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Message-Id: <165108909873.140853.15966713411862913960.b4-ty@kernel.dk>
Date: Wed, 27 Apr 2022 13:51:38 -0600
From: Jens Axboe <axboe@...nel.dk>
To: tj@...nel.org
Cc: linux-block@...r.kernel.org, saravanand@...com,
chris.obbard@...labora.com, kernel-team@...com,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH block-5.18] Revert "block: inherit request start time from bio for BLK_CGROUP"
On Wed, 27 Apr 2022 09:49:12 -1000, Tejun Heo wrote:
> This reverts commit 0006707723233cb2a9a23ca19fc3d0864835704c. It has a
> couple problems:
>
> * bio_issue_time() is stored in bio->bi_issue truncated to 51 bits. This
> overflows in slightly over 26 days. Setting rq->io_start_time_ns with it
> means that io duration calculation would yield >26days after 26 days of
> uptime. This, for example, confuses kyber making it cause high IO
> latencies.
>
> [...]
Applied, thanks!
[1/1] Revert "block: inherit request start time from bio for BLK_CGROUP"
commit: 4cddeacad6d4b23493a108d0705e7d2ab89ba5a3
Best regards,
--
Jens Axboe
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