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diff --git a/share/doc/papers/diskperf/results.ms b/share/doc/papers/diskperf/results.ms new file mode 100644 index 000000000000..09f61a81824f --- /dev/null +++ b/share/doc/papers/diskperf/results.ms @@ -0,0 +1,337 @@ +.\" Copyright (c) 1983 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. +.\" +.\" @(#)results.ms 6.2 (Berkeley) 4/16/91 +.\" +.ds RH Results +.NH +Results +.PP +The following tables indicate the results of our +test runs. +Note that each table contains results for tests run +on two varieties of 4.2BSD file systems. +The first set of results is always for a file system +with a basic blocking factor of eight Kilobytes and a +fragment size of 1 Kilobyte. The second sets of measurements +are for file systems with a four Kilobyte block size and a +one Kilobyte fragment size. +The values in parenthesis indicate the percentage of CPU +time used by the test program. +In the case of the two disk arm tests, +the value in parenthesis indicates the sum of the percentage +of the test programs that were run. +Entries of ``n. m.'' indicate this value was not measured. +.DS +.TS +box,center; +c s s s s +c s s s s +c s s s s +l | l s | l s +l | l s | l s +l | l l | l l +l | c c | c c. +4.2BSD File Systems Tests - \fBVAX 11/750\fR += +Logically Sequential Transfers +from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test Emulex SC750/Eagle UDA50/RA81 + + 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 490 (69%) 620 (96%) 310 (44%) 520 (65%) +write_4096 380 (99%) 370 (99%) 370 (97%) 360 (98%) +write_8192 470 (99%) 470 (99%) 320 (71%) 410 (83%) +rewrite_8192 650 (99%) 620 (99%) 310 (50%) 450 (70%) += +.T& +c s s s s +c s s s s +l | l s | l s +l | l s | l s +l | l l | l l +l | c c | c c. +Logically Sequential Transfers +from \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test Emulex SC750/Eagle UDA50/RA81 + + 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 300 (60%) 400 (84%) 210 (42%) 340 (77%) +write_4096 320 (98%) 320 (98%) 220 (67%) 290 (99%) +write_8192 340 (98%) 340 (99%) 220 (65%) 310 (98%) +rewrite_8192 450 (99%) 450 (98%) 230 (47%) 340 (78%) +.TE +.DE +.PP +Note that the rate of write operations on the VAX 11/750 are ultimately +CPU limited in some cases. +The write rates saturate the CPU at a lower bandwidth than the reads +because they must do disk allocation in addition to moving the data +from the user program to the disk. +The UDA50/RA81 saturates the CPU at a lower transfer rate for a given +operation than the SC750/Eagle because +it causes more memory contention with the CPU. +We do not know if this contention is caused by +the UNIBUS controller or the UDA50. +.PP +The following table reports the results of test runs on a VAX 11/780 +with 4 Megabytes of main memory. +.DS +.TS +box,center; +c s s s s s s +c s s s s s s +c s s s s s s +l | l s | l s | l s +l | l s | l s | l s +l | l l | l l | l l +l | c c | c c | c c. +4.2BSD File Systems Tests - \fBVAX 11/780\fR += +Logically Sequential Transfers +from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test Emulex SC780/Eagle UDA50/RA81 Sys. Ind. 9900/Eagle + + 1 Drive 2 Drives 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 560 (70%) 480 (58%) 360 (45%) 540 (72%) 340 (41%) 520 (66%) +write_4096 440 (98%) 440 (98%) 380 (99%) 480 (96%) 490 (96%) 440 (84%) +write_8192 490 (98%) 490 (98%) 220 (58%)* 480 (92%) 490 (80%) 430 (72%) +rewrite_8192 760 (100%) 560 (72%) 220 (50%)* 180 (52%)* 490 (60%) 520 (62%) += +.T& +c s s s s s s +c s s s s s s +l | l s | l s | l s +l | l s | l s | l s +l | l l | l l | l l +l | c c | c c | c c. +Logically Sequential Transfers +from an \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test Emulex SC780/Eagle UDA50/RA81 Sys. Ind. 9900/Eagle + + 1 Drive 2 Drives 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 490 (77%) 370 (66%) n.m. n.m. 200 (31%) 370 (56%) +write_4096 380 (98%) 370 (98%) n.m. n.m. 200 (46%) 370 (88%) +write_8192 380 (99%) 370 (97%) n.m. n.m. 200 (45%) 320 (76%) +rewrite_8192 490 (87%) 350 (66%) n.m. n.m. 200 (31%) 300 (46%) +.TE +* the operation of the hardware was suspect during these tests. +.DE +.PP +The dropoff in reading and writing rates for the two drive SC780/Eagle +tests are probably due to the file system using insufficient +rotational delay for these tests. +We have not fully investigated these times. +.PP +The following table compares data rates on VAX 11/750s directly +with those of VAX 11/780s using the UDA50/RA81 storage system. +.DS +.TS +box,center; +c s s s s +c s s s s +c s s s s +l | l s | l s +l | l s | l s +l | l l | l l +l | c c | c c. +4.2BSD File Systems Tests - \fBDEC UDA50 - 750 vs. 780\fR += +Logically Sequential Transfers +from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test VAX 11/750 UNIBUS VAX 11/780 UNIBUS + + 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 310 (44%) 520 (84%) 360 (45%) 540 (72%) +write_4096 370 (97%) 360 (100%) 380 (99%) 480 (96%) +write_8192 320 (71%) 410 (96%) 220 (58%)* 480 (92%) +rewrite_8192 310 (50%) 450 (80%) 220 (50%)* 180 (52%)* += +.T& +c s s s s +c s s s s +l | l s | l s +l | l s | l s +l | l l | l l +l | c c | c c. +Logically Sequential Transfers +from an \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test VAX 11/750 UNIBUS VAX 11/780 UNIBUS + + 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 210 (42%) 342 (77%) n.m. n.m. +write_4096 215 (67%) 294 (99%) n.m. n.m. +write_8192 215 (65%) 305 (98%) n.m. n.m. +rewrite_8192 227 (47%) 336 (78%) n.m. n.m. +.TE +* the operation of the hardware was suspect during these tests. +.DE +.PP +The higher throughput available on VAX 11/780s is due to a number +of factors. +The larger main memory size allows a larger file system cache. +The block allocation routines run faster, raising the upper limit +on the data rates in writing new files. +.PP +The next table makes the same comparison using an Emulex controller +on both systems. +.DS +.TS +box, center; +c s s s s +c s s s s +c s s s s +l | l s | l s +l | l s | l s +l | l l | l l +l | c c | c c. +4.2BSD File Systems Tests - \fBEmulex - 750 vs. 780\fR += +Logically Sequential Transfers +from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test VAX 11/750 CMI Bus VAX 11/780 SBI Bus + + 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 490 (69%) 620 (96%) 560 (70%) 480 (58%) +write_4096 380 (99%) 370 (99%) 440 (98%) 440 (98%) +write_8192 470 (99%) 470 (99%) 490 (98%) 490 (98%) +rewrite_8192 650 (99%) 620 (99%) 760 (100%) 560 (72%) += +.T& +c s s s s +c s s s s +l | l s | l s +l | l s | l s +l | l l | l l +l | c c | c c. +Logically Sequential Transfers +from an \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test VAX 11/750 CMI Bus VAX 11/780 SBI Bus + + 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 300 (60%) 400 (84%) 490 (77%) 370 (66%) +write_4096 320 (98%) 320 (98%) 380 (98%) 370 (98%) +write_8192 340 (98%) 340 (99%) 380 (99%) 370 (97%) +rewrite_8192 450 (99%) 450 (98%) 490 (87%) 350 (66%) +.TE +.DE +.PP +The following table illustrates the evolution of our testing +process as both hardware and software problems effecting +the performance of the Emulex SC780 were corrected. +The software change was suggested to us by George Goble +of Purdue University. +.PP +The 4.2BSD handler for RH750/RH780 interfaced disk drives +contains several constants which to determine how +much time is provided between an interrupt signaling the completion +of a positioning command and the subsequent start of a data transfer +operation. These lead times are expressed as sectors of rotational delay. +If they are too small, an extra complete rotation will often be required +between a seek and subsequent read or write operation. +The higher bit rate and rotational speed of the 2351A Fujitsu +disk drives required +increasing these constants. +.PP +The hardware change involved allowing for slightly longer +delays in arbitrating for cycles on the SBI bus by +starting the bus arbitration cycle a little further ahead of +when the data was ready for transfer. +Finally we had to increase the rotational delay between consecutive +blocks in the file because +the higher bandwidth from the disk generated more memory contention, +which slowed down the processor. +.DS +.TS +box,center,expand; +c s s s s s s +c s s s s s s +c s s s s s s +l | l s | l s | l s +l | l s | l s | l s +l | l s | l s | l s +l | c c | c c | c c +l | c c | c c | c c. +4.2BSD File Systems Tests - \fBEmulex SC780 Disk Controller Evolution\fR += +Logically Sequential Transfers +from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test Inadequate Search Lead OK Search Lead OK Search Lead + Initial SBI Arbitration Init SBI Arb. Improved SBI Arb. + + 1 Drive 2 Drives 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 320 370 440 (60%) n.m. 560 (70%) 480 (58%) +write_4096 250 270 300 (63%) n.m. 440 (98%) 440 (98%) +write_8192 250 280 340 (60%) n.m. 490 (98%) 490 (98%) +rewrite_8192 250 290 380 (48%) n.m. 760 (100%) 560 (72%) += +.T& +c s s s s s s +c s s s s s s +l | l s | l s | l s +l | l s | l s | l s +l | l s | l s | l s +l | c c | c c | c c +l | c c | c c | c c. +Logically Sequential Transfers +from an \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.) +_ +Test Inadequate Search Lead OK Search Lead OK Search Lead + Initial SBI Arbitration Init SBI Arb. Improved SBI Arb. + + 1 Drive 2 Drives 1 Drive 2 Drives 1 Drive 2 Drives +_ +read_8192 200 220 280 n.m. 490 (77%) 370 (66%) +write_4096 180 190 300 n.m. 380 (98%) 370 (98%) +write_8192 180 200 320 n.m. 380 (99%) 370 (97%) +rewrite_8192 190 200 340 n.m. 490 (87%) 350 (66%) +.TE +.DE +.ds RH Conclusions +.bp |