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#67 Sed - High CPU/IO

sed 4.2.2 future
open
nobody
SED (1) gnv301 (13) gnv213 (4)
4
2014-04-11
2013-08-09
John Malmberg
No

VMSPORTS TICKET #51 - SED High CPU/IO

SED - high CPU/IO as identified during execution of configure scripts.
Cause is currently unknown.

Discussion

  • John Malmberg

    John Malmberg - 2014-01-14
    • Group: sed --> sed 4.2.2
     

  • John Malmberg

    John Malmberg - 2014-01-26

    Testing the "sed -f dc.sed dc.inp" from the testsuite directory appeared to show the same symptoms.

    Building sed 4.4.2 runs this test 10 seconds longer on a 600 Mhz DS10 running OpenVMS 8.4 than sed V3.02 from the GNV 2.1.3 kit.

    Changing sed to use read() instead of getc() did not change the execution time for this test.

    It is not known if this is the same issue as seen when running configure scripts. The issue shows up in when the configure runs the config.status script.

     

    Last edit: John Malmberg 2014-01-28

  • Ishan Srivastava

    Ishan Srivastava - 2014-02-21

    While focusing only on this particular test case, SED spends most of its time in the 'execute_program()' function in execute.c file.
    Mainly doing substitution from do_subst() function.

    The ck_getline() from utils.c file looks like it's working fine.
    The file read/write activities also, do not seem to cause performance bottlenecks.

    The do_subst() and in fact the execute.c file, differs significantly from its equivalent code in the older version from GNV 2.1-3 kit.

    I do not see why this function would be causing performance issues when in fact it has been optimized over its predecessor.

     

  • John Malmberg

    John Malmberg - 2014-04-11
    • Description has changed:

    Diff:

    --- old
+++ new
@@ -1,3 +1,4 @@
 [VMSPORTS TICKET #51 - SED High CPU/IO](https://sourceforge.net/p/vms-ports/tickets/51/)

-SED - high CPU/IO as identified during execution of configure scripts. It is believed that this is the result of single character I/O to / from files. Rather than a block read() or write().
+SED - high CPU/IO as identified during execution of configure scripts.
+Cause is currently unknown.
    • Group: sed 4.2.2 --> sed 4.2.2 future