Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9c27d77d authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

Documentation/volatile-considered-harmful.txt: convert to ReST markup 



- Fix document section markups;
- use quote blocks where needed;
- adjust spaces and blank lines;
- add it to the development-processs book.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 27641b95

Documentation/volatile-considered-harmful.txt

+11 −8
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ need to use volatile as well. If volatile is still necessary, there is 
almost certainly a bug in the code somewhere.  In properly-written kernel

code, volatile can only serve to slow things down.



Consider a typical block of kernel code:

Consider a typical block of kernel code::



    spin_lock(&the_lock);

    do_something_on(&shared_data);
@@ -57,7 +57,7 @@ optimization, so, once again, volatile is unnecessary. 


Another situation where one might be tempted to use volatile is

when the processor is busy-waiting on the value of a variable.  The right

way to perform a busy wait is:

way to perform a busy wait is::



    while (my_variable != what_i_want)

        cpu_relax();
@@ -103,17 +103,20 @@ they come with a justification which shows that the concurrency issues have 
been properly thought through.





NOTES

-----

References

==========



[1] http://lwn.net/Articles/233481/



[2] http://lwn.net/Articles/233482/



CREDITS

-------

Credits

=======



Original impetus and research by Randy Dunlap



Written by Jonathan Corbet



Improvements via comments from Satyam Sharma, Johannes Stezenbach, Jesper

Juhl, Heikki Orsila, H. Peter Anvin, Philipp Hahn, and Stefan

Richter.