Hi, Peter, On Tue, Jul 6, 2021 at 9:48 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > On Tue, Jul 06, 2021 at 12:18:18PM +0800, Huacai Chen wrote: > > +/* > > + * Loongson-3's SFB (Store-Fill-Buffer) may buffer writes indefinitely when a > > + * tight read loop is executed, because reads take priority over writes & the > > + * hardware (incorrectly) doesn't ensure that writes will eventually occur. > > + * > > + * Since spin loops of any kind should have a cpu_relax() in them, force an SFB > > + * flush from cpu_relax() such that any pending writes will become visible as > > + * expected. > > + */ > > +#define cpu_relax() smp_mb() > > Guys! You've not fixed that utter trainwreck ?!? You've taped out a > whole new architecture and you're keeping this? It is ugly of course, but it hasn't been fixed now. Huacai
