From: Jan Kara <jack@suse.cz>
To: Dave Chinner <david@fromorbit.com>
Cc: Kanchan Joshi <joshi.k@samsung.com>,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org,
linux-ext4@vger.kernel.org, axboe@fb.com, prakash.v@samsung.com,
anshul@samsung.com, joshiiitr@gmail.com
Subject: Re: [PATCH v3 3/7] block: add write-hint to stream-id conversion
Date: Tue, 2 Apr 2019 11:20:44 +0200 [thread overview]
Message-ID: <20190402092044.GE12133@quack2.suse.cz> (raw)
In-Reply-To: <20190401050821.GQ23020@dastard>
On Mon 01-04-19 16:08:21, Dave Chinner wrote:
> On Fri, Mar 29, 2019 at 01:23:48PM +0530, Kanchan Joshi wrote:
> > + if(streamid > nr_streams)
> > + streamid = 0;
>
> So, basically, we'll compress all the kernel hints down to "no hint"
> if there are more user streams than the device supports?
>
> Surely we should be reserving a stream for the kernel hints separate
> from the user and "none" streams when we have limited device streams
> available...
The question is what to do in a situation when the device has exactly as
many hints as we currently offer to userspace. Because currently either the
device has enough hints for all userspace hint values or we disable the
feature altogether. If we always mandated some hints are available for the
kernel, we'd have to regress some fuctionality currently available to
userspace. So I think that the option that the kernel won't get any hints
is the least painful solution. Later when people would like to extend hints
available to userspace, we could make sure kernel's batch of hints has
priority over these "extended userspace hints".
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2019-04-02 9:20 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20190329075737epcas1p4f32cad26279c1146982a6c91b3378eab@epcas1p4.samsung.com>
2019-03-29 7:53 ` [PATCH v3 0/7] Extend write-hint for in-kernel use Kanchan Joshi
[not found] ` <CGME20190329075743epcas1p12f1d290e65ddf84eb74ed94a5ae6eb74@epcas1p1.samsung.com>
2019-03-29 7:53 ` [PATCH v3 1/7] block: extend stream count " Kanchan Joshi
2019-03-30 17:48 ` Andreas Dilger
2019-04-01 5:02 ` Dave Chinner
[not found] ` <CGME20190329075746epcas1p19e5a93c1f593b5fed3f98eddf9159aa5@epcas1p1.samsung.com>
2019-03-29 7:53 ` [PATCH v3 2/7] block: introduce API to register stream information with block layer Kanchan Joshi
[not found] ` <CGME20190329075749epcas2p22b85cbdbb7ccb4f7f3ecf69b84f75dc9@epcas2p2.samsung.com>
2019-03-29 7:53 ` [PATCH v3 3/7] block: add write-hint to stream-id conversion Kanchan Joshi
2019-04-01 5:08 ` Dave Chinner
2019-04-02 9:20 ` Jan Kara [this message]
2019-04-02 20:35 ` Dave Chinner
2019-04-03 9:36 ` Jan Kara
2019-04-03 14:47 ` kanchan
[not found] ` <CGME20190329075753epcas1p16ce37362f83ccb8520a782b845dcb905@epcas1p1.samsung.com>
2019-03-29 7:53 ` [PATCH v3 4/7] nvme: register stream info with block layer Kanchan Joshi
2019-03-29 16:58 ` Heitke, Kenneth
[not found] ` <CGME20190329075755epcas2p2d2670db217ae3519d2c4b93d5e3749d1@epcas2p2.samsung.com>
2019-03-29 7:53 ` [PATCH v3 5/7] fs: introduce APIs to enable sending write-hint with buffer-head Kanchan Joshi
[not found] ` <CGME20190329075758epcas1p335511dcb10bb5592ea72409a1d01e752@epcas1p3.samsung.com>
2019-03-29 7:53 ` [PATCH v3 6/7] fs: introduce write-hint start point for in-kernel hints Kanchan Joshi
2019-04-01 5:12 ` Dave Chinner
2019-04-03 14:30 ` kanchan
[not found] ` <CGME20190329075800epcas2p4731f10eabf7d70dc7096117d161b05a3@epcas2p4.samsung.com>
2019-03-29 7:53 ` [PATCH v3 7/7] fs/ext4,jbd2: add support for passing write-hint with journal Kanchan Joshi
2019-03-30 17:49 ` Andreas Dilger
2019-04-02 9:07 ` Jan Kara
2019-04-03 2:57 ` Martin K. Petersen
2019-04-03 13:42 ` kanchan
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=20190402092044.GE12133@quack2.suse.cz \
--to=jack@suse.cz \
--cc=anshul@samsung.com \
--cc=axboe@fb.com \
--cc=david@fromorbit.com \
--cc=joshi.k@samsung.com \
--cc=joshiiitr@gmail.com \
--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=linux-nvme@lists.infradead.org \
--cc=prakash.v@samsung.com \
/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 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).