Messages in this thread |  | | | Date | Thu, 20 Aug 1998 16:27:45 -0600 | | From | Richard McRoberts <> | | Subject | 2.1.xxx makes Electric Fence 22x slower |
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Kernel 2.1.117 makes Electric Fence very slow and tedious.
Here are timings of Berkeley Spice 3, linked both with and without Electric Fence, run under 2.1.117 (w/o SMP) vs 2.0.34.
Elapsed time in seconds 2.0.34 2.1.117 ----------------------- ------ ------- Without Electric Fence 3.82 3.72
With Electric Fence 14.61 325.85 (!)
No swapping was involved; at least 90-100MB seemed to remain free on my system at all times. As indicated by "top", Spice's memory footprint (with efence) was only 15MB. My system has 128MB RAM (Intel P-II-266 w/ RedHat 5.1). Each measurement was made with GNU "time" (subjective impressions were similar) immediately after a fresh reboot. Spice3 was run on a VT without starting X. It was given a moderately complex input file to work on. Spice3 gets many memory allocations in small pieces, and frees a few of them as it goes along.
Anyone should be able to duplicate this result with spice-3f4-4.src.rpm from redhat contrib/hurricane, linking it with libefence, and giving it ltra_1.cir (from the spice-examples binary rpm that the src rpm also builds) as input with the following command:
echo "set noquitsave; run; print all; quit" | time ./spice3 -i ltra_1.cir Spice emits some complaint messages as it runs, but the overall slowdown is quite clear, and occurs with other circuit files also.
Before making this posting (my first), I searched this archive for mentions of Electric Fence. Seemingly they are rare and have not addressed this subject. Unfortunately I am not acquainted with the kernel internals.
Thanks for any help, and thanks to members of this list for your wonderful work in creating Linux.
Richard D. McRoberts Loveland, Colorado USA rdm@verinet.com
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