Bug 1295892 - rhel6+ ksh regression due to default to mmap for internal malloc
rhel6+ ksh regression due to default to mmap for internal malloc
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: ksh (Show other bugs)
All All
medium Severity medium
: rc
: ---
Assigned To: Siteshwar Vashisht
BaseOS QE - Apps
Depends On:
Blocks: 1269194 1460944
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Reported: 2016-01-05 12:29 EST by Paulo Andrade
Modified: 2017-06-13 04:39 EDT (History)
4 users (show)

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Fixed In Version:
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Story Points: ---
Clone Of:
: 1460944 (view as bug list)
Last Closed: 2017-06-13 04:39:39 EDT
Type: Bug
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
kshscript (1.41 KB, text/plain)
2016-01-05 12:29 EST, Paulo Andrade
no flags Details

  None (edit)
Description Paulo Andrade 2016-01-05 12:29:44 EST
Created attachment 1111915 [details]

The example script, when run as:

$ ./kshscript driver

will run around 5 times slower in rhel6+ when compared
to rhel5 version of ksh.

  A possible workaround is to run as:

VMALLOC_OPTIONS=break ./kshscript driver

to have the same behavior as rhel5 ksh.

  Another solution is to use system malloc, e.g. have
-D_AST_std_malloc=1 in CFLAGS, what will cause it to
make very few mmap calls and run fast as well (but
make VMALLOC_OPTIONS a noop).

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