lkml.org 
[lkml]   [2021]   [Oct]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] mm: move more expensive part of XA setup out of mapping check
From
Date
On 10/26/21 12:08 PM, Matthew Wilcox wrote:
> On Tue, Oct 26, 2021 at 10:01:20AM -0600, Jens Axboe wrote:
>> The fast path here is not needing any writeback, yet we spend time setting
>> up the xarray lookup data upfront. Move the part that actually needs to
>> iterate the address space mapping into a separate helper, saving ~30% of
>> the time here.
>
> No objection to this patch, but it did remind me that I never saw an answer to
> https://lore.kernel.org/all/CAHk-=wg_-EwefQ_3Osz4iJxTrTk3tfrV53Z7-jaGg=tm9i5TXg@mail.gmail.com/
> (and nor did lore)

Totally missed that, and yes there could be cases where that lookup is
going to be way too slow. I'll take a look.

--
Jens Axboe

\
 
 \ /
  Last update: 2021-10-26 20:12    [W:0.025 / U:1.676 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site