From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx107.postini.com [74.125.245.107]) by kanga.kvack.org (Postfix) with SMTP id 35EEA6B004D for ; Fri, 20 Apr 2012 21:56:22 -0400 (EDT) Received: by pbcup15 with SMTP id up15so2072832pbc.14 for ; Fri, 20 Apr 2012 18:56:21 -0700 (PDT) Date: Sat, 21 Apr 2012 10:56:15 +0900 From: Takuya Yoshikawa Subject: Re: [PATCH] kvm: don't call mmu_shrinker w/o used_mmu_pages Message-Id: <20120421105615.6b0b03640f7553060628d840@gmail.com> In-Reply-To: References: <1334356721-9009-1-git-send-email-yinghan@google.com> <20120420151143.433c514e.akpm@linux-foundation.org> <4F91E8CC.5080409@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Ying Han Cc: Rik van Riel , Andrew Morton , Michal Hocko , Johannes Weiner , Mel Gorman , KAMEZAWA Hiroyuki , Hillf Danton , Hugh Dickins , Dan Magenheimer , linux-mm@kvack.org, kvm@vger.kernel.org, Avi Kivity , Marcelo Tosatti , Mike Waychison On Fri, 20 Apr 2012 16:07:41 -0700 Ying Han wrote: > My understanding of the real pain is the poor implementation of the > mmu_shrinker. It iterates all the registered mmu_shrink callbacks for > each kvm and only does little work at a time while holding two big > locks. I learned from mikew@ (also ++cc-ed) that is causing latency > spikes and unfairness among kvm instance in some of the experiment > we've seen. Last year, I discussed the mmu_shrink issues on kvm ML: [PATCH 0/4] KVM: Make mmu_shrink() scan nr_to_scan shadow pages http://www.spinics.net/lists/kvm/msg65231.html Sadly, we could not find any good way at that time. Thanks, Takuya -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org