According to POSIX.1-2001, the CLOCK_PROCESS_CPUTIME_ID and
CLOCK_THREAD_CPUTIME_ID clocks should be settable, but
currently they are not.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
s/2.6.20/2.6.30/ to fix an earlier typo in the description
of the likely kernel version that will have fully fledged
real-time features.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Rework the text that refers to sched_setscheduler(2) for
a description of the permissions required to change
the scheduling policy and priority.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
In particular, note that in each pthreads function that takes
a thread ID argument, that ID by definition refers to a thread
in the same process as the caller.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
On MacOS X at least, pthread_attr_setstacksize(3) can fail
with EINVAL if 'stacksize' is not a multiple of the system
page size. Best to mention this so as to aid people writing
portable programs.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reported-by: Karsten Weiss <knweiss@gmail.com>
==
From: Karsten Weiss <knweiss@gmail.com>
Date: Fri, Oct 31, 2008 at 3:46 PM
Subject: pthread_create(3) - example bug + problems
[...]
A look in the pthread_set_stacksize man page on Mac revealed that on
Mac the stack size must not only be at least PTHREAD_STACK_MIN...
[...]
...but the new stack size must also be a multiple of the system page
size!
From pthread_attr_setstacksize(3):
pthread_attr_setstacksize() will fail if:
[EINVAL] Invalid value for attr.
[EINVAL] stacksize is less than PTHREAD_STACK_MIN.
!!! [EINVAL] stacksize is not a multiple of the system page size.
See for yourself (PTHREAD_STACK_MIN==8192 on Mac OS X):
$ ./pthread_test -s $((8192*10-1)) a
pthread_attr_setstacksize: Invalid argument
$ ./pthread_test -s $((8192*10)) a
Thread 1: top of stack near 0xb0014f6c; argv_string=a
Joined with thread 1; returned value was A
$ ./pthread_test -s $((8192*10+1)) a
pthread_attr_setstacksize: Invalid argument
The bug is in this part of the code:
/* Allocate memory for pthread_create() arguments */
tinfo = calloc(num_threads, num_threads);
if (tinfo == NULL)
errExit("calloc");
The calloc() line should read like this instead:
tinfo = calloc(num_threads, sizeof(struct thread_info));
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Add text to CONFORMING TO explaining that the "_np"
suffix is because these functions are non-portable.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reported-by: Karsten Weiss <K.Weiss@science-computing.de>
EFAULT can't occur for these functions. EINVAL can occur
for invalid 'attr' or 'cpuset' arguments.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
s/\.R " "/\\\&/ as a way of getting a blank line after a .SS heading.
(Suggested by Sam Varshavchik <mrsam@courier-mta.com>)
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
For sched_setaffinity(), the EINVAL error that occurs
if 'cpusetsize' is smaller than the kernel CPU set size only
occurs with kernels before 2.6.9.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
So on a direct syscall, the EINVAL could also occur for bufsiz < 0.
But at the moment, the error text is sufficiently vague
("bufsiz is not positive") that a change to the man page text
is probably not needed.
Michael Kerrisk