From: Michael Tokarev <mjt@tls.msk.ru>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Avi Kivity <avi@redhat.com>,
ben@iagu.net, KVM list <kvm@vger.kernel.org>
Subject: Re: KVM lock contention on 48 core AMD machine
Date: Mon, 21 Mar 2011 21:48:19 +0300 [thread overview]
Message-ID: <4D879D73.2090608@msgid.tls.msk.ru> (raw)
In-Reply-To: <1300727545.2884.513.camel@edumazet-laptop>
21.03.2011 20:12, Eric Dumazet wrote:
> Le lundi 21 mars 2011 à 19:02 +0200, Avi Kivity a écrit :
>
>> Any ideas on how to fix it? We could pre-allocate IDs and batch them in
>> per-cpu caches, but it seems like a lot of work.
>>
>
> Hmm, I dont know what syscalls kvm do, but even a timer_gettime() has to
> lock this idr_lock.
I wonder why my testcase - 160 kvm guests on a 2-core AMD AthlonII CPU -
shows no contention of that sort, not at all... Yes sure, all these
(linux) guests are idling at login: prompt, but I'd expect at least
some gettimeofday() and some load average, -- everything stays close
to zero.
/mjt
next prev parent reply other threads:[~2011-03-21 18:48 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-18 12:02 KVM lock contention on 48 core AMD machine Ben Nagy
2011-03-18 12:30 ` Joerg Roedel
2011-03-19 4:45 ` Ben Nagy
2011-03-21 9:50 ` Avi Kivity
2011-03-21 11:43 ` Ben Nagy
2011-03-21 13:41 ` Ben Nagy
2011-03-21 13:53 ` Avi Kivity
[not found] ` <AANLkTikWQS281kTtJ32-qo5U+w_BAak7qUwVhUQgOxxv@mail.gmail.com>
2011-03-21 15:50 ` Avi Kivity
2011-03-21 16:16 ` Ben Nagy
2011-03-21 16:33 ` Avi Kivity
2011-03-21 16:54 ` Eric Dumazet
2011-03-21 17:02 ` Avi Kivity
2011-03-21 17:12 ` Eric Dumazet
2011-03-21 18:12 ` Ben Nagy
2011-03-21 22:27 ` [RFC] posix-timers: RCU conversion Eric Dumazet
2011-03-22 7:09 ` [PATCH] " Eric Dumazet
2011-03-22 8:59 ` Ben Nagy
2011-03-22 10:35 ` Avi Kivity
2011-03-22 10:35 ` Avi Kivity
2011-04-04 3:30 ` Ben Nagy
2011-04-04 7:18 ` Avi Kivity
2011-04-04 7:18 ` Avi Kivity
2011-04-05 7:49 ` Peter Zijlstra
2011-04-05 8:16 ` Avi Kivity
2011-04-05 8:16 ` Avi Kivity
2011-04-05 8:48 ` Peter Zijlstra
2011-04-05 8:56 ` Avi Kivity
2011-04-05 8:56 ` Avi Kivity
2011-04-05 9:03 ` Peter Zijlstra
2011-04-05 9:08 ` Avi Kivity
2011-04-05 9:08 ` Avi Kivity
2011-04-05 9:50 ` Ben Nagy
2011-04-05 8:56 ` Mike Galbraith
2011-04-03 16:54 ` Eric Dumazet
2011-04-04 18:08 ` john stultz
2011-04-04 19:47 ` Eric Dumazet
2011-04-05 14:48 ` Oleg Nesterov
2011-04-05 15:18 ` [PATCH v2] " Eric Dumazet
2011-04-05 15:43 ` Oleg Nesterov
2011-05-16 15:10 ` Avi Kivity
2011-05-16 15:30 ` Eric Dumazet
2011-04-08 18:28 ` [PATCH] " Paul E. McKenney
2011-03-21 18:14 ` KVM lock contention on 48 core AMD machine Avi Kivity
2011-03-21 18:48 ` Michael Tokarev [this message]
2011-03-21 18:53 ` Avi Kivity
2011-03-18 12:44 ` Stefan Hajnoczi
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