linux-kernel - Re: [PATCH v3 00/20] Virtual Swap Space

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Message-ID: <CAKEwX=OYauRgQoj7cxznpROknHt9NsKLOmkvaFtkEh8T1KASag@mail.gmail.com>
Date: Tue, 10 Feb 2026 11:23:27 -0800
From: Nhat Pham <nphamcs@...il.com>
To: Kairui Song <ryncsn@...il.com>
Cc: linux-mm@...ck.org, akpm@...ux-foundation.org, hannes@...xchg.org, 
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Subject: Re: [PATCH v3 00/20] Virtual Swap Space

On Tue, Feb 10, 2026 at 11:11 AM Nhat Pham <nphamcs@...il.com> wrote:
>>
> Hmm this one I don't think I can reproduce without your laptop ;)
>
> Jokes aside, I did try to run the kernel build with disk swapping, and
> the performance is on par with baseline. Swap performance with NVME
> swap tends to be dominated by IO work in my experiments. Do you think
> I missed something here? Maybe it's the concurrency difference (since
> I always run with -j$(nproc), i.e the number of workers == the number
> of processors).

Ah I just noticed that your numbers include only systime. Ignore my IO
comments then.

(I still think in real production system, with disk swapping enabled,
then IO wait time is going to be really important. If you're going to
use disk swap, then this affects real time just as much if not more
than kernel CPU overhead).