Re: [RFC] Use RCU for tcp_ehash lookup
From: Andi Kleen <hidden>
Date: 2004-09-02 21:28:42
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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.
quoted
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