From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Kenneth W" Date: Tue, 25 Jan 2005 19:57:53 +0000 Subject: RE: optimize __gp location Message-Id: <200501251957.j0PJvsg17422@unix-os.sc.intel.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On Tue, 25 Jan 2005 11:44:34 -0800, "Chen, Kenneth W" said: Ken> I don't have any benchmark result off hand. But digging through recent Ken> data, for a well known db benchmark, GOT table access account to about Ken> 4% of total memory latency in the kernel. David Mosberger wrote on Tuesday, January 25, 2005 11:52 AM > > 4% actual CPU stalls or 4% of potentially overlapped stalls? > 4% of total cpu stall cycles. 6% of all memory references (in kernel space). Though they are very concentrated to a few cache lines. > I'm not trying to be difficult. It's just that GOT optimizations so > far haven't really paid off in any significant way in the benchmarks I > tried. You'd think for some benchmarks it does make a significant > difference (even just based on a cache-pollution argument), I just > haven't seen it yet... No biggy, I want to find out myself too whether this has any real impact or not :-) - Ken