Date: Thu, 18 Sep 2008 11:58:27 -0700 From: "Kevin Oberman" <oberman@es.net> To: "Jian Qiu" <swordqiu@gmail.com> Cc: freebsd-net@freebsd.org Subject: Re: What's the status of parallel netisr? Message-ID: <20080918185827.E05DA45047@ptavv.es.net> In-Reply-To: Your message of "Thu, 18 Sep 2008 22:50:10 %2B0800." <e8520310809180750h41ddd3e9tb83f20953f1c8095@mail.gmail.com>
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--==_Exmh_1221764307_89905P Content-Type: text/plain; charset=us-ascii Content-Disposition: inline > Date: Thu, 18 Sep 2008 22:50:10 +0800 > From: "Jian Qiu" <swordqiu@gmail.com> > Sender: owner-freebsd-net@freebsd.org > > Thanks again for the info. > > As you suggested, I did test on the most recent 7.0-stable-200807 kernel. > > The SMP throughout on the new kernel was improved to around 90MB/s. > > However, SMP kernel still had no advantage over UP, at least for this > kind of single threaded applications. > > I further did the same test on Linux with both SMP and UP. > > I did observe the same trend. > > The throughput on UP (~210MB/ecs) was also much better than SMP (~170MB/sec). > > However, I was surprised again that the local UDP throughput on Linux > was more than double of FreeBSD. > > Since all these tests were performed on the same machine, it must be > because of the kernel that made such big differences. > > I'm curious what is the major performance bottleneck in FreeBSD network stack?? > > Is there any plan in community to address these issues? Did you try locking down the CPUs used with cpuset (FreeBSD) or taskset (Linux)? This can make a very substantial difference. Something like a UDP canon will run far more efficiently if locked to a single CPU and will run best if that CPU is not processing the interrupts. -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751 --==_Exmh_1221764307_89905P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) Comment: Exmh version 2.5 06/03/2002 iD8DBQFI0qTTkn3rs5h7N1ERArElAJ9F9CZG9WHGTQv1+fFkcF8pSLkHGwCguAb0 +qXkgaxoKYLKHCL4r3WxsB8= =6VIt -----END PGP SIGNATURE----- --==_Exmh_1221764307_89905P--
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