From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51389) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1avFZf-00033g-8D for qemu-devel@nongnu.org; Tue, 26 Apr 2016 22:51:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1avFZa-00069s-8a for qemu-devel@nongnu.org; Tue, 26 Apr 2016 22:51:35 -0400 Received: from [59.151.112.132] (port=55094 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1avFZZ-00069G-Lq for qemu-devel@nongnu.org; Tue, 26 Apr 2016 22:51:30 -0400 References: <1461722868-11624-1-git-send-email-zhoujie2011@cn.fujitsu.com> <57202190.9070106@cn.fujitsu.com> <20160427024626.GB17756@octofox.metropolis> From: Zhou Jie Message-ID: <57202929.4060903@cn.fujitsu.com> Date: Wed, 27 Apr 2016 10:51:21 +0800 MIME-Version: 1.0 In-Reply-To: <20160427024626.GB17756@octofox.metropolis> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] hw/net/opencores_eth: Allocating Large sized arrays to heap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Filippov Cc: qemu-devel@nongnu.org On 2016/4/27 10:46, Max Filippov wrote: > Hi Zhou, > > On Wed, Apr 27, 2016 at 10:18:56AM +0800, Zhou Jie wrote: >> When I committed another patch which named as >> "hw/net/virtio-net: Allocating Large sized arrays to heap" . >> >> Christian Borntraeger said that 16k is usually perfectly fine >> for a userspace stack and doing allocations in a hot path >> might actually hurt performance. >> >> Although the size is 65536 bytes here, >> I think open_eth_start_xmit is in a hot path. >> So, it is OK, if you think that this patch should not be applied. > > With Linux as guest OS we shouldn't see any allocations > as it doesn't send huge packets, so I think this patch is fine. > I can take it through the xtensa tree if you don't have other > plan. > OK, Thanks Sincerely, Zhou Jie