1021atwr (ARM Cortex-A7 MPCore compliant with ARMv7-A architecture). We did some investigation, and suspected that it is caused by the toolchain upgrade. Did someone meet similar issue?
I haven't heard of any such issue, but that doesn't mean much, as I don't read kernel mailing lists, and don't have full knowledge of all gcc bugs that have been privately and publicly reported. Basically, without a testcase, that we can use to reproduce the problem, you are unlikely to get much useful info from a toolchain developer. And if the testcase requires building a linux system from scratch, then that may be too much trouble for us to follow up on. You might try asking some linaro kernel developers about this if you haven't already. They would know more about kernel performance issues.
Jim