From: Josef Bacik <josef@toxicpanda.com>
To: "René Rebe" <rene@exactcode.de>, linux-btrfs@vger.kernel.org
Subject: Re: [BUG] 500-2000% performance regression w/ 5.10
Date: Tue, 22 Dec 2020 22:14:36 -0500 [thread overview]
Message-ID: <862a1a08-2567-e923-4df2-b2e4fe82f99b@toxicpanda.com> (raw)
In-Reply-To: <B4BB2DCB-C438-4871-9DDD-D6FB0E6E4F1B@exactcode.de>
On 12/21/20 2:45 PM, René Rebe wrote:
> Hey there,
>
> as a long time btrfs user I noticed some some things became very slow
> w/ Linux kernel 5.10. I found a very simple test case, namely extracting
> a huge tarball like:
>
> tar xf /usr/src/t2-clean/download/mirror/f/firefox-84.0.source.tar.zst
>
> Why my external, USB3 road-warrior SSD on a Ryzen 5950x this
> went from ~15 seconds w/ 5.9 to nearly 5 minutes in 5.10, or 2000%
>
> To rule out USB, I also tested a brand new PCIe 4.0 SSD, with
> a similar, albeit not as shocking regression from 5.2 seconds
> to ~34 seconds or∫~650%.
>
> Somehow testing that in a VM did over virtio did not produce
> as different results, although it was already 35 seconds slow
> with 5.9.
>
> # first bad commit: [38d715f494f2f1dddbf3d0c6e50aefff49519232]
> btrfs: use btrfs_start_delalloc_roots in shrink_delalloc
>
Eesh that's not great, I'll work it out in the morning, thanks,
Josef
next prev parent reply other threads:[~2020-12-23 3:15 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-21 19:45 [BUG] 500-2000% performance regression w/ 5.10 René Rebe
2020-12-22 8:28 ` Qu Wenruo
2020-12-22 9:12 ` Rene Rebe
2020-12-23 3:14 ` Josef Bacik [this message]
2020-12-23 19:41 ` Josef Bacik
2020-12-23 20:31 ` Holger Hoffstätte
2020-12-23 20:34 ` Josef Bacik
2020-12-24 18:09 ` Josef Bacik
2020-12-24 21:11 ` René Rebe
2020-12-26 12:24 ` Nikolay Borisov
2020-12-26 15:30 ` Rene Rebe
2020-12-26 12:23 ` Nikolay Borisov
2021-01-04 1:15 ` Chris Murphy
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