From: Ben Greear <greearb@candelatech.com>
To: Eric Dumazet <eric.dumazet@gmail.com>, Thomas Graf <tgraf@suug.ch>
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: Re: [PATCH net-next] pktgen: Add NOINIT option to leave packet data uninitialized
Date: Fri, 16 May 2014 06:28:38 -0700 [thread overview]
Message-ID: <53761286.2040505@candelatech.com> (raw)
In-Reply-To: <1400246202.7973.163.camel@edumazet-glaptop2.roam.corp.google.com>
On 05/16/2014 06:16 AM, Eric Dumazet wrote:
> On Fri, 2014-05-16 at 12:34 +0200, Thomas Graf wrote:
>> The memset() on the packet data is expensive and severely limiting
>> the pps throughput for large frame sizes.
>>
>> Considering that pktgen requires root privileges to run it is safe
>> to introduce an option to optionally avoid the memset() and leave
>> the packet data uninitialized.
>>
>> VM test results, 2 VCPU, 2 threads, pkt_size=9K:
>>
>> 12.44% -11.15% [kernel.kallsyms] [k] memset
>> 4.84% +1.58% [kernel.kallsyms] [k] get_page_from_freelist
>>
>> Signed-off-by: Thomas Graf <tgraf@suug.ch>
>> ---
>> Documentation/networking/pktgen.txt | 3 +++
>> net/core/pktgen.c | 16 ++++++++++++++--
>> 2 files changed, 17 insertions(+), 2 deletions(-)
>
> We do not want to leak content of memory, even if 'root' is willing to.
>
> Sorry, you need to do something else if you really care.
Is there currently no other way for root to grab memory contents and
send them over the network?
I mean, it could load it's own module and do bad things if nothing else?
Thanks,
Ben
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
next prev parent reply other threads:[~2014-05-16 13:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-16 10:34 [PATCH net-next] pktgen: Add NOINIT option to leave packet data uninitialized Thomas Graf
2014-05-16 13:16 ` Eric Dumazet
2014-05-16 13:28 ` Ben Greear [this message]
2014-05-16 14:23 ` Eric Dumazet
2014-05-16 14:50 ` Thomas Graf
2014-05-16 15:08 ` Eric Dumazet
2014-05-16 15:20 ` Thomas Graf
2014-05-16 15:26 ` Eric Dumazet
2014-05-16 15:39 ` Thomas Graf
2014-05-16 16:15 ` Eric Dumazet
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=53761286.2040505@candelatech.com \
--to=greearb@candelatech.com \
--cc=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=tgraf@suug.ch \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.