netdev - Re: [PATCH] tun: do not put self in waitq if doing a nonblock read

lists.openwall.net		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 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Thu, 09 Jun 2011 00:27:21 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	akong@...hat.com
Cc:	netdev@...r.kernel.org, jasowang@...hat.com, kvm@...r.kernel.org,
	mst@...hat.com
Subject: Re: [PATCH] tun: do not put self in waitq if doing a nonblock read

From: Amos Kong <akong@...hat.com>
Date: Thu, 09 Jun 2011 07:46:06 +0800

> Perf shows a relatively high rate (about 8%) race in
> spin_lock_irqsave() when doing netperf between external host and
> guest. It's mainly becuase the lock contention between the
> tun_do_read() and tun_xmit_skb(), so this patch do not put self into
> waitqueue to reduce this kind of race. After this patch, it drops to
> 4%.
> 
> Signed-off-by: Jason Wang <jasowang@...hat.com>
> Signed-off-by: Amos Kong <akong@...hat.com>

Applied, thanks.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html