From: Stanislaw Gruszka <sgruszka@redhat.com>
To: "Vladislav Zolotarov" <vladz@broadcom.com>
Cc: "David Miller" <davem@davemloft.net>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"Eilon Greenstein" <eilong@broadcom.com>,
"dhowells@redhat.com" <dhowells@redhat.com>
Subject: Re: [RFC PATCH] bnx2x: fix tx queue locking and memory barriers
Date: Thu, 25 Feb 2010 17:03:08 +0100 [thread overview]
Message-ID: <20100225170308.6294aa1a@dhcp-lab-109.englab.brq.redhat.com> (raw)
In-Reply-To: <8628FE4E7912BF47A96AE7DD7BAC0AADCB46A2ADC5@SJEXCHCCR02.corp.ad.broadcom.com>
On Thu, 25 Feb 2010 07:49:48 -0800
"Vladislav Zolotarov" <vladz@broadcom.com> wrote:
> In bnx2x_start_xmit(): right after the "stop queue" there is an smp_mb(), which will bring the cpu0 cache and a fresh fp->tx_bd_cons value to cpu1 and the following if() will return true and the queue will be released from bnx2x_start_xmit() flow.
If I understand correctly what is written in Documentation/memory-barriers.txt
this smp_mb() need to have another "paired" smp_{w}mb() on cpu0 to make value
be updated on cpu1, which is missing.
next prev parent reply other threads:[~2010-02-25 16:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-25 13:08 [RFC PATCH] bnx2x: fix tx queue locking and memory barriers Stanislaw Gruszka
2010-02-25 10:18 ` David Miller
2010-02-25 15:40 ` Stanislaw Gruszka
2010-02-25 15:49 ` Vladislav Zolotarov
2010-02-25 16:03 ` Stanislaw Gruszka [this message]
2010-02-25 16:06 ` David Miller
2010-02-25 16:16 ` Stanislaw Gruszka
2010-02-25 16:14 ` Vladislav Zolotarov
2010-02-25 13:28 ` Vladislav Zolotarov
2010-03-10 17:09 ` David Howells
2010-03-10 17:49 ` David Miller
2010-03-10 18:32 ` David Howells
2010-03-11 13:10 ` Stanislaw Gruszka
2010-03-10 17:19 ` David Howells
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=20100225170308.6294aa1a@dhcp-lab-109.englab.brq.redhat.com \
--to=sgruszka@redhat.com \
--cc=davem@davemloft.net \
--cc=dhowells@redhat.com \
--cc=eilong@broadcom.com \
--cc=netdev@vger.kernel.org \
--cc=vladz@broadcom.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).