Re: [PATCH 20/22] x86,word-at-a-time: Remove .fixup usage

On Wed, Nov 10, 2021 at 10:46:42AM +0000, David Laight wrote:

From: Peter Zijlstra

quoted

Sent: 09 November 2021 21:08

...

quoted

GCC does the same, but I wanted to have the exception stuff be in
.text.cold, but alas it doesn't do that. I left the attribute because of
it's descriptive value.

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 Unless the cold attribute is helping move
("shrink-wrap"?) the basic block to a whole other section
(.text.cold.)?

I was hoping it would do that, but it doesn't on gcc-11.

Wouldn't moving part of a function to .text.cold (or .text.unlikely)
generate the same problems with the stack backtrace code as the
.text.fixup section you are removing had??

GCC can already split a function into func and func.cold today (or
worse: func, func.isra.N, func.cold, func.isra.N.cold etc..).

I'm assuming reliable unwind and livepatch know how to deal with this.