From: Christoph Hellwig <hch@lst.de>
To: Wang Yugui <wangyugui@e16-tech.com>
Cc: Christoph Hellwig <hch@lst.de>,
linux-btrfs@vger.kernel.org, Chris Mason <clm@fb.com>
Subject: Re: btrfs write-bandwidth performance regression of 6.5-rc4/rc3
Date: Wed, 2 Aug 2023 11:26:31 +0200 [thread overview]
Message-ID: <20230802092631.GA27963@lst.de> (raw)
In-Reply-To: <20230802080451.F0C2.409509F4@e16-tech.com>
On Wed, Aug 02, 2023 at 08:04:57AM +0800, Wang Yugui wrote:
> > And with only a revert of
> >
> > "btrfs: submit IO synchronously for fast checksum implementations"?
>
> GOOD performance when only (Revert "btrfs: submit IO synchronously for fast
> checksum implementations")
Ok, so you have a case where the offload for the checksumming generation
actually helps (by a lot). Adding Chris to the Cc list as he was
involved with this.
> > > - if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &bbio->fs_info->flags))
> > > + if ((bbio->bio.bi_opf & REQ_META) && test_bit(BTRFS_FS_CSUM_IMPL_FAST, &bbio->fs_info->flags))
> > > return false;
> >
> > This disables synchronous checksum calculation entirely for data I/O.
>
> without this fix, data I/O checksum is always synchronous?
> this is a feature change of "btrfs: submit IO synchronously for fast checksum implementations"?
It is never with the above patch.
>
> > Also I'm curious if you see any differents for a non-RAID0 (i.e.
> > single profile) workload.
>
> '-m single -d single' is about 10% slow that '-m raid1 -d raid0' in this test
> case.
How does it compare with and without the revert? Can you add the numbers?
next prev parent reply other threads:[~2023-08-02 9:26 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-31 7:22 btrfs write-bandwidth performance regression of 6.5-rc4/rc3 Wang Yugui
2023-08-01 2:22 ` Wang Yugui
2023-08-01 8:35 ` Christoph Hellwig
2023-08-01 8:56 ` Wang Yugui
2023-08-01 9:03 ` Christoph Hellwig
2023-08-01 9:32 ` Wang Yugui
2023-08-01 10:00 ` Christoph Hellwig
2023-08-01 13:04 ` Wang Yugui
2023-08-01 14:59 ` Christoph Hellwig
2023-08-01 15:51 ` Wang Yugui
2023-08-01 15:56 ` Christoph Hellwig
2023-08-01 15:57 ` Christoph Hellwig
2023-08-02 0:04 ` Wang Yugui
2023-08-02 9:26 ` Christoph Hellwig [this message]
2023-08-11 8:58 ` Linux regression tracking (Thorsten Leemhuis)
2023-08-11 10:31 ` Christoph Hellwig
2023-08-11 14:23 ` Wang Yugui
2023-08-11 14:52 ` Chris Mason
2023-08-13 9:50 ` Wang Yugui
2023-08-29 9:45 ` Linux regression tracking (Thorsten Leemhuis)
2023-09-11 7:02 ` Thorsten Leemhuis
2023-09-11 23:20 ` Wang Yugui
2023-09-12 7:58 ` Linux regression tracking (Thorsten Leemhuis)
2023-09-26 10:55 ` Thorsten Leemhuis
2023-09-26 17:18 ` Chris Mason
2023-09-27 11:30 ` Linux regression tracking (Thorsten Leemhuis)
2023-12-06 14:22 ` Linux regression tracking (Thorsten Leemhuis)
2023-12-13 15:57 ` Naohiro Aota
2023-08-02 8:45 ` Linux regression tracking #adding (Thorsten Leemhuis)
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