x86/fpu: Fix stale comments about lazy FPU logic
authorIngo Molnar <mingo@kernel.org>
Sat, 23 Sep 2017 13:00:13 +0000 (15:00 +0200)
committerIngo Molnar <mingo@kernel.org>
Tue, 26 Sep 2017 07:43:43 +0000 (09:43 +0200)
commit7f1487c59b7c6dcb20155f4302985da2659a2997
treed1fad1b0468bf6022e86af0cd9e7f68548218767
parente4a81bfcaae1ebbdc6efe74e8ea563144d90e9a9
x86/fpu: Fix stale comments about lazy FPU logic

We don't do any lazy restore anymore, what we have are two pieces of optimization:

 - no-FPU tasks that don't save/restore the FPU context (kernel threads are such)

 - cached FPU registers maintained via the fpu->last_cpu field. This means that
   if an FPU task context switches to a non-FPU task then we can maintain the
   FPU registers as an in-FPU copies (cache), and skip the restoration of them
   once we switch back to the original FPU-using task.

Update all the comments that still referred to old 'lazy' and 'unlazy' concepts.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/20170923130016.21448-31-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/kernel/fpu/core.c