On Mon, Aug 14, 2023 at 08:12:55AM +0000, David Laight wrote: > From: Andy Shevchenko > > Sent: 10 August 2023 14:14 > > On Wed, Aug 09, 2023 at 08:48:54AM +0000, David Laight wrote: ... > > > > If you split headers into so many small pieces then all > > > > source files will start with 3 screens of includes. I do not see > > > > how this helps with maintainability. > > > > > > You also slow down compilations. > > > > Ingo's patches showed the opposite. Do you have actual try and numbers? > > The compiler has to open the extra file on every compile. > If you include it from lots of different places it has to open > it for each one (to find the include guard). > Any attempted compiler optimisations have the same much the > same problem as #pragma once. > > With a long -I list even finding the file can take a while. > > Probably most obvious when using NFS mounted filesystems. > Especially the 'traditional' NFS protocol that required a > message 'round trip' for each element of the directory path. Right, as I said come up with numbers. Ingo did that, so can you. His numbers shows _increase_ of build speed. -- With Best Regards, Andy Shevchenko
