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Full Discussion: semaphore access speed
Top Forums Programming semaphore access speed Post 302239677 by otheus on Wednesday 24th of September 2008 08:14:17 AM
Old 09-24-2008
Quote:
Originally Posted by jim mcnamara
SCO has kernel parameter issues with semphores. SHMMAX parameter by default is small. This is a known issue. Here is SCO docset for installing Postgres that discusses it.

Managing Kernel Resources
Jim, Are you thinking that the size of SHMxxx parameters influences the performance?

Migurus,

What do you have set for your Linux shared memory settings? "/sbin/sysctl -a |grep shm". (Ignore errors). Compare those to what is set for SCO (I don't know how to get those).
 

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CFREE(3)						     Linux Programmer's Manual							  CFREE(3)

NAME
cfree - free allocated memory SYNOPSIS
#include <stdlib.h> /* In SunOS 4 */ int cfree(void *ptr); /* In glibc or FreeBSD libcompat */ void cfree(void *ptr); /* In SCO OpenServer */ void cfree(char *ptr, unsigned num, unsigned size); /* In Solaris watchmalloc.so.1 */ void cfree(void *ptr, size_t nelem, size_t elsize); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): cfree(): _BSD_SOURCE || _SVID_SOURCE DESCRIPTION
This function should never be used. Use free(3) instead. 1-arg cfree In glibc, the function cfree() is a synonym for free(3), "added for compatibility with SunOS". Other systems have other functions with this name. The declaration is sometimes in <stdlib.h> and sometimes in <malloc.h>. 3-arg cfree Some SCO and Solaris versions have malloc libraries with a 3-argument cfree(), apparently as an analog to calloc(3). If you need it while porting something, add #define cfree(p, n, s) free((p)) to your file. A frequently asked question is "Can I use free(3) to free memory allocated with calloc(3), or do I need cfree()?" Answer: use free(3). An SCO manual writes: "The cfree routine is provided for compliance to the iBCSe2 standard and simply calls free. The num and size argu- ments to cfree are not used." RETURN VALUE
The SunOS version of cfree() (which is a synonym for free(3)) returns 1 on success and 0 on failure. In case of error, errno is set to EINVAL: the value of ptr was not a pointer to a block previously allocated by one of the routines in the malloc(3) family. CONFORMING TO
The 3-argument version of cfree() as used by SCO conforms to the iBCSe2 standard: Intel386 Binary Compatibility Specification, Edition 2. SEE ALSO
malloc(3) COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2007-07-26 CFREE(3)
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