From: Zhu Yi <yi.zhu@intel.com>
To: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>,
"linville@tuxdriver.com" <linville@tuxdriver.com>,
"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH 1/2] mac80211: support paged rx SKBs
Date: Fri, 26 Mar 2010 11:37:51 +0800 [thread overview]
Message-ID: <1269574671.4043.189.camel@debian> (raw)
In-Reply-To: <20100325072627.GA2562@dhcp-lab-161.englab.brq.redhat.com>
On Thu, 2010-03-25 at 15:26 +0800, Stanislaw Gruszka wrote:
>
> But wait, isn't that all just workaround for bad performing allocator,
> what should be fixed in proper place not in mac80211 nor iwlwifi. What
> for exactly this is needed, concretes please - that is not described
> in patch changelog.
If a devices is capable of DMA a frame to/from physically discontinuous
host memory, the paged SKB handling can mitigate memory subsystem
pressure for large chunk of continuous memory allocation and also avoid
CPU cycles for memcpy. In Linux kernel, since TCP/IP stacks and
(capable) devices support paged SKBs, mac80211 will become the
bottleneck if it still couldn't provide the support. For devices don't
support paged SKBs, this patch doesn't bring performance issues. So it
should be a good thing to have for us.
Thanks,
-yi
next prev parent reply other threads:[~2010-03-26 3:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-24 2:57 [PATCH 1/2] mac80211: support paged rx SKBs Zhu Yi
2010-03-24 2:57 ` [PATCH 2/2] iwlwifi: remove skb_linearize for rx frames Zhu Yi
2010-03-24 5:49 ` [PATCH 1/2] mac80211: support paged rx SKBs Johannes Berg
2010-03-24 13:00 ` Stanislaw Gruszka
2010-03-24 16:16 ` Johannes Berg
2010-03-25 7:26 ` Stanislaw Gruszka
2010-03-26 3:37 ` Zhu Yi [this message]
2010-03-25 6:33 ` Kalle Valo
2010-03-26 3:57 ` Zhu Yi
2010-03-26 6:15 ` Kalle Valo
2010-03-26 8:03 ` Zhu Yi
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=1269574671.4043.189.camel@debian \
--to=yi.zhu@intel.com \
--cc=johannes@sipsolutions.net \
--cc=linux-wireless@vger.kernel.org \
--cc=linville@tuxdriver.com \
--cc=sgruszka@redhat.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).