Dmitry:
On Wednesday 24 January 2007 04:08, Dmitry Adamushko wrote:
> On 23/01/07, Jeff Weber <[EMAIL PROTECTED]> wrote:
> > Dimitry:
> > > ...
> > > exceptions (CPU exceptions, e.g. page faults). I presume, you have
> > > done mlockall(CURRENT | FUTURE), haven't you?
> >
> > Yes. my Linux application follows this this model:
> >
> > main () {
> > mlockall(MCL_CURRENT | MCL_FUTURE);
> > rt_task_shadow( ... ) // become a realtime thread
> >
> > // for N threads:
> > rt_task_spawn( ... ) // fork off child RT thread
> > }
> >
> > It is one of the child RT threads that encounters the SIGXCPU unwanted
> > mode switch. It this the correct way to call mlockall() ?
>
> Looks ok. Just to avoid getting into the same trap twice. You don't
> use system(), fork() or alike beasts in your code, do you?
No.
BTW, a primary mode thread in my application encountered the page fault
writing to the BSS segment.
How would my application encounter a page fault after calling
mlockall(CURRENT | FUTURE) ?
Perhaps an answer is that mlockall() prevents pages from ever being paged out,
but the application may still encounter page faults upon referring to pages
that were never paged in when mlockall() was called. If true, then my
application may continue to encounter page faults, and hence switches to
seondary mode until all pages in the application are loaded.
Could you, or any Linux+Xenomai memory paging expert comment on how/when pages
for an application are loaded?
Is it possible to load all the text, bss and "initial" (initial data segment
from ELF load image + thread stacks) data pages for an application before
calling mlockall() ?
thanks,
Jeff
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