From: Jens Axboe <axboe@fb.com>
To: Richard Weinberger <richard@nod.at>,
Ezequiel Garcia <ezequiel.garcia@free-electrons.com>,
<hch@infradead.org>, <dedekind1@gmail.com>
Cc: linux-mtd@lists.infradead.org, computersforpeace@gmail.com,
dwmw2@infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] UBI: Block: Add blk-mq support
Date: Sun, 2 Nov 2014 18:20:39 -0700 [thread overview]
Message-ID: <5456D867.5020303@fb.com> (raw)
In-Reply-To: <5456B4F8.1000608@nod.at>
On 2014-11-02 15:49, Richard Weinberger wrote:
> AFAICT blk-mq allocates one struct ubiblock_pdu per device.
> As all IO is done via scattergather the memory footprint should be good.
> But I'm sure Christoph can tell you the glory details.
That is true, the request list and pdu is allocated upfront. If that is
a problem, the pdu need not be allocated upfront but could be done at IO
time instead. With that comes a bit more complicated retry handling, for
memory shortage situations.
--
Jens Axboe
WARNING: multiple messages have this Message-ID (diff)
From: Jens Axboe <axboe@fb.com>
To: Richard Weinberger <richard@nod.at>,
Ezequiel Garcia <ezequiel.garcia@free-electrons.com>,
<hch@infradead.org>, <dedekind1@gmail.com>
Cc: <dwmw2@infradead.org>, <computersforpeace@gmail.com>,
<linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] UBI: Block: Add blk-mq support
Date: Sun, 2 Nov 2014 18:20:39 -0700 [thread overview]
Message-ID: <5456D867.5020303@fb.com> (raw)
In-Reply-To: <5456B4F8.1000608@nod.at>
On 2014-11-02 15:49, Richard Weinberger wrote:
> AFAICT blk-mq allocates one struct ubiblock_pdu per device.
> As all IO is done via scattergather the memory footprint should be good.
> But I'm sure Christoph can tell you the glory details.
That is true, the request list and pdu is allocated upfront. If that is
a problem, the pdu need not be allocated upfront but could be done at IO
time instead. With that comes a bit more complicated retry handling, for
memory shortage situations.
--
Jens Axboe
next prev parent reply other threads:[~2014-11-03 1:20 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-02 13:00 [PATCH] UBI: Block: Add blk-mq support Richard Weinberger
2014-11-02 13:00 ` Richard Weinberger
2014-11-02 21:52 ` Ezequiel Garcia
2014-11-02 21:52 ` Ezequiel Garcia
2014-11-02 22:21 ` Richard Weinberger
2014-11-02 22:21 ` Richard Weinberger
2014-11-02 22:27 ` Ezequiel Garcia
2014-11-02 22:27 ` Ezequiel Garcia
2014-11-02 22:49 ` Richard Weinberger
2014-11-02 22:49 ` Richard Weinberger
2014-11-03 1:20 ` Jens Axboe [this message]
2014-11-03 1:20 ` Jens Axboe
2014-11-03 1:18 ` Jens Axboe
2014-11-03 1:18 ` Jens Axboe
2014-11-03 5:03 ` Ming Lei
2014-11-03 5:03 ` Ming Lei
2014-11-03 13:58 ` Ezequiel Garcia
2014-11-03 13:58 ` Ezequiel Garcia
2014-11-03 18:22 ` Richard Weinberger
2014-11-03 18:22 ` Richard Weinberger
2014-11-03 8:18 ` Christoph Hellwig
2014-11-03 8:18 ` Christoph Hellwig
2014-11-03 8:23 ` Richard Weinberger
2014-11-03 8:23 ` Richard Weinberger
2014-11-07 9:46 ` Artem Bityutskiy
2014-11-07 9:46 ` Artem Bityutskiy
2014-11-07 9:53 ` Richard Weinberger
2014-11-07 9:53 ` Richard Weinberger
2014-11-07 9:56 ` Artem Bityutskiy
2014-11-07 9:56 ` Artem Bityutskiy
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=5456D867.5020303@fb.com \
--to=axboe@fb.com \
--cc=computersforpeace@gmail.com \
--cc=dedekind1@gmail.com \
--cc=dwmw2@infradead.org \
--cc=ezequiel.garcia@free-electrons.com \
--cc=hch@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=richard@nod.at \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.