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diff --git a/share/doc/papers/kerntune/4.t b/share/doc/papers/kerntune/4.t new file mode 100644 index 0000000..fcd0ad0 --- /dev/null +++ b/share/doc/papers/kerntune/4.t @@ -0,0 +1,99 @@ +.\" Copyright (c) 1984 M. K. McKusick +.\" Copyright (c) 1984 The Regents of the University of California. +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)4.t 1.2 (Berkeley) 11/8/90 +.\" +.ds RH Conclusions +.NH 1 +Conclusions +.PP +We have created a profiler that aids in the evaluation +of the kernel. +For each routine in the kernel, +the profile shows the extent to which that routine +helps support various abstractions, +and how that routine uses other abstractions. +The profile assesses the cost of routines +at all levels of the kernel decomposition. +The profiler is easily used, +and can be compiled into the kernel. +It adds only five to thirty percent execution overhead to the kernel +being profiled, +produces no additional output while the kernel is running +and allows the kernel to be measured in its real environment. +Kernel profiles can be used to identify bottlenecks in performance. +We have shown how to improve performance +by caching recently calculated name translations. +The combined caches added to the name translation process +reduce the average cost of translating a pathname to an inode by 35%. +These changes reduce the percentage of time spent running +in the system by nearly 9%. +.nr H2 1 +.ds RH Acknowledgements +.SH +\s+2Acknowledgements\s0 +.PP +I would like to thank Robert Elz for sharing his ideas and +his code for cacheing system wide names. +Thanks also to all the users at Berkeley who provided all the +input to generate the kernel profiles. +This work was supported by +the Defense Advance Research Projects Agency (DoD) under +Arpa Order No. 4031 monitored by Naval Electronic System Command under +Contract No. N00039-82-C-0235. +.ds RH References +.nr H2 1 +.sp 2 +.SH +\s+2References\s-2 +.LP +.IP [Bentley81] 20 +Bentley, J. L., +``Writing Efficient Code'', +Department of Computer Science, +Carnegie-Mellon University, +Pittsburgh, Pennsylvania, +CMU-CS-81-116, 1981. +.IP [Graham82] 20 +Graham, S., Kessler, P., McKusick, M., +``gprof: A Call Graph Execution Profiler'', +Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, +Volume 17, Number 6, June 1982. pp 120-126 +.IP [Graham83] 20 +Graham, S., Kessler, P., McKusick, M., +``An Execution Profiler for Modular Programs'' +Software - Practice and Experience, +Volume 13, 1983. pp 671-685 +.IP [Ritchie74] 20 +Ritchie, D. M. and Thompson, K., +``The UNIX Time-Sharing System'', +CACM 17, 7. July 1974. pp 365-375 |
