From: Bart Van Assche <bvanassche@acm.org>
To: dgilbert@interlog.com,
SCSI development list <linux-scsi@vger.kernel.org>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@ORACLE.COM>,
USB list <linux-usb@vger.kernel.org>
Subject: Re: lib/scatterlist.c : sgl_alloc_order promises more than it delivers
Date: Sun, 11 Oct 2020 15:24:34 -0700 [thread overview]
Message-ID: <a9a2a37a-218b-a75d-103d-d15194e2e020@acm.org> (raw)
In-Reply-To: <c4da2372-2957-5ad1-1433-f5d5b6e6b85d@interlog.com>
On 10/11/20 2:21 PM, Douglas Gilbert wrote:
> My testing suggests using a store built with sgl_alloc_order() *** is a
> little faster but with a lower standard deviation (i.e. spread) on timings
> from repeated tests.
sgl_alloc_order() supports allocating SG-lists with higher order pages.
Allocating such S/G-lists is a workaround for the segment count limitations
of some DMA engines. Are you perhaps using sgl_alloc_order() for allocating
long-living data buffers? sgl_alloc_order() was not intended to be used for
that purpose. Anyway, if your use case can be implemented without introducing
any drawbacks for other users, feel free to submit a patch.
Thanks,
Bart.
prev parent reply other threads:[~2020-10-11 22:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-25 1:46 lib/scatterlist.c : sgl_alloc_order promises more than it delivers Douglas Gilbert
2020-09-25 2:34 ` Bart Van Assche
2020-09-25 4:55 ` Douglas Gilbert
2020-09-26 4:32 ` Bart Van Assche
2020-10-11 21:21 ` Douglas Gilbert
2020-10-11 22:24 ` Bart Van Assche [this message]
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=a9a2a37a-218b-a75d-103d-d15194e2e020@acm.org \
--to=bvanassche@acm.org \
--cc=dgilbert@interlog.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=martin.petersen@ORACLE.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).