Re: [RFC][PATCH 0/2] Lock and Pointer guards

From: Paolo Bonzini
Date: Mon May 29 2023 - 07:30:36 EST

On 5/26/23 17:05, Peter Zijlstra wrote:
My initial (failed) attempts tried to combine __cleanup, _Generic and
__auto_type, but the compilers refused. I've also Googled around and found
(among many others) the QEMU and Glib guards. However I don't like them because
they end up relying on function pointers/indirect calls.

Hence the current pile of CPP hackery.. no indirect calls in sight.

QEMU's guards in practice also compiles down to direct calls, but yes that's only after the compiler inlines everything in the vtable. I did it that way because the polymorphic locks already existed before, otherwise your solution with Linus's tweak for "bool" is as nice as it can be. I like that it extends to irqoff and irqsave sections.