From: Jens Axboe <axboe@kernel.dk>
To: "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>,
linux-block@vger.kernel.org, Dexuan Cui <decui@microsoft.com>,
ming.lei@redhat.com, hch@lst.de, Long Li <longli@microsoft.com>,
"Michael Kelley (LINUX)" <mikelley@microsoft.com>,
linux-kernel@vger.kernel.org
Subject: Re: very low IOPS due to "block: reduce kblockd_mod_delayed_work_on() CPU consumption"
Date: Sat, 18 Dec 2021 12:02:38 -0700 [thread overview]
Message-ID: <7d1e4bb8-1a73-9529-3191-66df4ff2d5fe@kernel.dk> (raw)
In-Reply-To: <1639853092.524jxfaem2.none@localhost>
On 12/18/21 11:57 AM, Alex Xu (Hello71) wrote:
> Hi,
>
> I recently noticed that between 6441998e2e and 9eaa88c703, I/O became
> much slower on my machine using ext4 on dm-crypt on NVMe with bfq
> scheduler. Checking iostat during heavy usage (find / -xdev and fstrim
> -v /), maximum IOPS had fallen from ~10000 to ~100. Reverting cb2ac2912a
> ("block: reduce kblockd_mod_delayed_work_on() CPU consumption") resolves
> the issue.
Hmm interesting. I'll try and see if I can reproduce this and come up
with a fix.
--
Jens Axboe
next prev parent reply other threads:[~2021-12-18 19:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1639853092.524jxfaem2.none.ref@localhost>
2021-12-18 18:57 ` very low IOPS due to "block: reduce kblockd_mod_delayed_work_on() CPU consumption" Alex Xu (Hello71)
2021-12-18 19:02 ` Jens Axboe [this message]
2021-12-19 14:58 ` Jens Axboe
2021-12-19 15:28 ` Jens Axboe
2021-12-20 5:15 ` Dexuan Cui
2021-12-28 2:30 ` Yin Fengwei
[not found] ` <20211228134926.GA31268@xsang-OptiPlex-9020>
2022-01-22 6:14 ` Dexuan Cui
2022-02-08 18:34 ` Dexuan Cui
2021-12-23 11:50 ` Christoph Hellwig
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