lkml.org 
[lkml]   [2024]   [Apr]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mm: Always sanity check anon_vma first for per-vma locks
On Wed, Apr 10, 2024 at 05:23:18PM -0400, Peter Xu wrote:
> On Wed, Apr 10, 2024 at 10:10:45PM +0100, Matthew Wilcox wrote:
> > > I can do some tests later today or tomorrow. Any suggestion you have on
> > > amplifying such effect that you have concern with?
> >
> > 8 socket NUMA system, 800MB text segment, 10,000 threads. No, I'm not
> > joking, that's a real customer workload.
>
> Well, I believe you, but even with this, that's a total of 800MB memory on
> a giant moster system... probably just to fault in once.
>
> And even before we talk about that into details.. we're talking about such
> giant program running acorss hundreds of cores with hundreds of MB text,
> then... hasn't the program developer already considered mlockall() at the
> entry of the program? Wouldn't that greatly beneficial already with
> whatever granule of locks that a future fault would take?

I don't care what your theory is, or even what your benchmarking shows.
I had basically the inverse of this patch, and my customer's workload
showed significant improvement as a result. Data talks, bullshit walks.
Your patch is NAKed and will remain NAKed.

\
 
 \ /
  Last update: 2024-05-27 16:33    [W:0.125 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site