lkml.org 
[lkml]   [2012]   [May]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/3] x86/flush_tlb: try flush_tlb_single one by one in flush_tlb_range
On 05/02/2012 09:44 PM, Borislav Petkov wrote:

> On Wed, May 02, 2012 at 07:38:47PM +0800, Alex Shi wrote:
>>> Are you saying you want to have this setting per family?
>>
>> Set it according to CPU type is more precise, but looks ugly.
>
> By "CPU type" do you mean microarchitecture here?


Yes.

>
>> I am wondering if it worth to do. Maybe conservative selection is
>> acceptable?
>
> Well, as I said earlier, I'd run it on a couple of different machines
> and make FLUSHALL_BAR configurable from userspace - this way you have
> real, solid data instead of guessing the exact number.


Consider different CPU type has different balance point, I has another
patch will add a interface for tuning.

>
>>> Also, have you run your patches with other benchmarks beside your
>>> microbenchmark, say kernbench, SPEC<something>, i.e. some other
>>> multithreaded benchmark touching shared memory? Are you seeing any
>>> improvement there?
>>
>> I tested oltp reading and specjbb2005 with openjdk. They should not much
>> flush_tlb_range calling. So, no clear improvement.
>> Do you know benchmarks which cause enough flush_tlb_range?
>
> Not really. Probably get a couple of benchmarks and count
> flush_tlb_range calls with trace_printk or perf probe? :-)


perf probe is enough. :)


\
 
 \ /
  Last update: 2012-05-03 11:41    [W:0.073 / U:0.916 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site