From: "Srivatsa S. Bhat" <srivatsa@csail.mit.edu>
To: Paolo Valente <paolo.valente@linaro.org>
Cc: linux-fsdevel@vger.kernel.org,
linux-block <linux-block@vger.kernel.org>,
linux-ext4@vger.kernel.org, cgroups@vger.kernel.org,
kernel list <linux-kernel@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>, Jan Kara <jack@suse.cz>,
jmoyer@redhat.com, Theodore Ts'o <tytso@mit.edu>,
amakhalov@vmware.com, anishs@vmware.com, srivatsab@vmware.com
Subject: Re: CFQ idling kills I/O performance on ext4 with blkio cgroup controller
Date: Tue, 21 May 2019 15:51:46 -0700 [thread overview]
Message-ID: <0e3fdf31-70d9-26eb-7b42-2795d4b03722@csail.mit.edu> (raw)
In-Reply-To: <FC24E25F-4578-454D-AE2B-8D8D352478D8@linaro.org>
[ Resending this mail with a dropbox link to the traces (instead
of a file attachment), since it didn't go through the last time. ]
On 5/21/19 10:38 AM, Paolo Valente wrote:
>
>> So, instead of only sending me a trace, could you please:
>> 1) apply this new patch on top of the one I attached in my previous email
>> 2) repeat your test and report results
>
> One last thing (I swear!): as you can see from my script, I tested the
> case low_latency=0 so far. So please, for the moment, do your test
> with low_latency=0. You find the whole path to this parameter in,
> e.g., my script.
>
No problem! :) Thank you for sharing patches for me to test!
I have good news :) Your patch improves the throughput significantly
when low_latency = 0.
Without any patch:
dd if=/dev/zero of=/root/test.img bs=512 count=10000 oflag=dsync
10000+0 records in
10000+0 records out
5120000 bytes (5.1 MB, 4.9 MiB) copied, 58.0915 s, 88.1 kB/s
With both patches applied:
dd if=/dev/zero of=/root/test0.img bs=512 count=10000 oflag=dsync
10000+0 records in
10000+0 records out
5120000 bytes (5.1 MB, 4.9 MiB) copied, 3.87487 s, 1.3 MB/s
The performance is still not as good as mq-deadline (which achieves
1.6 MB/s), but this is a huge improvement for BFQ nonetheless!
A tarball with the trace output from the 2 scenarios you requested,
one with only the debug patch applied (trace-bfq-add-logs-and-BUG_ONs),
and another with both patches applied (trace-bfq-boost-injection) is
available here:
https://www.dropbox.com/s/pdf07vi7afido7e/bfq-traces.tar.gz?dl=0
Thank you!
Regards,
Srivatsa
VMware Photon OS
next prev parent reply other threads:[~2019-05-21 22:52 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-17 22:16 CFQ idling kills I/O performance on ext4 with blkio cgroup controller Srivatsa S. Bhat
2019-05-18 18:39 ` Paolo Valente
2019-05-18 19:28 ` Theodore Ts'o
2019-05-20 9:15 ` Jan Kara
2019-05-20 10:45 ` Paolo Valente
2019-05-21 16:48 ` Theodore Ts'o
2019-05-21 18:19 ` Josef Bacik
2019-05-21 19:10 ` Theodore Ts'o
2019-05-20 10:38 ` Paolo Valente
2019-05-21 7:38 ` Andrea Righi
2019-05-18 20:50 ` Srivatsa S. Bhat
2019-05-20 10:19 ` Paolo Valente
2019-05-20 22:45 ` Srivatsa S. Bhat
2019-05-21 6:23 ` Paolo Valente
2019-05-21 7:19 ` Srivatsa S. Bhat
2019-05-21 9:10 ` Jan Kara
2019-05-21 16:31 ` Theodore Ts'o
2019-05-21 11:25 ` Paolo Valente
2019-05-21 13:20 ` Paolo Valente
2019-05-21 16:21 ` Paolo Valente
2019-05-21 17:38 ` Paolo Valente
2019-05-21 22:51 ` Srivatsa S. Bhat [this message]
2019-05-22 8:05 ` Paolo Valente
2019-05-22 9:02 ` Srivatsa S. Bhat
2019-05-22 9:12 ` Paolo Valente
2019-05-22 10:02 ` Srivatsa S. Bhat
2019-05-22 9:09 ` Paolo Valente
2019-05-22 10:01 ` Srivatsa S. Bhat
2019-05-22 10:54 ` Paolo Valente
2019-05-23 2:30 ` Srivatsa S. Bhat
2019-05-23 9:19 ` Paolo Valente
2019-05-23 17:22 ` Paolo Valente
2019-05-23 23:43 ` Srivatsa S. Bhat
2019-05-24 6:51 ` Paolo Valente
2019-05-24 7:56 ` Paolo Valente
2019-05-29 1:09 ` Srivatsa S. Bhat
2019-05-29 7:41 ` Paolo Valente
2019-05-30 8:29 ` Srivatsa S. Bhat
2019-05-30 10:45 ` Paolo Valente
2019-06-02 7:04 ` Srivatsa S. Bhat
2019-06-11 22:34 ` Srivatsa S. Bhat
2019-06-12 13:04 ` Jan Kara
2019-06-12 19:36 ` Srivatsa S. Bhat
2019-06-13 6:02 ` Greg Kroah-Hartman
2019-06-13 19:03 ` Srivatsa S. Bhat
2019-06-13 8:20 ` Jan Kara
2019-06-13 19:05 ` Srivatsa S. Bhat
2019-06-13 8:37 ` Jens Axboe
2019-06-13 5:46 ` Paolo Valente
2019-06-13 19:13 ` Srivatsa S. Bhat
2019-05-23 23:32 ` Srivatsa S. Bhat
2019-05-30 8:38 ` Srivatsa S. Bhat
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