From: Andi Kleen <ak@suse.de>
To: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>,
davem@redhat.com, netdev@oss.sgi.com,
linux-kernel@vger.kernel.org, Dipankar <dipankar@in.ibm.com>,
paulmck@us.ibm.com
Subject: Re: [RFC] Use RCU for tcp_ehash lookup
Date: Thu, 2 Sep 2004 23:19:50 +0200 [thread overview]
Message-ID: <20040902211950.GH16175@wotan.suse.de> (raw)
In-Reply-To: <20040901113641.GA3918@in.ibm.com>
On Wed, Sep 01, 2004 at 05:06:41PM +0530, Srivatsa Vaddagiri wrote:
> | 2.6.8.1 | 2.6.8.1 + my patch
> -------------------------------------------------------------------------------
> Average cycles | |
> spent in | |
> __tcp_v4_lookup_established | 2970.65 | 668.227
> | (~3.3 micro-seconds) | (~0.74 microseconds)
> -------------------------------------------------------------------------------
>
> This repesents improvement by a factor of 77.5%!
Nice.
>
>
> >
> > And it should also fix the performance problems with
> > cat /proc/net/tcp on ppc64/ia64 for large hash tables because the rw locks
> > are gone.
>
> But spinlocks are in! Would that still improve the performance compared to rw
> locks? (See me earlier note where I have explained that lookup done for
> /proc/net/tcp is _not_ lock-free yet).
Yes, spinlocks are much faster than rwlocks.
-Andi
next prev parent reply other threads:[~2004-09-02 21:19 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-31 12:59 [RFC] Use RCU for tcp_ehash lookup Srivatsa Vaddagiri
2004-08-31 13:04 ` Srivatsa Vaddagiri
2004-08-31 13:12 ` Srivatsa Vaddagiri
2004-08-31 13:54 ` Andi Kleen
2004-09-01 11:36 ` Srivatsa Vaddagiri
2004-09-02 5:45 ` David S. Miller
2004-09-02 21:19 ` Andi Kleen [this message]
2004-09-02 5:43 ` David S. Miller
2004-09-02 5:41 ` David S. Miller
2004-09-02 14:04 ` Srivatsa Vaddagiri
2004-09-02 16:31 ` Paul E. McKenney
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