lkml.org 
[lkml]   [2021]   [Feb]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v5 4/8] x86/mm/tlb: Flush remote and local TLBs concurrently
Date
> On Feb 16, 2021, at 4:10 AM, Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Tue, Feb 09, 2021 at 02:16:49PM -0800, Nadav Amit wrote:
>> @@ -816,8 +821,8 @@ STATIC_NOPV void native_flush_tlb_others(const struct cpumask *cpumask,
>> * doing a speculative memory access.
>> */
>> if (info->freed_tables) {
>> - smp_call_function_many(cpumask, flush_tlb_func,
>> - (void *)info, 1);
>> + on_each_cpu_cond_mask(NULL, flush_tlb_func, (void *)info, true,
>> + cpumask);
>> } else {
>> /*
>> * Although we could have used on_each_cpu_cond_mask(),
>> @@ -844,14 +849,15 @@ STATIC_NOPV void native_flush_tlb_others(const struct cpumask *cpumask,
>> if (tlb_is_not_lazy(cpu))
>> __cpumask_set_cpu(cpu, cond_cpumask);
>> }
>> - smp_call_function_many(cond_cpumask, flush_tlb_func, (void *)info, 1);
>> + on_each_cpu_cond_mask(NULL, flush_tlb_func, (void *)info, true,
>> + cpumask);
>> }
>> }
>
> Surely on_each_cpu_mask() is more appropriate? There the compiler can do
> the NULL propagation because it's on the same TU.
>
> --- a/arch/x86/mm/tlb.c
> +++ b/arch/x86/mm/tlb.c
> @@ -821,8 +821,7 @@ STATIC_NOPV void native_flush_tlb_multi(
> * doing a speculative memory access.
> */
> if (info->freed_tables) {
> - on_each_cpu_cond_mask(NULL, flush_tlb_func, (void *)info, true,
> - cpumask);
> + on_each_cpu_mask(cpumask, flush_tlb_func, (void *)info, true);
> } else {
> /*
> * Although we could have used on_each_cpu_cond_mask(),
> @@ -849,8 +848,7 @@ STATIC_NOPV void native_flush_tlb_multi(
> if (tlb_is_not_lazy(cpu))
> __cpumask_set_cpu(cpu, cond_cpumask);
> }
> - on_each_cpu_cond_mask(NULL, flush_tlb_func, (void *)info, true,
> - cpumask);
> + on_each_cpu_mask(cpumask, flush_tlb_func, (void *)info, true);
> }
> }

Indeed, and there is actually an additional bug - I used cpumask in the
second on_each_cpu_cond_mask() instead of cond_cpumask.

\
 
 \ /
  Last update: 2021-02-17 11:38    [W:0.043 / U:1.188 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site