how to fix PTHREAD_STACK_MIN with large PAGE_SIZE

[Khem Raj]

On Fri, Aug 26, 2011 at 7:00 AM, Kamal Dasu <kdasu.kdev at gmail.com> wrote:
> Using uClibc 09.30.1  I hit a problem when running timers with SIGEV_THREAD
> option on a MIPS system with PAGE_SIZE>=16K.
> In uClibc pthread library PTHREAD_STACK_MIN is defined at 16K. This is used
> when creating a thread to set the default pthread_attr stack size. However
> implementations could have page_size >= 16K in which case the check for the
> minimum stack size in _pthread_create() will fail. The only fix seems to be
> increasing the value to 2* PAGE_SIZE. However a cleaner way to fix this
> would be increasing the PTHREAD_STACK_MIN based on the page size to make
> optimal use of resources. The patch below shows the only feasible way I
> could find to do this.
>
>
> Adjust stack size for PAGE_SIZE >= 16K. Needed to make timer uses
> SIGEV_THREAD attribute.

solution seems ok.

>
> ---
>  .../uClibc/libpthread/nptl/pthread_attr_setstack.c |    2 +-
>  .../libpthread/nptl/pthread_attr_setstacksize.c    |    2 +-
>
>  .../libpthread/nptl/sysdeps/pthread/pthread.h      |    1 +
>  .../nptl/sysdeps/unix/sysv/linux/bits/local_lim.h  |    3 ++-
>  4 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/uclinux-rootfs/lib/uClibc/libpthread/nptl/pthread_attr_setstack.c
> b/uclinux-rootfs/lib/uClibc/libpthread/nptl/pthread_attr_setstack.c
>
> index d400f3d..7327e7d 100644
> --- a/uclinux-rootfs/lib/uClibc/libpthread/nptl/pthread_attr_setstack.c
> +++ b/uclinux-rootfs/lib/uClibc/libpthread/nptl/pthread_attr_setstack.c
> @@ -49,7 +49,7 @@ __pthread_attr_setstack (
>
>   return 0;
>  }
>
> -#if PTHREAD_STACK_MIN == 16384
> +#if PTHREAD_STACK_MIN >= 16384

why is this needed

>  strong_alias(__pthread_attr_setstack, pthread_attr_setstack)
>  #else
>  weak_alias(__pthread_attr_setstack, pthread_attr_setstack)
>
> diff --git a/uclinux-rootfs/lib/uClibc/libpthread/nptl/pthread_attr_setstacksize.c
> b/uclinux-rootfs/lib/uClibc/libpthread/nptl/pthread_attr_setstacksize.c
> index 24e5b0a..d2ae5fe 100644
> --- a/uclinux-rootfs/lib/uClibc/libpthread/nptl/pthread_attr_setstacksize.c
>
> +++ b/uclinux-rootfs/lib/uClibc/libpthread/nptl/pthread_attr_setstacksize.c
> @@ -42,7 +42,7 @@ __pthread_attr_setstacksize (
>   return 0;
>  }
>
> -#if PTHREAD_STACK_MIN == 16384
> +#if PTHREAD_STACK_MIN >= 16384
>

same here

>  strong_alias(__pthread_attr_setstacksize, pthread_attr_setstacksize)
>  #else
>  weak_alias(__pthread_attr_setstacksize, pthread_attr_setstacksize)
> diff --git a/uclinux-rootfs/lib/uClibc/libpthread/nptl/sysdeps/pthread/pthread.h
> b/uclinux-rootfs/lib/uClibc/libpthread/nptl/sysdeps/pthread/pthread.h
>
> index deb7430..eeeefb7 100644
> --- a/uclinux-rootfs/lib/uClibc/libpthread/nptl/sysdeps/pthread/pthread.h
> +++ b/uclinux-rootfs/lib/uClibc/libpthread/nptl/sysdeps/pthread/pthread.h
> @@ -32,6 +32,7 @@
>  #include <bits/wordsize.h>
>
>  #if defined _LIBC && ( defined IS_IN_libc || defined NOT_IN_libc )
>  #include <bits/uClibc_pthread.h>
> +#include <bits/uClibc_page.h>
>  #endif
>
>
> diff --git a/uclinux-rootfs/lib/uClibc/libpthread/nptl/sysdeps/unix/sysv/linux/bits/local_lim.h
> b/uclinux-rootfs/lib/uClibc/libpthread/nptl/sysdeps/unix/sysv/linux/bits/local_lim.h
>
> index 8f0df4f..07cd5bd 100644
> --- a/uclinux-rootfs/lib/uClibc/libpthread/nptl/sysdeps/unix/sysv/linux/bits/local_lim.h
> +++ b/uclinux-rootfs/lib/uClibc/libpthread/nptl/sysdeps/unix/sysv/linux/bits/local_lim.h
> @@ -37,6 +37,7 @@
>
>
>  /* The kernel sources contain a file with all the needed information.  */
>  #include <linux/limits.h>
> +#include <pthread.h>
>
>  /* Have to remove NR_OPEN?  */
>  #ifdef __undef_NR_OPEN
> @@ -79,7 +80,7 @@
>
>  #define AIO_PRIO_DELTA_MAX     20
>
>  /* Minimum size for a thread.  We are free to choose a reasonable value.  */
> -#define PTHREAD_STACK_MIN      16384
> +#define PTHREAD_STACK_MIN ( (PAGE_SIZE == 4096) ? 16384 : PAGE_SIZE << 1 )
>
>
>  /* Maximum number of timer expiration overruns.  */
>  #define DELAYTIMER_MAX 2147483647
> --
>
>
> Kamal
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