On 01/06/2018 09:33 AM, Dave Hansen wrote: > On 01/06/2018 06:41 AM, Konrad Rzeszutek Wilk wrote: >>> .macro DISABLE_IBRS >>> - ALTERNATIVE "jmp .Lskip_\@", "", X86_FEATURE_SPEC_CTRL >>> + testl $1, dynamic_ibrs >> On every system call we end up hammering on this 'dynamic_ibrs' >> variable. And it looks like it can be flipped via the IPI mechanism. >> >> Would it make sense for this to be per-cpu? > > It's probably better to either just make it __read_mostly or get the > static branches that folks were suggesting actually working. >
dynamic_ibrs is indeed declared __read_mostly +unsigned int dynamic_ibrs __read_mostly; +EXPORT_SYMBOL_GPL(dynamic_ibrs); Tim
