From: "Leon Woestenberg" <leon.woestenberg@gmail.com>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: scatterlist.c or dma_map_sg() should coalesce?
Date: Sun, 28 Sep 2008 17:47:59 +0200 [thread overview]
Message-ID: <c384c5ea0809280847p6a7d2e9as1b2454142751a468@mail.gmail.com> (raw)
Hello,
in 2.6.27+, if I want to create a scatterlist of a large buffer in
virtual memory in a device driver, can I expect the scatterlist and/or
mapping API to provide me with a minimal list, each entry describing a
maximum bus-contiguous piece of memory? (i.e. can I assume coalescing
is done for me?).
In 2.6.24, dma_map_sg() *may* coalesce, but doesn't do so for my
platform, so for optimal DMA transfers the device driver needs to
coalesce the list entries.
Regards,
--
Leon
next reply other threads:[~2008-09-28 15:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-28 15:47 Leon Woestenberg [this message]
2008-09-28 17:11 ` FUJITA Tomonori
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=c384c5ea0809280847p6a7d2e9as1b2454142751a468@mail.gmail.com \
--to=leon.woestenberg@gmail.com \
--cc=linux-kernel@vger.kernel.org \
/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
all inboxes | Powered by JetHome®