* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > On Tue, Mar 28, 2017 at 09:52:32AM +0200, Ingo Molnar wrote: > > > No, regular C code. > > > > I don't see the point of generating all this code via CPP - it's certainly not > > making it more readable to me. I.e. this patch I commented on is a step backwards > > for readability. > > Note that much of the atomic stuff we have today is all CPP already. Yeah, but there it's implementational: we pick up arch primitives depending on whether they are defined, such as: #ifndef atomic_read_acquire # define atomic_read_acquire(v) smp_load_acquire(&(v)->counter) #endif > x86 is the exception because its 'weird', but most other archs are > almost pure CPP -- check Alpha for example, or asm-generic/atomic.h. include/asm-generic/atomic.h looks pretty clean and readable overall. > Also, look at linux/atomic.h, its a giant maze of CPP. Nah, that's OK, much of is is essentially __weak inlines implemented via CPP - i.e. CPP is filling in a missing compiler feature. But this patch I replied to appears to add instrumentation wrappery via CPP which looks like excessive and avoidable obfuscation to me. If it's much more readable and much more compact than the C version then maybe, but I'd like to see the C version first and see ... > The CPP help us generate functions, reduces endless copy/paste (which induces > random differences -- read bugs) and construct variants depending on the > architecture input. > > Yes, the CPP is a pain, but writing all that out explicitly is more of a > pain. So I'm not convinced that it's true in this case. Could we see the C version and compare? I could be wrong about it all. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
