lkml.org 
[lkml]   [2019]   [Dec]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 05/17] asm-generic/tlb: Rename HAVE_RCU_TABLE_NO_INVALIDATE
From
Date
On 12/16/19 6:50 PM, Peter Zijlstra wrote:
> On Mon, Dec 16, 2019 at 06:43:53PM +0530, Aneesh Kumar K.V wrote:
>> On 12/16/19 6:07 PM, Peter Zijlstra wrote:
>
>>> I'm confused, are you saing you're happy to have PowerPC eat the extra
>>> TLB invalidates? I thought you cared about PPC performance :-)
>>>
>>>
>>
>> Instead can we do
>>
>> static inline void tlb_table_invalidate(struct mmu_gather *tlb)
>> {
>> #ifndef CONFIG_MMU_GATHER_RCU_TABLE_FREE
>> * Invalidate page-table caches used by hardware walkers. Then we still
>> * need to RCU-sched wait while freeing the pages because software
>> * walkers can still be in-flight.
>> */
>> tlb_flush_mmu_tlbonly(tlb);
>> #endif
>> }
>
> How does that not break ARM/ARM64/s390 and x86 ?
>

Hmm I missed that usage of RCU_TABLE_NO_INVALIDATE.

Ok I guess we need to revert this change that went upstream this merge
window then

commit 52162ec784fa05f3a4b1d8e84421279998be3773
Author: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Date: Thu Oct 24 13:28:00 2019 +0530

powerpc/mm/book3s64/radix: Use freed_tables instead of need_flush_all



I will review the change closely.

-aneesh

\
 
 \ /
  Last update: 2019-12-16 14:42    [W:0.056 / U:1.220 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site