From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39572) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bG65W-0007ej-1Q for qemu-devel@nongnu.org; Thu, 23 Jun 2016 10:58:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bG65P-00082f-V9 for qemu-devel@nongnu.org; Thu, 23 Jun 2016 10:58:36 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:35558 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bG65P-000829-OG for qemu-devel@nongnu.org; Thu, 23 Jun 2016 10:58:31 -0400 References: <5768F923.7040502@kamp.de> <20160621131815.GB2264@work-vm> From: Peter Lieven Message-ID: <576BF910.70304@kamp.de> Date: Thu, 23 Jun 2016 16:58:24 +0200 MIME-Version: 1.0 In-Reply-To: <20160621131815.GB2264@work-vm> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Qemu and heavily increased RSS usage List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: "qemu-devel@nongnu.org" , Paolo Bonzini , Fam Zheng , Peter Maydell Am 21.06.2016 um 15:18 schrieb Dr. David Alan Gilbert: > * Peter Lieven (pl@kamp.de) wrote: >> Hi, >> >> while upgrading from Qemu 2.2.0 to Qemu 2.5.1.1 I noticed that the RSS memory usage has heavily increased. >> We use hugepages so the RSS memory does not include VM memory. In Qemu 2.2.0 it used to be ~30MB per vServer >> and increased to up to 300 - 400MB for Qemu 2.5.1.1 (same with master). The memory increases over time, but seems >> not to grow indefinetly. I tried to bisect, but had no result so far that made sense. I also tried valgrind / massif, but >> valgrind does not see the allocation (at least at exit) and massif fails to rund due to - so it pretends - heap corruption. >> >> Any help or ideas how to debug further would be appreciated. > I think I'd try stripping devices off; can you get a similar difference > to happen with a guest with no USB, no hugepages, no VGA and a simple > locally stored IDE disk? > > If you're having trouble bisecting is it possible it's a change > in one of the libraries it's linked against? > > There was someone asking the other day on #qemu who had a setup that > was apparently using much more RAM than expected and we didn't > manage to track it down but I can't remember the version being used. I currently trying to track the increased usage from release to release. The first increase of RSS usage from ~25MB to ~35MB directly after machine setup is introduced by this patch: commit ba3f4f64b0e941b9e03568b826746941bef071f9 Author: Paolo Bonzini Date: Wed Jan 21 12:09:14 2015 +0100 exec: RCUify AddressSpaceDispatch Note that even after this patch, most callers of address_space_* functions must still be under the big QEMU lock, otherwise the memory region returned by address_space_translate can disappear as soon as address_space_translate returns. This will be fixed in the next part of this series. Reviewed-by: Fam Zheng Signed-off-by: Paolo Bonzini @Paolo, @Fam, any idea? Thanks, Peter