>>> On 28.03.19 at 09:03, <jbeul...@suse.com> wrote:
> For core parking I wonder whether core_parking_helper()
> shouldn't, first of all, invoke cpu_{up,down}_helper(). This
> wouldn't be enough, though - the policy hooks need to honor
> opt_smt as well.Actually no, there was no problem at the time there: With opt_smt set to false, no secondary thread would ever have made it into core_parking_cpunum[] (that's where CPU numbers to be passed to cpu_up() get taken from). A problem here was introduced only by Andrew's 2bed1bc241, making it possible for opt_smt to change at runtime. I think I'll make a patch to have smt_up_down_helper() call into core-parking code to purge CPUs from core_parking_cpunum[] as needed. The interaction of core-parking and xen-hptool activities is up for discussion anyway, I think. At least to me it's not immediately clear which of the two should take priority. Allowing admins to shoot themselves in the foot (as we appear to do now) is a reasonable possibility, but not the only one, the more that the platform is liable to notice higher power consumption and to subsequently request offlining of CPUs again anyway. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
