lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Wed, 29 Nov 2006 18:19:50 -0800 (PST)
From:	David Miller <>
Subject: Re: [patch 1/4] - Potential performance bottleneck for Linxu TCP

From: Wenji Wu <>
Date: Wed, 29 Nov 2006 19:56:58 -0600

> >We could also pepper tcp_recvmsg() with some very carefully placed
> >preemption disable/enable calls to deal with this even with
> >CONFIG_PREEMPT enabled.
> I also think about this approach. But since the "problem" happens in
> the 2.6 Desktop and Low-latency Desktop (not server), system
> responsiveness is a key feature, simply placing preemption
> disabled/enable call might not work.  If you want to place
> preemption disable/enable calls within tcp_recvmsg, you have to put
> them in the very beginning and end of the call. Disabling preemption
> would degrade system responsiveness.

We can make explicitl preemption checks in the main loop of
tcp_recvmsg(), and release the socket and run the backlog if
need_resched() is TRUE.

This is the simplest and most elegant solution to this problem.

The one suggested in your patch and paper are way overkill, there is
no reason to solve a TCP specific problem inside of the generic
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists