Patch-ID# 101520-02
Keywords: semaphore optimizations ipcs
Synopsis: SunOS 5.3: ipcs/semaphore fixes
Date: Aug/02/94

Solaris Release: 2.3

SunOS release: 5.3

Unbundled Product:

Unbundled Release:

Topic: SunOS 5.3: ipcs/semaphore fixes

BugId's fixed with this patch: 1145619 1137598 1122375 1149376 1146296 1137598 1168646

Changes incorporated in this version: 1168646

Relevant Architectures: sparc

Patches accumulated and obsoleted by this patch:

Patches which conflict with this patch:

Patches required with this patch:

Obsoleted by:

Files included with this patch:

/usr/bin/ipcs
/kernel/sys/semsys 

Problem Description:

1168646 ipcs does not reliably return information about all

ipcs(1) does not reliably return information about all allocated semaphore 
segments.  The semaphore ID assignment algorithm was changed in 5.3 patch
101520, but ipcs(1) wasn't changed to match, so when a semaphore ID is
assigned out of the previously usual sequence (greater than 65535), ipcs
wouldn't show it.

(from 101520-01)

1145619 SVR4 semaphore operations could be optimized
1137598 semaphore code-optimizations (sem.c)
1122375 Sys V semaphore locks has too much contention
1149376 Memory leak in SVR4 semaphores
1146296 PANIC in System V IPC/Semaphore code
1137598 semaphore code-optimizations (sem.c)

Performance of the semaphore test program is very poor. As the number of CPU's 
increase the performance drops. 

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