linux-kernel - Re: [PATCH 1/1] dm-ioband: I/O bandwidth controller

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20090519.174352.71107893.ryov@valinux.co.jp>
Date:	Tue, 19 May 2009 17:43:52 +0900 (JST)
From:	Ryo Tsuruta <ryov@...inux.co.jp>
To:	vgoyal@...hat.com
Cc:	linux-kernel@...r.kernel.org, dm-devel@...hat.com,
	containers@...ts.linux-foundation.org,
	virtualization@...ts.linux-foundation.org,
	xen-devel@...ts.xensource.com
Subject: Re: [PATCH 1/1] dm-ioband: I/O bandwidth controller

Hi Vivek,

From: Ryo Tsuruta <ryov@...inux.co.jp>
Subject: [PATCH 1/1] dm-ioband: I/O bandwidth controller
Date: Tue, 19 May 2009 17:39:28 +0900 (JST)

> Hi Alasdair and all,
> 
> This is the dm-ioband version 1.11.0 release. This patch can be
> applied cleanly to current agk's tree. Alasdair, please give some
> comments and suggestions.
> 
> Changes from the previous release:
> - Classify IOs in sync/async instead of read/write since the IO
>   request allocation/congestion logic were changed to be sync/async
>   based.
> - IOs belong to the real-time class are dispatched in preference to
>   other IOs, regardless of the assigned bandwidth.

I ran your script from the following URL to see IOs belong to the
real-time class take precedence.
http://linux.derkeiler.com/Mailing-Lists/Kernel/2009-04/msg08355.html

    Script
    ======
    # /dev/mapper/ioband1 is mounted on /mnt1
    rm /mnt1/aggressivewriter
    sync
    echo 3 > /proc/sys/vm/drop_caches
    # launch an hostile writer
    ionice -c2 -n7 dd if=/dev/zero of=/mnt1/aggressivewriter \
       bs=4K count=524288 conv=fdatasync &
    # Reader
    ionice -c1 -n0 dd if=/mnt1/testzerofile1 of=/dev/null &
    wait $!
    echo "reader finished"

    old dm-ioband
    =============
    First run
    2147483648 bytes (2.1 GB) copied, 100.343 seconds, 21.4 MB/s (Reader)
    reader finished
    2147483648 bytes (2.1 GB) copied, 101.107 seconds, 21.2 MB/s (Writer)

    new dm-ioband v1.11.0
    =====================
    First run
    2147483648 bytes (2.1 GB) copied, 35.0623 seconds, 61.2 MB/s (Reader)
    reader finished
    2147483648 bytes (2.1 GB) copied, 87.6979 seconds, 24.5 MB/s (Writer)

The RT reader took precedence over the aggressive writer, regardless
of assigned bandwidth. However, I think that some sort of limitation
for RT IOs is needed. What do you think?

Thanks,
Ryo Tsuruta
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/