A NOTE has been added to this issue. 
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http://austingroupbugs.net/view.php?id=1111 
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Reported By:                torvald
Assigned To:                
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Project:                    1003.1(2013)/Issue7+TC1
Issue ID:                   1111
Category:                   Base Definitions and Headers
Type:                       Clarification Requested
Severity:                   Objection
Priority:                   normal
Status:                     Resolved
Name:                       Torvald Riegel 
Organization:               Red Hat 
User Reference:              
Section:                    pthread_rwlock_rdlock/pthread_rwlock_tryrdlock (XSH,
3 System Interfaces)  
Page Number:                (page or range of pages) 
Line Number:                (Line or range of lines) 
Interp Status:              --- 
Final Accepted Text:        http://austingroupbugs.net/view.php?id=1111#c4042 
Resolution:                 Accepted As Marked
Fixed in Version:           
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Date Submitted:             2017-01-04 23:06 UTC
Last Modified:              2019-11-07 16:59 UTC
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Summary:                    pthread_rwlock_rdlock requirements if TPS is
supported are under-specified, error-prone for users, and inefficient
====================================================================== 

---------------------------------------------------------------------- 
 (0004639) eblake (manager) - 2019-11-07 16:59
 http://austingroupbugs.net/view.php?id=1111#c4639 
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This was discussed again on the 2019-11-07 call, in response to
http://austingroupbugs.net/view.php?id=1111#c4545. Since TPS is optional, the
consensus on the call was that
Linux has a bug for advertising TPS when it cannot actually support it. One
recommendation would be for Linux/glibc to fix their headers to define
_POSIX_THREAD_PRIORITY_SCHEDULING to 0, rather than a positive value, and
have sysconf(_SC_THREAD_PRIORITY_SCHEDULING) return -1.  However, this may
break existing code that currently checks for a non-zero value (but does
not care whether that value is specifically 200809L).

It may also be worth defining a value that would allow implementations to
know if the interfaces are supported but the thread scheduling guarantees
might not be, as an intermediate position between missing and fully
supported, whether as the compile-time value or as a result from sysconf,
and/or adding a new optional thread scheduling policy to POSIX where Linux
implements _that_ policy instead of TPS.  But such proposals do belong as a
separate bug.  I will work with the glibc folks to see what we can come up
with.  See more at https://bugzilla.redhat.com/show_bug.cgi?id=1410052#c17 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2017-01-04 23:06 torvald        New Issue                                    
2017-01-04 23:06 torvald        Name                      => Torvald Riegel  
2017-01-04 23:06 torvald        Organization              => Red Hat         
2017-01-04 23:06 torvald        Section                   =>
pthread_rwlock_rdlock/pthread_rwlock_tryrdlock (XSH, 3 System Interfaces) 
2017-01-04 23:06 torvald        Page Number               => (page or range of
pages)
2017-01-04 23:06 torvald        Line Number               => (Line or range of
lines)
2017-01-05 02:13 bhaible        Note Added: 0003528                          
2017-01-05 10:31 bhaible        Issue Monitored: bhaible                     
2017-01-05 12:00 torvald        Note Added: 0003534                          
2017-01-05 12:15 bhaible        Note Added: 0003535                          
2017-01-05 15:56 shware_systems Note Added: 0003536                          
2017-01-06 13:21 praiskup       Issue Monitored: praiskup                    
2017-01-06 13:34 praiskup       Note Added: 0003538                          
2017-01-07 09:06 Florian Weimer Issue Monitored: Florian Weimer                 
  
2017-01-10 11:48 torvald        Note Added: 0003540                          
2018-06-14 16:15 geoffclare     Note Added: 0004042                          
2018-06-14 16:16 geoffclare     Note Edited: 0004042                         
2018-06-14 16:17 geoffclare     Interp Status             => ---             
2018-06-14 16:17 geoffclare     Final Accepted Text       =>
http://austingroupbugs.net/view.php?id=1111#c4042    
2018-06-14 16:17 geoffclare     Status                   New => Resolved     
2018-06-14 16:17 geoffclare     Resolution               Open => Accepted As
Marked
2018-06-14 16:17 geoffclare     Tag Attached: tc3-2008                       
2019-08-30 00:41 eblake         Note Added: 0004545                          
2019-11-07 16:59 eblake         Note Added: 0004639                          
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