Re: [RFC PATCH] mm: avoid access flag update TLB flush for retried page fault

2020-07-08 Thread Yang Shi
On 7/8/20 10:29 AM, Catalin Marinas wrote: On Wed, Jul 08, 2020 at 09:40:11AM -0700, Yang Shi wrote: On 7/8/20 1:00 AM, Will Deacon wrote: On Wed, Jul 08, 2020 at 02:54:32AM +0800, Yang Shi wrote: Recently we found regression when running will_it_scale/page_fault3 test on ARM64. Over 70% d

Re: [RFC PATCH] mm: avoid access flag update TLB flush for retried page fault

2020-07-08 Thread Catalin Marinas
On Wed, Jul 08, 2020 at 09:40:11AM -0700, Yang Shi wrote: > On 7/8/20 1:00 AM, Will Deacon wrote: > > On Wed, Jul 08, 2020 at 02:54:32AM +0800, Yang Shi wrote: > > > Recently we found regression when running will_it_scale/page_fault3 test > > > on ARM64. Over 70% down for the multi processes cases

Re: [RFC PATCH] mm: avoid access flag update TLB flush for retried page fault

2020-07-08 Thread Yang Shi
On 7/8/20 1:00 AM, Will Deacon wrote: On Wed, Jul 08, 2020 at 02:54:32AM +0800, Yang Shi wrote: Recently we found regression when running will_it_scale/page_fault3 test on ARM64. Over 70% down for the multi processes cases and over 20% down for the multi threads cases. It turns out the regr

Re: [RFC PATCH] mm: avoid access flag update TLB flush for retried page fault

2020-07-08 Thread Will Deacon
On Wed, Jul 08, 2020 at 02:54:32AM +0800, Yang Shi wrote: > Recently we found regression when running will_it_scale/page_fault3 test > on ARM64. Over 70% down for the multi processes cases and over 20% down > for the multi threads cases. It turns out the regression is caused by commit > 89b15332a

[RFC PATCH] mm: avoid access flag update TLB flush for retried page fault

2020-07-07 Thread Yang Shi
Recently we found regression when running will_it_scale/page_fault3 test on ARM64. Over 70% down for the multi processes cases and over 20% down for the multi threads cases. It turns out the regression is caused by commit 89b15332af7c0312a41e50846819ca6613b58b4c ("mm: drop mmap_sem before calling