From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Kenneth W" Date: Thu, 03 Nov 2005 19:59:00 +0000 Subject: RE: [RFC] 4-level page table directories. Message-Id: <200511031959.jA3Jx0g29354@unix-os.sc.intel.com> List-Id: References: <20051027041709.GA13193@attica.americas.sgi.com> In-Reply-To: <20051027041709.GA13193@attica.americas.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Robin Holt wrote on Thursday, November 03, 2005 8:37 AM > On Wed, Nov 02, 2005 at 05:53:10PM -0800, Chen, Kenneth W wrote: > > I just did a quick measurement with I/O submission path. get_user_pages > > is my biggest concern that extra level means more code and cache foot > > print for each I/O submission. It cost about 1.5% more in I/O path > > length on a micro-benchmark (from block layer and Up). This could be > > all buried as noise in a larger scheme for industry database benchmark. > > Can you point me at the benchmark? Here, kernel null blk driver: http://marc.theaimsgroup.com/?l=linux-kernel&m1033439400836&w=2 And here: user space micro-benchmark: http://marc.theaimsgroup.com/?l=linux-kernel&m1033404219628&w=2 - Ken