From: Christoph Hellwig <hch@infradead.org>
To: "Holger Hoffstätte" <holger@applied-asynchrony.com>
Cc: Christoph Hellwig <hch@infradead.org>,
linux-block <linux-block@vger.kernel.org>,
martin.petersen@oracle.com
Subject: Re: Block device's sysfs setting getting lost after suspend-resume cycle
Date: Thu, 24 Apr 2025 01:17:17 -0700 [thread overview]
Message-ID: <aAnzjeG9JvMS_atz@infradead.org> (raw)
In-Reply-To: <cacb5382-3352-9835-9774-e7c17b5e93fc@applied-asynchrony.com>
On Wed, Apr 23, 2025 at 07:05:26PM +0200, Holger Hoffstätte wrote:
> There may have been a misunderstanding. I first noticed this on an old
> machine with SATA SSDs where I *do* have an udev rule for readahead.
> I only used my laptop with NVME drive (from ~2021) to reproduce the problem
> and send the email. On that machine I do not have any udev rule to set
> readahead since it's plenty fast.
Ah.
> Not sure if that matters, as it was a valid bug after all and now
> it's fixed, so thanks again!
I usually try to understand what happened to properly document it and
create test cases if needed.
With your above information I dug a bit deeper and found the likely
culprit. Before scsi was converted to the atomic queue limits API, it
did not use the proper blk_queue_io_opt API, so it never updated the
ra_size based on the optimal I/O. Which means the user value did
stick around for SCSI but not the other drivers before.
prev parent reply other threads:[~2025-04-24 8:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-19 10:16 Block device's sysfs setting getting lost after suspend-resume cycle Holger Hoffstätte
2025-04-21 11:49 ` Christoph Hellwig
2025-04-23 6:35 ` Christoph Hellwig
2025-04-23 10:11 ` Holger Hoffstätte
2025-04-23 16:19 ` Christoph Hellwig
2025-04-23 17:05 ` Holger Hoffstätte
2025-04-24 8:17 ` Christoph Hellwig [this message]
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