Re: [PATCH v2 4/6] x86: Rewrite switch_to() code

From	Josh Poimboeuf <jpoimboe@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 4/6] x86: Rewrite switch_to() code
Date	2016-06-20 17:50 +0200
Message-ID	<rM9Cx-1EU-7@gated-at.bofh.it> (permalink)
References	<rLvvr-F3-3@gated-at.bofh.it> <rLvvr-F3-1@gated-at.bofh.it>
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On Sat, Jun 18, 2016 at 04:56:16PM -0400, Brian Gerst wrote:
> Move the low-level context switch code to an out-of-line asm stub instead of
> using complex inline asm.  This allows constructing a new stack frame for the
> child process to make it seamlessly flow to ret_from_fork without an extra
> test and branch in __switch_to().  It also improves code generation for
> __schedule() by using the C calling convention instead of clobbering all
> registers.
> 
> Signed-off-by: Brian Gerst <brgerst@gmail.com>

You can also remove the STACK_FRAME_NON_STANDARD annotation for
__schedule() in kernel/sched/core.c since it no longer produces an
objtool warning.

Otherwise it looks great:

Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>

-- 
Josh

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[PATCH v2 4/6] x86: Rewrite switch_to() code Brian Gerst <brgerst@gmail.com> - 2016-06-18 23:00 +0200
  Re: [PATCH v2 4/6] x86: Rewrite switch_to() code Andy Lutomirski <luto@amacapital.net> - 2016-06-19 23:30 +0200
  Re: [PATCH v2 4/6] x86: Rewrite switch_to() code Josh Poimboeuf <jpoimboe@redhat.com> - 2016-06-20 17:50 +0200

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