On Fri, Oct 11, 2019 at 05:31:27PM +0200, Greg Kroah-Hartman wrote:
On Thu, Oct 10, 2019 at 04:14:43PM +0100, Matthias Maennich wrote:
Now that the namespace value is not part of the __ksymtab entry name
anymore, we can simplify the implementation of EXPORT_SYMBOL*. By
allowing the empty string "" to represent 'no namespace', we can unify
the implementation and drop a lot redundant code. That increases
readability and maintainability.
As Masahiro pointed out earlier,
"The drawback of this change is, it grows the code size. When the symbol
has no namespace, sym->namespace was previously NULL, but it is now am
empty string "". So, it increases 1 byte for every no namespace
EXPORT_SYMBOL. A typical kernel configuration has 10K exported symbols,
so it increases 10KB in rough estimation."
10Kb of non-swapable memory isn't good. But if you care about that, you
can get it back with the option to compile away any non-used symbols,
and that shouldn't be affected by this change, right?
Rasmus suggested to put the 'aMS' flags on the __ksymtab_strings section
to mitigate this:
https://lore.kernel.org/lkml/f2e28d6b-77c5-5fe2-0bc4-b24955de9954@xxxxxxxxxxxxxxxxxx/
I was not yet able to properly test this, so I did not include it in
this series. As I said in the cover letter, this 4th patch might be
optional for 5.4. So, we could defer it to a later time when we have
addressed that properly.
Cheers,
Matthias
That being said, the code is a lot cleaner, so I have no objection to
it.
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
