LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Paolo Valente <paolo.valente@linaro.org>
To: "Srivatsa S. Bhat" <srivatsa@csail.mit.edu>
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>,
	Jeff Moyer <jmoyer@redhat.com>, Theodore Ts'o <tytso@mit.edu>,
	amakhalov@vmware.com, anishs@vmware.com, srivatsab@vmware.com,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Linus Walleij <linus.walleij@linaro.org>
Subject: Re: CFQ idling kills I/O performance on ext4 with blkio cgroup controller
Date: Thu, 13 Jun 2019 07:46:12 +0200	[thread overview]
Message-ID: <43486E4F-2237-4E40-BDFE-07CFCCFFFA25@linaro.org> (raw)
In-Reply-To: <7c5e9d11-4a3d-7df4-c1e6-7c95919522ab@csail.mit.edu>

[-- Attachment #1: Type: text/plain, Size: 2348 bytes --]



> Il giorno 12 giu 2019, alle ore 00:34, Srivatsa S. Bhat <srivatsa@csail.mit.edu> ha scritto:
> 
> On 6/2/19 12:04 AM, Srivatsa S. Bhat wrote:
>> On 5/30/19 3:45 AM, Paolo Valente wrote:
>>> 
> [...]
>>> At any rate, since you pointed out that you are interested in
>>> out-of-the-box performance, let me complete the context: in case
>>> low_latency is left set, one gets, in return for this 12% loss,
>>> a) at least 1000% higher responsiveness, e.g., 1000% lower start-up
>>> times of applications under load [1];
>>> b) 500-1000% higher throughput in multi-client server workloads, as I
>>> already pointed out [2].
>>> 
>> 
>> I'm very happy that you could solve the problem without having to
>> compromise on any of the performance characteristics/features of BFQ!
>> 
>> 
>>> I'm going to prepare complete patches.  In addition, if ok for you,
>>> I'll report these results on the bug you created.  Then I guess we can
>>> close it.
>>> 
>> 
>> Sounds great!
>> 
> 
> Hi Paolo,
> 

Hi

> Hope you are doing great!
> 

Sort of, thanks :)

> I was wondering if you got a chance to post these patches to LKML for
> review and inclusion... (No hurry, of course!)
> 


I'm having troubles testing these new patches on 5.2-rc4.  As it
happened with the first release candidates for 5.1, the CPU of my test
machine (Intel Core i7-2760QM@2.40GHz) is so slowed down that results
are heavily distorted with every I/O scheduler.

Unfortunately, I'm not competent enough to spot the cause of this
regression in a feasible amount of time.  I hope it'll go away with
next release candidates, or I'll test on 5.1.

> Also, since your fixes address the performance issues in BFQ, do you
> have any thoughts on whether they can be adapted to CFQ as well, to
> benefit the older stable kernels that still support CFQ?
> 

I have implanted my fixes on the existing throughput-boosting
infrastructure of BFQ.  CFQ doesn't have such an infrastructure.

If you need I/O control with older kernels, you may want to check my
version of BFQ for legacy block, named bfq-sq and available in this
repo:
https://github.com/Algodev-github/bfq-mq/

I'm willing to provide you with any information or help if needed.

Thanks,
Paolo


> Thank you!
> 
> Regards,
> Srivatsa
> VMware Photon OS


[-- Attachment #2: Message signed with OpenPGP --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

  parent reply	other threads:[~2019-06-13 16:46 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-17 22:16 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
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 [this message]
2019-06-13 19:13                                                 ` Srivatsa S. Bhat
2019-05-23 23:32                           ` Srivatsa S. Bhat
2019-05-30  8:38                             ` Srivatsa S. Bhat

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=43486E4F-2237-4E40-BDFE-07CFCCFFFA25@linaro.org \
    --to=paolo.valente@linaro.org \
    --cc=amakhalov@vmware.com \
    --cc=anishs@vmware.com \
    --cc=axboe@kernel.dk \
    --cc=cgroups@vger.kernel.org \
    --cc=jack@suse.cz \
    --cc=jmoyer@redhat.com \
    --cc=linus.walleij@linaro.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=srivatsa@csail.mit.edu \
    --cc=srivatsab@vmware.com \
    --cc=tytso@mit.edu \
    --cc=ulf.hansson@linaro.org \
    --subject='Re: CFQ idling kills I/O performance on ext4 with blkio cgroup controller' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).