From: Gross, M. <mar...@in...> - 2003-09-30 18:31:50
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I will only be introducing some of the work I'm doing. The following is a short blurb I'll be speaking too tomorrow. I plan to briefly talk about some of the specifics for the topics listed below. I am working on the general area of root causing, and perhaps fixing, why applications ported to Linux tend to fall on their faces as the system is placed under stress of some kind. This work is being done under the Carrier Grade Linux umbrella and is motivated by input from repeated Telco ISV and system integrator feed back on there attempts to port to Linux from Solaris. The typical applications are soft real time, and they work when ported from Solaris to Linux. Until, the point the workload on the Linux platform starts to get "large". The only thing we know about the metric "large" is that similar loads on Solaris do not cause a problem, where under Linux the performance degrades non-linearly. Unfortunately, the ISV and system integrator folks making these accusations are working with internal and closely guarded software or, otherwise difficult to reproduce, systems. This makes application specific detailed study difficult. The following is a partial list of things I'm working on, and I welcome any input or involvement on these or related topics. 1) Latency degradation of simple real time POSIX API test cases as a system work loads scale. 2) Considering the development of tools to help locate kernel bottlenecks. 3) I/O throughput --mgross > -----Original Message----- > From: Hanna Linder [mailto:ha...@us...]=20 > Sent: Monday, September 29, 2003 2:26 PM > To: lin...@vg...; lin...@vg...;=20 > lse...@li... > Cc: syl...@bu...; Sim...@bu...; Gross, Mark > Subject: 10/1 LSE call topics: Cpusets and real-time app needs. >=20 >=20 >=20 > LSE Con Call Agenda for Wednesday Oct 1, 2003 >=20 > Typically the presenter gives a brief overview of their topic > then the rest of the time is left open for questions. >=20 > I. Sylvain Jeaugey and Simon Derr: CPUSETS, Controlling CPU placement. >=20 http://marc.theaimsgroup.com/?l=3Dlse-tech&m=3D106441942222186&w=3D2 II. Mark Gross: Real-Time applications needs when system is stressed.=20 III. Anything else if time permits. USA Toll Free: 1-800-967-7148 International Toll: +1-719-457-2710 Passcode: 298900 10:00am PDT (1700 GMT) |
From: Andi K. <ak...@su...> - 2003-09-30 18:59:43
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> > The following is a partial list of things I'm working on, and I welcome > any input or involvement on these or related topics. > > 1) Latency degradation of simple real time POSIX API test cases as > a system work loads scale. If you release the simple test cases and post pointers to them to linux-kernel you could actually get help in fixing them. I suspect the work to do that would quickly pay off ;-) > 2) Considering the development of tools to help locate kernel > bottlenecks. There are plenty of tools around for various purposes. Lots of profilers like oprofile. IIRC the reiserfs people have an sleep-o-meter patch that may be useful to find problems that are caused by ineffective sleeping. -Andi |