Messages in this thread |  | | From | Thomas Gleixner <> | Subject | Re: [PATCH v3 3/5] x86/mm: Optionally flush L1D on context switch | Date | Fri, 04 Dec 2020 22:21:09 +0100 |
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On Fri, Nov 27 2020 at 17:59, Balbir Singh wrote: > > + /* > + * Flush only if SMT is disabled as per the contract, which is checked > + * when the feature is enabled. > + */ > + if (sched_smt_active() && !this_cpu_read(cpu_info.smt_active) && > + (prev_mm & LAST_USER_MM_L1D_FLUSH)) > + l1d_flush_hw();
So if SMT is completely disabled then no flush? Shouldn't the logic be:
if ((!sched_smt_active() || !this_cpu_read(cpu_info.smt_active) && (prev_mm & LAST_USER_MM_L1D_FLUSH))
Hmm?
But that's bad, because it's lot's of conditions to evaluate for every switch_mm where most of them are not interested in it at all.
Let me read through the rest of the pile.
Thanks,
tglx
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