From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46970) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1Ec4-00018J-QQ for qemu-devel@nongnu.org; Tue, 24 Nov 2015 09:30:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a1Ec0-0004ww-RU for qemu-devel@nongnu.org; Tue, 24 Nov 2015 09:30:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41957) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1Ec0-0004wZ-NN for qemu-devel@nongnu.org; Tue, 24 Nov 2015 09:30:28 -0500 References: <1447694618-17177-3-git-send-email-marcandre.lureau@redhat.com> <1447837378-25222-1-git-send-email-marcandre.lureau@redhat.com> <20151118224821-mutt-send-email-mst@redhat.com> <56534FAA.4090101@redhat.com> <20151123181008.GU18085@redhat.com> <20151124160921-mutt-send-email-mst@redhat.com> <20151124141936.GJ9981@redhat.com> <20151124162004-mutt-send-email-mst@redhat.com> From: Paolo Bonzini Message-ID: <5654747F.9050004@redhat.com> Date: Tue, 24 Nov 2015 15:30:23 +0100 MIME-Version: 1.0 In-Reply-To: <20151124162004-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] exec: silence hugetlbfs warning under qtest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , "Daniel P. Berrange" Cc: Amit Shah , Peter Maydell , =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= , QEMU On 24/11/2015 15:25, Michael S. Tsirkin wrote: > I'm worried that things go slow and people don't have a way to find out > why, and documentation isn't the first place people look for when facing > a performance issue. > > At the moment we call MADV_HUGEPAGE unconditionally and unfortunately > there's no way to report it's not having the intended effect. > > Maybe we want a "don't enable hugepages" flag. > That could also have the effect of suppressing the warnings. THP is anyway slower than hugetlbfs. If people really want performance, they need to use hugetlbfs. For everything else I'd be surprised if they even notice. Paolo