On Tue, 2 Jul 2019, Nadav Amit wrote: > SGI UV support is outdated and not maintained, and it is not clear how > it performs relatively to non-UV. Remove the code to simplify the code.
You should at least Cc the SGI/HP folks on that. They are still around. Done so. > Cc: Peter Zijlstra <[email protected]> > Cc: Dave Hansen <[email protected]> > Suggested-by: Andy Lutomirski <[email protected]> > Signed-off-by: Nadav Amit <[email protected]> > --- > arch/x86/mm/tlb.c | 25 ------------------------- > 1 file changed, 25 deletions(-) > > diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c > index b47a71820f35..64afe1215495 100644 > --- a/arch/x86/mm/tlb.c > +++ b/arch/x86/mm/tlb.c > @@ -689,31 +689,6 @@ void native_flush_tlb_multi(const struct cpumask > *cpumask, > trace_tlb_flush(TLB_REMOTE_SEND_IPI, > (info->end - info->start) >> PAGE_SHIFT); > > - if (is_uv_system()) { > - /* > - * This whole special case is confused. UV has a "Broadcast > - * Assist Unit", which seems to be a fancy way to send IPIs. > - * Back when x86 used an explicit TLB flush IPI, UV was > - * optimized to use its own mechanism. These days, x86 uses > - * smp_call_function_many(), but UV still uses a manual IPI, > - * and that IPI's action is out of date -- it does a manual > - * flush instead of calling flush_tlb_func_remote(). This > - * means that the percpu tlb_gen variables won't be updated > - * and we'll do pointless flushes on future context switches. > - * > - * Rather than hooking native_flush_tlb_multi() here, I think > - * that UV should be updated so that smp_call_function_many(), > - * etc, are optimal on UV. > - */ > - flush_tlb_func_local(info); > - > - cpumask = uv_flush_tlb_others(cpumask, info); > - if (cpumask) > - smp_call_function_many(cpumask, flush_tlb_func_remote, > - (void *)info, 1); > - return; > - } > - > /* > * If no page tables were freed, we can skip sending IPIs to > * CPUs in lazy TLB mode. They will flush the CPU themselves > -- > 2.17.1 > >
