From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v1] vhost: avoid large order allocations Date: Tue, 13 May 2014 18:15:27 +0300 Message-ID: <20140513151527.GA28517@redhat.com> References: <1399970133-46783-1-git-send-email-mimu@linux.vnet.ibm.com> <1399970133-46783-2-git-send-email-mimu@linux.vnet.ibm.com> <20140513084049.GE29442@redhat.com> <87tx8tg3a1.fsf@kima.orebokech.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: ddongch@cn.ibm.com, Michael Mueller , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, borntraeger@de.ibm.com To: Romain Francoise Return-path: Content-Disposition: inline In-Reply-To: <87tx8tg3a1.fsf@kima.orebokech.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org On Tue, May 13, 2014 at 04:29:58PM +0200, Romain Francoise wrote: > "Michael S. Tsirkin" writes: > > > Please dont' do this, extra indirection hurts performance. > > Instead, please change vhost_net_open and scsi to allocate the whole > > structure with vmalloc if kmalloc fails, along the lines of > > 74d332c13b2148ae934ea94dac1745ae92efe8e5 > > Back in January 2013, you didn't seem to think it was a good idea: > > https://lkml.org/lkml/2013/1/23/492 Hmm true, and Dave thought the structure's too large. I'll have to do some benchmarks to see what the effect of Michael's patch is, performance-wise. If it's too expensive I can pick up your patch, no need to repost. -- MST