On Fri, Mar 22, 2013 at 09:55:53AM -0400, [email protected] wrote: > On Fri, 22 Mar 2013 13:41:25 +0800, ishare said: > > Is it needed or must to compile fs and driver with -O2 option when > > compiling kernel ? > > It's not strictly mandatory to use -O2 (for a while, -Os was the default). > There > are a few places that for correctness, you *cannot* use -O0. For instance, a > few places where we use builtin_return_address() inside an inline (-O0 > won't inline so builtin_return_address() ends up returning a pointer to > a function when we want the function's parent). So it will cause an error ? > > Since gdb and friends are able to deal with -O2 compiled code just fine, > there's really no reason *not* to optimize the kernel.
the debug information will be stripped by -O2 ,for example ,you can not touch the value of some varibles at stack , and debugging will not run line by line, instead , the source jump in unexpectable order . _______________________________________________ Kernelnewbies mailing list [email protected] http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
