lkml.org 
[lkml]   [2020]   [May]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH 0/7] mm: Get rid of vmalloc_sync_(un)mappings()
On Mon, May 11, 2020 at 08:52:04AM -0700, Matthew Wilcox wrote:
> On Mon, May 11, 2020 at 09:31:34AM +0200, Peter Zijlstra wrote:
> > On Sat, May 09, 2020 at 06:11:57PM -0700, Matthew Wilcox wrote:
> > > Iterating an XArray (whether the entire thing
> > > or with marks) is RCU-safe and faster than iterating a linked list,
> > > so this should solve the problem?
> >
> > It can hardly be faster if you want all elements -- which is I think the
> > case here. We only call into this if we change an entry, and then we
> > need to propagate that change to all.
>
> Of course it can be faster. Iterating an array is faster than iterating
> a linked list because caches. While an XArray is a segmented array
> (so slower than a plain array), it's plainly going to be faster than
> iterating a linked list.

Fair enough, mostly also because the actual work (setting a single PTE)
doesn't dominate in this case.

\
 
 \ /
  Last update: 2020-05-11 19:03    [W:0.080 / U:0.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site