From: David Miller <davem@davemloft.net>
To: therbert@google.com
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH v3] net: Allow no-cache copy from user on transmit
Date: Sun, 03 Apr 2011 22:23:41 -0700 (PDT) [thread overview]
Message-ID: <20110403.222341.149838774.davem@davemloft.net> (raw)
In-Reply-To: <20110403.220305.71570981.davem@davemloft.net>
From: David Miller <davem@davemloft.net>
Date: Sun, 03 Apr 2011 22:03:05 -0700 (PDT)
> From: Tom Herbert <therbert@google.com>
> Date: Sun, 3 Apr 2011 21:56:17 -0700 (PDT)
>
>> This patch uses __copy_from_user_nocache on transmit to bypass data
>> cache for a performance improvement. skb_add_data_nocache and
>> skb_copy_to_page_nocache can be called by sendmsg functions to use
>> this feature, initial support is in tcp_sendmsg. This functionality is
>> configurable per device using ethtool.
> ...
>> Signed-off-by: Tom Herbert <therbert@google.com>
>
> Applied, thanks Tom.
Actually, I'm sorry, I have to kick this back to you again Tom.
The original problem is that "linux/uaccess.h" has not been included
in the spot where you try to invoke the nocache copies.
linux/uaccess.h, when ARCH_HAS_NOCACHE_UACCESS is defined, provides
dummy routines.
So it's not correct to use ARCH_HAS_NOCACHE_UACCESS to conditionalize
things in the networking, just make sure linux/uaccess.h is included
at the call sites.
Thanks.
next prev parent reply other threads:[~2011-04-04 5:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-04 4:56 [PATCH v3] net: Allow no-cache copy from user on transmit Tom Herbert
2011-04-04 5:03 ` David Miller
2011-04-04 5:23 ` David Miller [this message]
2011-04-04 15:10 ` Tom Herbert
2011-04-04 16:52 ` David Miller
2011-04-04 19:44 ` Tom Herbert
2011-04-04 20:05 ` David Miller
-- strict thread matches above, loose matches on Subject: below --
2011-03-31 5:04 Tom Herbert
2011-03-31 8:52 ` Michał Mirosław
2011-04-01 4:05 ` Tom Herbert
2011-04-02 3:49 ` David Miller
2011-04-02 3:52 ` David Miller
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